Underground communications: concept, definition, design, construction. General information about underground communications Underground communications and building structures

Underground utilities are subdivided into pipelines, cable laying and collectors by their design. According to the type of transported material, pipelines are subdivided into water supply, sewerage, gas pipeline, heating and other industrial pipelines. By the method of material transportation pipelines divide:

• 1) on gravity, which include sewerage and drains;
• 2) pressure head, which include water supply, gas pipeline, heat supply, sewerage.

Cable grommets usually divided into Electricity of the net and low-current(telephone, telegraph, radio, alarm).

Collectors are engineering structures for joint laying of various networks, for example, heating and cable laying.

BREAKDOWN OF COMMUNICATIONS. SHEARING, REMOVING AXES FOR SHEEPING

Topographic plans, as well as longitudinal and transverse profiles, serve as initial materials for the design of underground utility lines. Topographic plans are compiled from the survey results and used to select the direction of the route. Profiles obtained according to the results of technical leveling and used to determine the altitude position engineering communications.

For breakdown of communications on the ground is compiled layout drawing, which shows:

• 1) axis of traces;
• 2) a diagram of the breakdown of communications from the geodetic reference network or existing buildings;
• 3) the length of the track;
• 4) coordinates of the angles of rotation and centers of the wells;
• 5) the distance between them;
• 6) point heights;
• 7) some other values ​​as needed.

Geodetic work begins with the placement of the axis on the terrain

routes from points of geodetic networks or some coordinated local objects (buildings of existing development, viewing wells of engineering communications, supports of power lines, etc.). For this, the angles of rotation of the axis of the track are taken out with a relative error of no more than 1: 2000. Rotation angles are set out in different ways: gates, perpendiculars, polar, linear or angular intersections. Straight-line sections are fixed with a theodolite, and the necessary distances are plotted along the axis of the route. The direction of the track is fixed with stakes every 5-10 m. At the same time, the edges of the trench are marked on both sides by laying a distance equal to half the width of the track on both sides of the axis of the track. For wells, their centers are outlined and the edges are indicated.

To secure the route, a castoff in the form of two pillars, buried to a depth of about 1 m at a distance of about 1.5 m from the edge of the trench; a board is nailed horizontally to the posts at a height of about 1 m from the ground. On the castoffs, the theodolite takes out the axis of the route and fixes it with nails. A mounting wire can be pulled between the nails.

INTRODUCTION

CABLE LINES
Lines of force
Communication lines

WATER PIPES

* Scheme of work of the central heating station

DOMESTIC SEWERAGE

Working chamber
Manhole covers and manhole covers

Water wells
Heat wells (chambers)
Sewer wells
Storm drainage
Associated drainage wells
Gas wells
Wells GTS

POINTS AND STATIONS

CONCLUSION

P O D Z E M N E I N G E N E R N E K O M M U N I K A C I

LIVE LECTURE

INTRODUCTION

From time immemorial, humanity has sought to comfortize its existence according to the maximum scheme. Today, in the new millennium, a person is so accustomed to convenience that the slightest decrease in the degree of comfort drives us into a frenzy and plunges us into a state of short-term depression.

But what provides a modern person with such a supercomfortable existence? .. Fast, high-quality, minimum labor-intensive satisfaction of his natural needs. That is, the opportunity to cook food on a gas stove, and not on a fire or in a stove (although this is the best option in terms of health), the opportunity to take hygiene measures with hot water, watch TV, write a letter using the Internet, and warm up in the cold winter by the battery. And so on, and so on. All this became possible thanks to the development and modernization of special conductors along which comfort elements move to a person - electricity, cold water, hot water, natural gas, information signals. As it is sung in one song: "Electricity, gas, telephone, running water, communal paradise without hassle and worries."

There are also guides through which waste (that is, become unnecessary) elements of comfort are diverted from us. This is a sewer. We washed something in water or washed ourselves with water, and it became useless. And putting a bucket in the kitchen under the dishwasher and taking its contents out every hour is completely uncomfortable. The same can be said about the toilet, the bathroom. Sewerage is, in fact, a plumbing "return".

The so-called engineering communications act as such supply and discharge channels.

Engineering communications are linear structures designed for the transport of matter and the transfer of energy.

All communications are divided into two large primary classification categories:

1. Pipeline lines

2. Lines of wires and cables

I want to warn you all right away: in this lecture we will consider only classical (as well as ideal) options and schemes. You will come across all sorts of nuances, particulars and deviations from the classic (as well as ideal) options and schemes in real life - that is, in the course of your work or ordinary life. Now let's get started ...

METHODS OF SUBSTANCE AND ENERGY TRANSFER

In addition to the underground method (which we will continue to consider) of transporting matter and transferring energy from one point to another, there are other methods:

Air transportation and transmission (pipelines and conductive lines
located above the ground)

Floating (on the water surface)

Underwater-bottom (at the bottom of a reservoir or watercourse)

Underwater-ground (inside the ground under a reservoir or watercourse) - the so-called. siphons

Now we will temporarily move on to a very strict and dry style of presenting the material, since the differentiation of engineering communications is an area of ​​technical knowledge where it is not recommended even for teachers to joke.

ABOUT PIPELINE LINES (underground, aboveground, etc.)

A pipeline is a hollow linear structure that has a cylindrical shape and serves to transport liquid and gaseous substances (including steam).

By design, pipelines are divided into two groups:

1. General use

2. Industrial (special) purpose

Depending on what kind of substance is transferred through the pipe, public lines are divided into two subgroups:

Water engineering communications

Gas engineering communications

Industrial pipelines according to the same criterion are divided accordingly into such subgroups as, for example:

Oil pipelines

Oil pipelines

Gasoline pipelines

Acid pipelines

Air ducts

Steam lines

Combined pipelines (for example, a slurry pipeline designed for
transportation of a mechanical mixture of liquid with certain solid
particles)

There is also such a thing as a garbage pipeline (or just a garbage chute), along which household waste moves under the influence of gravity. In our post-Soviet countries, a garbage chute exists only in multi-storey buildings.

In short, any liquid (with and without solid impurities) or gaseous substance, including steam, can be transported through the pipe.

By the way. And what is the overpass? .. This is not entirely from our region, of course, but the name speaks volumes, right? .. Who knows what it is? .. It is a road in the form of a bridge across another road (railroad or automobile). That's all.

UNDERGROUND ENGINEERING COMMUNICATIONS

In accordance with the primary separation of all engineering communications, underground communications are also divided into two categories:

1. Underground pipelines

2. Underground cable lines

But why do we call them underground? .. Because these lines are laid in the ground at one or another depth.

An even trickier question. And why are they being built exactly underground? .. The fact is that in the city this type of laying is the most acceptable - so that, as they say, wires and pipes underfoot do not get tangled and do not hit the head.

1. Underground pipelines for general use

2. Underground pipelines for industrial (special) purposes

We will only study underground pipelines for general use.

PUBLIC UNDERGROUND PIPELINES

Why are we talking about such pipelines as public utilities? .. Because these pipelines carry water and gas - that is, household substances that we use every day to maintain high-quality and mobile life.

They are accordingly divided into two subgroups:

Water underground pipelines

Gas underground pipelines

Water underground pipelines

Depending on what function these pipelines perform, they are divided into two types:

1. Supply water pipelines (pressure only)

2. Outlet (sewer) water pipelines - pressure and non-pressure

Depending on the temperature (and, therefore, the purpose) of the supplied water, the supplying water pipelines are divided into two types:

Cold (drinking) water pipelines

Hot water pipes (water intended for daily hygiene and
home heating)

Pipelines designed to supply residents settlement cold water, otherwise they are simply called plumbing.

The pipelines for supplying the settlement with hot water are laid in special trays with covering slabs (or with upper covering trays), and this linear structure is called a heating main.

Outlet water pipelines are designed to divert waste or excess water into a natural drainage system or canals. In this case, all drainage waters undergo (at least should undergo) preliminary treatment before they enter the watercourse or reservoir.

According to their functional purpose, diverting (sewer) water communications are divided into three types:

Household (household and fecal) sewerage

Storm (surface) drainage - to drain excess rain and melt water from
city ​​streets

Associated (ground) drainage (built along the heating main to remove excess
groundwater)

In addition, according to the method of transportation, the outlet water pipelines are divided into two types of a different nature:

Pressure pipelines

Non-pressure (gravity, gravity) pipelines

Pressure transportation is carried out by means of an artificially created pressure at pumping stations (SPS or BPS).

Gravity transportation of waste or excess water is carried out using a specially created slope of the pipeline in one direction or another - to where it is supposed to direct the water flow. Water by gravity (i.e. independently) under the action of natural gravity moves from the source of the drainage system to the first pumping station.

Gas underground pipelines

Gas pipelines are being built to transport natural gas to points of consumption.

According to the magnitude of the pressure, they are divided into three types:

1. Low pressure pipelines

2. Medium pressure pipelines

3. High pressure pipelines

CABLE LINES

A cable line is a linear engineering structure, consisting of two main parts, which are represented:

Energy conductor

Protective sheath

Depending on what exactly is transmitted - electric current or information signal - cable lines are divided into two groups:

1. Power (electrical) lines

2. Communication lines

Lines of force

Power lines are electrical cables that are designed to transfer electric current from the place of its production (generation) to the consumer.

According to the voltage of the electric current, the power lines of underground utilities are divided into two types:

High voltage lines

Low voltage lines

Communication lines

Communication lines are cable routes that are designed for high-quality transmission of information (information signal) over long distances. With the help of such communications, we are able to transmit and receive images, sound, texts in good quality.

They are divided into three types:

Wire lines (so-called twisted pair)

Coaxial lines

Fiber optic lines

Communication cables are usually laid in a channel - in a special pipe of one diameter or another.

Information, as we know, can also be transmitted using free electromagnetic waves (that is, without the participation of cables) in any environment - in air space, in water, in the ground, in the substance of the walls of buildings.

We have classified all underground utilities according to the “category-group- (subgroup) -type-type” scheme, that is, from general to particular. Such a scheme, although extremely necessary, is rather arbitrary and somewhat confusing - in terms of understanding and memorizing the presented material. Therefore, we will act differently - we will single out the functional types of underground utilities, the name and role of which clearly reflects their purpose.

So, we can logically divide all underground engineering communications within the city into eight functional types:

1. Plumbing

2. Heating main

3. Household sewerage

4. Rainwater drainage (storm drainage)

5. Ground sewerage (associated drainage of the heating main)

6. Gas pipeline

7. Electric lines

8. Communication lines (GTS) - city telephone network

Now you can relax a bit and move from a strict presentation of the material to a simple (if not to say "intimate") conversation about various types of underground utilities.

Let's take a short break now. Let's go outside, breathe in the gentle May air through a cigarette, and then with a fresh mind we will continue our, so to speak, technical get-together.

WATER PIPES

Water supply (together with sewerage) is a very ancient structure, from time immemorial used to supply the population of cities with drinking water good quality and its subsequent withdrawal into rivers or special depressions.

In the ancient cities of the world, which have long been considered relict and in which no one has lived for a long time, scientists have discovered a water supply and sewerage system - that is, special channels through which water flowed to people and flowed from them in an unknown direction. Such channels are made of stone or real metal pipes.

Today we have learned how to make pipes from plastic. Therefore, we divide all our underground water pipes into:

Cast iron

Steel

Non-metallic:

A) p / et (polyethylene)
b) pvc (polyvinyl chloride)
c) HDPE (low pressure polyethylene)

And I will tell you, my dears, that now it is even safer to drink water from non-metallic pipes than from metal ones. What a disgrace ... There will come a time when such rust will flow from the taps that none of our household kitchen filters will help. And as always, there is no money to replace pipes in provincial cities.

The main artery of the city's water supply network is called a water conduit. There are several water pipelines in large cities. A water conduit is a wide pipe with a diameter of 600 mm (sometimes slightly smaller), from which distribution pipes of a smaller diameter extend. A network of pipes with a smaller diameter is called an inter-block network. The inter-quarter network branches out into a courtyard network. And then the courtyard network turns into the so-called "interior", that is, into the intra-house pipelines. But we will not talk about it, it is not the subject of our conversation now. About her later.

Thus, the entire urban underground water supply network is divided into networks of three orders:

1. First order network (backbone network) - water conduits

2. Second order network (inter-quarter network)

3. Third order network (courtyard network)

This is a "law of nature": the lower the order of the network, the smaller the inner diameter of the pipe. AND this law applicable to all buried pipelines.

Water enters the water conduit from a water intake station, which is installed, as a rule, in the immediate vicinity of the river. Conclusion: the aqueduct is filled with wonderful natural water. In many cases, of course, water enters the conduit from a well, especially in large cities.

Of course, before the water enters the main pipe, it undergoes a multi-stage preparation so that it can be safely used in everyday life and even drunk.

By the way, you can drink cold tap water without first boiling it. But not recommended. Firstly, it is very cold, you can chill your throat, and secondly, the quality of our water is unstable. It changes all the time - sometimes for the better, then for the worse. In general, yes, you can drink. But I would not recommend it. Boiling is the surest way to ensure that the water fully meets all sanitary standards.

Constant pressure is maintained in the water conduit and in pipes of a lower order - the water in them is always under a certain pressure. It does not flow like a free stream inside the pipes, as some gentlemen-comrades think, but is constantly replenished from the water intake and thus slowly moves along the network as a whole, like a whole mass of water, filling the entire space of the pipes. There are a lot of people in the city, especially in a big city, the tap opens often, the pressure is constantly dropping. What can you do…

The depth of the water pipe in our Central Russian latitudes is from 1.8 m to 2.5 m. And why is this? It depends on the depth of soil freezing. North and south are very different in this regard, as you can imagine.

If we saw a pipe that is located above this range, then we say that this is an abnormal position, which can subsequently turn into serious troubles. For example, a heating main is being repaired. And what kind of heating mains do we have? .. That's right, rotten through and through. And the water supply just lies on the floor slab of this heating main, which is prohibited. The team, not suspecting anything, cheerfully begins repairs, the excavator bucket enters the ground and ... successfully breaks the water pipe running along the top of the heating main channel. That's all. Do what you want.

Plumbing is usually located below all communications. It should be so.

So, what else do we need to know about plumbing ...

Plumbing is an engineering communication that is channelless. This means that the pipe, which contains cold drinking water, goes directly into the ground. And pipes with hot water, as we know, are mainly located in special channels - that is, the outer side of the heat pipes does not come into contact with the ground. There is, of course, also channelless laying of heating networks. Well, let's talk about the heating mains channels a little later, when we get to the technical essence of these communications.

HEATTRASSA (and about the heat system as a whole)

A heating main is a two-pipe engineering communication, as a rule, enclosed in a special channel consisting of reinforced concrete trays and floor slabs. In some cases, instead of covering floor slabs, covering upper trays are used.

Floor slabs (or upper trays) cover the lower trays, providing reliable protection to the heat pipes.

The heating main is the most complex structure among all communications. For several reasons.

Firstly, a heating main is always two pipes, that is, a water supply pipe (straight pipe) and a water outlet pipe ("return").

Secondly, the construction of reinforced concrete canals is no less complicated process than the laying of the pipes themselves.

Thirdly, in order to prevent flooding of the heating main with groundwater (in those places where their level is higher than the level of the heating main), a system of associated drainage pipes is closely attached to the canal. This greatly complicates and delays the installation of the heating main.

Fourthly, the heat pipes themselves are enclosed in a shell made of special materials that minimize heat loss. Can you imagine a "bare" heat pipe? .. This is completely unacceptable, since the heat energy simply cannot reach the consumer, it will all be lost on the way to the central heating station. But this is more true for pipes of the old generation (for repairs). At present, such a practice is becoming more and more widespread: a leaky pipe is changed immediately to a pipe of a new generation - with a ready-made factory heat-insulating "wrapper". This greatly facilitates the work of replacing and installing old pipelines.

Fifth, it is necessary to build so-called expansion joints on heat pipes. Until now, we observe U-shaped expansion joints - bends of two pipes in the form of the letter "P" (as a rule, in a horizontal profile) through a certain distance. The compensator plays the role of a damper for pipe deformations, which arise as a result of periodic changes in the physical parameters of the coolant - water (its temperature, pressure). A U-shaped expansion joint is a good way to avoid problems associated with mechanical destruction of pipes, but today it is generally a relic of the past. Recently, they have learned to make straight movable expansion joints that are installed between pipes. On the line of the air heating main, the U-shaped expansion joint can have the shape of the letter "P" not only in the horizontal profile, but also in the vertical one.

Let's go further. Pressurized water enters the wide main heat pipe from the CHPP, where it undergoes preliminary preparation and colossal heating. From the main pipe, water is distributed through heat pipelines, which enter the central heating point, where hot water performs a certain heating work (later we will consider the principle diagram of the central heating station) - it gives off heat in heat exchangers. Further, already from the central heating station, the so-called distribution heating networks leave, which then enter the buildings where we are sitting, eternally freezing consumers of hot water and heating.

Thus, we can divide the entire heating network of the city into:

1. Networks of the first order (primary) - main heating pipelines

2. Second-order networks (intermediate) - the so-called. heat inputs (from main pipes to central heating station)

3. Networks of the third order (secondary) - distributing heating pipelines

Trunk heat pipes are made of steel and have a diameter of up to one and a half meters. Distributing heat pipes are made not only of steel, but also of special plastic, roughly speaking. We will not delve into the intricacies of chemical production today, it does not matter for us yet. Distribution pipes can be of different diameters - mainly up to 15 cm.

The depth of the heating main is higher than that of the water supply. Sometimes in general, the floor slab comes out, comparing with the surface - so that you can walk on it like on an excellent concrete road. Have you seen such paths? .. There are still many hatches on them, which get confused all the time underfoot.

In certain places, heat pipes come to the surface and go above the ground (mostly without a channel). In common people, such a heating main is called "air". Then she can re-enter the ground.

* Scheme of work of the central heating station

So now we can get to this. We said that the heated water from the heat input pipes enters the central heating station. What happens next? ..

Let's consider a classic scheme.

Central heating points are needed in order to implement the mechanism of operation of two main heating circuits:

Hot water circuit
- heating circuit

Let us first consider the mechanism of the hot water supply circuit.

Inside the central heating point, hot water from the supply heat pipe passes through special devices - heat exchangers for hot water supply, of which there are usually two:

Heat exchanger of the second heating stage
- heat exchanger of the first heating stage

The water taken from the supply heat pipe first enters the heat exchanger of the second heating stage, to which it gives off its heat. This heat is used to heat the water that is constantly circulating through this heat exchanger along the hot water supply circuit - from the central heating station to our taps and vice versa.

But where does the water come from in general to the hot water supply circuit? .. From the cold water supply pipe - that is, from the ordinary water supply system. But before entering this circuit, cold water passes through the heat exchanger of the first heating stage, where it is heated to a certain temperature and then sent to the hot water supply circuit.

That is, the role of the first stage heat exchanger is to heat cold tap water, and the role of the second stage heat exchanger is to continuously heat the already preheated water circulating along the hot water supply circuit. Heating and heating, as you understand, are two different things. Therefore, we must distinguish them without fail.

And we must also remember that the water from the supply heat pipe first passes through the second stage heat exchanger, and then through the first stage heat exchanger. This circulation path seems a little counterintuitive, but it only seems.

Hot water, which has given up its heat to the heat exchangers of hot water supply, returns to the heating network, but already into the second pipe. And we have already said that two heat pipes are suitable for the central heating station - supply and return. So, the "return" is just intended for the transportation of waste water in the opposite direction - to the CHP.

This is an indirect hot water supply scheme. But there is also a direct hot water supply, when hot water enters our tap directly from the supply heat pipe, bypassing the heat exchange mechanism. Direct water intake is practiced in older low-rise buildings.

Well, this is how hot water appears in our tap, which circulates in a circle - from the central heating station to the houses and vice versa. And the hot water in the batteries? .. It's a little more complicated here.

Hot water from the supply pipe also passes through another heat exchanger - the heat exchanger of the heating system - gives it heat and goes to the "return". Through this heat exchanger, another hot water circulates continuously (in winter) along an independent circuit (from the central heating station to the batteries in our houses and vice versa), which is heated by this heat exchanger to a certain temperature. The independent heating water circuit is constantly replenished with hot water drawn from the same supply pipe using a special booster pump. Such a make-up is necessary precisely because in the process of circulating hot water through the heating system, some of it is lost.

That is, we see the following diagram. Hot water in the tap is mainly cold tap water heated in heat exchangers. Hot water in batteries is a circuit, the water of which, circulating in a circle, constantly passes through another heat exchanger (heat exchanger of the heating system) and is heated in it; and this circuit is fed with water from the supply heat pipe. That is, cold tap water has nothing to do with a hot battery.

Difficult to understand? .. In fact, everything is very simple here. Over time, everything will clear up in consciousness and settle down.

This is, in fact, what is the great role of heating mains and, in particular, heat pipes.

DOMESTIC SEWERAGE

The domestic sewage system, where we discharge the waste of our life, can be called a plumbing "return". We have already mentioned this. But if the water in the water pipe fills its entire space, since it is under pressure, then the sewage water flows inside the pipe like a stream (up to the first pump station), leaving free space in the pipe.

Sewerage starts from the drain hole in the kitchen sink, in the sink, in the bathroom, in the toilet. These holes are the starting points for the entire sewer network of the city. That we don’t just throw there, what kind of water we don’t pour there ... Therefore, the sewage system is often clogged, overgrown with fats. In a word, the sewerage system is the most unclean underground utilities.

So, the dirty water, having got into the drain hole, passes through the sewer "interior" of the house and goes into the yard sewer pipes, which are connected to the inter-quarter sewer pipes.

From the last pipes, the dirty water, having become even more polluted, enters the city sewer gravity collectors - into fairly wide pipes designed for gravitational transportation of water to sewage pumping stations. All this path - from the drain hole to the first pump station - water makes its own, by gravity, that is, it flows relatively slowly under the influence of gravity, since all sewer pipes to the first pump station have a certain slope.

From the sewage pumping station, there is already a pressure sewer collector, through which water flows under pressure (under pressure) at a relatively high speed. Water is transported through the pressure sewer collector from the sewage pumping station further either to another sewage pumping station, or directly to the treatment facilities, in which the water is completely purified and sent to the nearest natural watercourse.

That's the whole sewage system.

The entire sewerage network, as well as the water supply system, can be divided into three orders:

1. First order network - yard sewer

2. Second-order network - inter-quarter sewerage ("initial" collectors)

3. Network of the third order - gravity and pressure collectors running
directly to the sewage pumping station and from the sewage pumping station

Sewer pipes, of course, like all other pipes, are made of both metal and plastic. The latter option is the most durable, since in general the sewer environment is very aggressive. Often, sinkholes occur exactly where the sewer collectors lie.

RAIN SEWERAGE (WATER DRAIN or SHOWER)

Rainwater drainage is otherwise called storm drainage or gutter (storm drain). This is a less significant form of sewage in social terms, but imagine if it did not exist at all. Showers and melted snow would constantly drown our streets, and with them - the basements of houses, thereby causing very great inconvenience.

So, most of the excess water entering the city streets from the atmosphere in the form of rain and melted snow (and in some cases, when rivers flood) ends up in the storm drainage system. But how? .. Through the grates of drainage wells (about wells later). Such wells in the general drainage network are designed to receive city waters and are therefore often called receiving wells.

Not all of the city's surplus street water, of course, goes into the drainage network. Some of it, of course, evaporates from the streets, the other part seeps into the ground.

We all know that rain, for example, knocks not only on asphalt, but also on roofs. We heard this in the songs, right? .. To drain water from the roofs, a special drain system is provided, consisting of receiving trays (gutters), funnels and drain pipes. Water falling on the roof of the building flows through it into the receiving gutters (gutters), located along the contour of the roof. From the trays, water flows into special funnels, and from them - into the house drainpipes, extending from the trays downward (to the ground). Downpipes can be located both outside the building (along the facade) and inside. From these pipes, water is poured either directly onto the asphalt (which is extremely bad), or into a tray on the asphalt of the sidewalk road (which is much more civilized) - into the so-called storm drain, which should be covered with a grill on top so as not to create inconvenience to pedestrians and drivers ... From the asphalt tray, water flows out of the curb (curb, if you like) and enters the roadway.

These gutters (on roofs) and storm gutters (on roads) are U-shaped (i.e. open at the top) pipes that can be made from a wide variety of materials. The easiest way to make such a tray is to cut the pipe in half lengthwise (i.e. lengthwise).

So, some part of the rainwater flowing through the streets to certain depressions in the relief falls into the receiving well. In the well, water rises to the level of the branch pipe (which is usually placed high) and is poured into it. The diameter of the drain pipe is much larger than that of the domestic sewage pipe. This width is set for a reason: together with water, it enters the well, and then into the pipe a large number of street garbage - sand, gasoline, dust, leaves, branches, pebbles, bags, bottles, cigarette butts and other attributes of the street. For all this mass to move through the pipe, a large diameter is required.

Further, the water mixed with street waste also moves under the influence of gravity (along the slope) and, in the end, enters the drainage collector, which leads the water into the river. Often, the water flowing through the drainage network does not pass any treatment facilities, but is discharged straight into the nearest watercourse. At the final exit, they simply put an ordinary metal grate, which partially traps large-scale street sewage, and supposedly clean water successfully replenishes the rivers of our cities, polluting them even more.

In general, the technical condition of the drainage system in provincial cities, of course, leaves much to be desired, since it is also often heavily littered and therefore does not fully fulfill its role. During a heavy downpour, water only fills the well, but naturally does not get into a pipe clogged with mud.

In the private sector, the drainage system is a network of gutters (artificial potholes) of varying depths and widths built along roads. Ideally, the water in such ditches should move along a slope, but even if there is none, then in any case, these canals still perform the role of drainage, because they accumulate all the "excess" water from the surrounding area. Sometimes domestic sewage water is deliberately discharged into such ditches, which is very harmful to the environment, of course. Any private sector should be equipped with a domestic sewerage network. At worst, you can build your own cesspool.

Comparative characteristics drainage and domestic sewerage

I must say that the scheme of operation of the drainage storm sewer is similar to the scheme of operation of the domestic sewage system. A significant difference is observed only in the diameter of the pipes. Let me remind you: the stormwater pipes are much wider than the pipes of the domestic sewage system. And what luxurious collectors are built on the drainage network, so I generally keep quiet about that. In metropolitan cities, such collectors represent whole tunnels - wide, with high brick or stone vaults - along the bottom of which a stream flows. And in provincial cities, I must say, drainage collectors have very wide pipelines.

As for the comparative cleanliness of the two networks - drainage and the sewer itself - here, too, they are generally the same. This is not to say that the water in the drain is cleaner than the water in the sewer, because the street is the main breeding ground for bacteria. And taking care of the purity of the drainage water at the final outlet is the primary task today.

Illegal incisions of drainage pipes into sewers are very often observed. And vice versa. Ideally, these networks should not intersect, that is, drainage water cannot enter the sewer network, and sewage water cannot enter the drainage network. Usually such illegal tapping is done in wells. Have you ever paid attention: you look into a household fecal well, and in it, in addition to a typical tray at the bottom, there is also a wide drainage pipe located above the tray? .. Pay attention. But such sidebars are not all. It also happens that rain and melt water flows directly into the sewer pipe - a cover with holes (grate) is installed on the sewer well, into which street water is poured.

It is the tie-in of drainage into the sewerage system that is a frequent cause of flooding of the sewage pumping station with rainwater during seasonal rainstorms.

Sometimes, in one well, you can observe several communications at once - both the water supply system, and the GTS, and the downpour (or simply the drain), and the sewerage ...

Now with regard to the depth of the drainage system. As a rule, the drain is always located above the domestic sewer. Has anyone looked into the clear drainage well? These wells are very shallow, the cut pipe in it is literally visible to the naked eye. And the sewer pipe and the tray must be viewed with a flashlight. If you're lucky, you won't have to climb into the well. But this applies for the most part to the collector wells of the domestic sewage system. And the yard decks of the same network are as shallow as the drainage ones.

Just like household sewerage, the drainage network is divided into orders:

1. First-order network - intra-block drainage (often delineates buildings)

2. Second order network - inter-quarter drainage (wider pipes)

3. Network of the third order - drainage collectors

Like domestic sewage, storm drainage is a channelless engineering communication (the pipe is laid directly in the ground).

And the last thing. We have already talked about this. Water from the domestic sewerage network must be purified before entering the reservoir. The drainage network in this regard remains to this day largely unsettled. True, recently modern filters have been installed directly in the drainage pipe. This, of course, minimizes the risk of dirty wastewater entering the rivers. But to reiterate: ideally, all drainage water, even if it has passed through these new filters, should be sent to sewage treatment plant... So far, such a scheme has not been adequately developed in provincial cities.

GROUND SEWERAGE (FLOOR DRAINAGE)

So that the heating main is not periodically flooded with groundwater, a so-called associated drainage is built on either side of it, which is a relatively wide drainage pipe into which groundwater is poured, thereby draining the soil around the heating main. This is necessary in order to protect the heating main from the pernicious influence of excess moisture, since it accelerates the destructive processes of the elements of thermal communications. Of course, all the seams are smeared at the joints of the trays and floor slabs (or upper covering trays), but water is such a substance that will penetrate anywhere and dissolve everything that gets in its way. Especially "vulnerable" heating main.

How does water get into these pipes? .. It's simple. The most common way is transverse cutouts in the pipe, into which groundwater is poured, then flowing according to the slope of the pipe.

The final outlet of the associated drainage is a rainwater drainage network. This is where the groundwater ultimately ends up. Thus, if we combine the associated and storm drainage into one whole, we will get a single powerful drainage network of the city. Sometimes grates (for rainwater seepage) are also placed on the wells of the associated drainage. And there is nothing so terrible in this, because constructing a separate (independent) system for removing groundwater into rivers is a laborious and expensive task. And it doesn't make any sense. It is necessary to build separate treatment facilities, look for and lay new paths and thereby create an even greater load on the geological foundation of the city, which is already barely holding on.

There are two types of associated drainage:

1. One-sided

2. Double-sided

One-way associated drainage is one drain pipe running from one side of the heating main. Double-sided associated drainage is two pipes, one of which runs along the heating main on one side, and the other on the opposite side.

Double-sided drainage is constructed where there is a large accumulation of groundwater - where one-sided drainage does not cope with its task.

Associated drainage is also a channelless utilities.

C O R U W E N I Z ON S E T Y X

The elements of underground engineering communications are not only the conductors of matter and energy (pipes or cables) and the channels in which they are located, but also special structures built in order to be able to access communications. Access is required for several reasons:

For inspection and assessment of technical condition

For cleaning pipelines

For the repair of communication

In order to be able to control the state of movement of matter and
energy

All of the above can be carried out in wells (in particular, in chambers), points and stations.

WELLS

Wells are the most common network structures. A well is a shaft of one depth or another, consisting of a base, a working chamber, a floor slab (PP), a neck and an upper head part - a hatch.

Building

Working chamber

The working chamber of the well is built of reinforced concrete rings (or brickwork- from the base to the hatch). A ladder is often installed in the working chamber - for a comfortable descent to the bottom of the well.

If the well is built of wide rings, then from above they are closed with a floor slab (PP) with a hole for the hatch, on which the hatch is installed. But if the working chamber of the well is narrow (the width of the rings is small), then instead of the floor slab, a narrowing reinforced concrete additional ring (DK) is installed on top, on which a hatch is installed.

If the well is made entirely of brickwork, then the hatch can be installed both on the additional ring (located on top), and directly on the upper row of bricks. The floor slab is not used in this case.

The well (and the chamber in particular) can also have a so-called neck. The neck is the brickwork at the top of the well. It is installed on the floor slab (when it is low) - including in order to be able to install a hatch. Suppose the lower part of the well is built of wide rings, on the last ring rests a floor slab with a hole, and from this hole to the earth's surface there is a relatively narrow brick neck, on which a hatch is mounted (also with or without an additional ring).

Manhole covers and manhole covers

The hatch is the top of the well. Hatches can be:

Cast iron
- plastic
- reinforced concrete (reinforced concrete)

Cast iron and plastic sunroof composed of:

Hatch bodies (shells)

Manhole covers (CL)

Reinforced concrete hatch is made up of reinforced concrete rings and reinforced concrete covers. But we know that there are also wooden hatches, right? .. An active carpenter from boards will make a completely even circle and independently close the open well in the yard. In general, a well without a cover is a serious malfunction, since it poses a threat to the life and health of the city's population, especially for children. It is good if the well is shallow, but if it has a depth of several meters. We all need to watch our steps, especially on a dark evening. And after the feast, you need to go accompanied by a less cheerful person.

Manhole covers in the plan may have the following shape:

Round (most common)
- rectangular
- square
- triangular
- oval
- complex

In a vertical profile, the shape of the hatch cover can be:

Flat
- convex
- concave (worst option)

By the number of ears, there are:

A) earless lids
b) 1-ear (with one large ear)
c) 2-ear
d) 3-ear
e) 4-ear
f) multi-eared (often such covers can be found on the wells of the GTS)

The ears are needed in order, firstly, to firmly fix the hatch cover in the grooves of the shell (body), and secondly, so that the maintenance personnel can easily, especially in winter, open the well with a hook for subsequent inspection. Although in severe frosts, the hatch cover freezes to the shell so that it has to be torn off for half an hour.

Accordingly, the hatch body can be:

Without grooves (grooves)
- with one recess
- with two recesses
- etc.

By the degree of relief of the outer surface of the lid, one can distinguish:

Smooth lids (not common)
- embossed covers (including patterned ones)

According to the cultivation capacity, all covers are divided into two types:

1 - permeable covers, or rainwater "grates" (must be installed
only on receiving drainage wells)
2 - waterproof covers (must be installed on all other wells)

The marking of manhole covers is regulated, but often the letter designation on the outside of the cover does NOT coincide with the type of underground service. For example, you can often see a sewer cover on water mains and vice versa.

There are the following main markings (letter designations):

"B" - water supply network

"K" - sewer network

"TS" - heating network

"D" - drainage network

"L" - storm drainage network

"GTS" - telephone network

Gas well manhole covers are painted, firstly, in red (less often in yellow), and secondly, in many cases they are convex or have a large thickness. On these grounds, gas wells are well distinguishable from the wells of other networks.

Well hatches vary in weight. On the territory of green zones, the lightest (plastic) hatches are installed, and on the roadway - the heaviest, since the load on the road is much greater than in the green zone, where, sometimes, for decades a cultured person has not set foot. Reinforced concrete covers are not installed on the roadways, since in these places the hatch cover must also be flush with the asphalt surface.

Manhole condition relative to the earth's surface

There are two fundamental concepts:

Inflated condition of the hatch
- understated condition of the hatch

But an understated or underestimated state is usually considered relative to something. What exactly? .. That's right, relative to the earth's surface.

In green areas, it is allowed (and moreover, it is recommended) to raise the level of the hatch, that is, to raise it to one or another height above the ground surface. There are also wells in the green zone, in which the upper ring of the working chamber extends almost completely to the surface. Above is a floor slab and a hatch crowns all this "splendor". Well, it also happens.

So, deliberately raising the well is allowed and allowed only in green areas. On the carriageway, the outer surface of the cover must necessarily lie in the same plane with the road surface. On sidewalks and inner-yard roads, the same location of the hatch is provided, but often we see a different picture. The hatch "sticks out", poor passers-by stumble over it in the dark, and cars are forced to go around this obstacle whenever possible.

But the underestimation of the hatch, even in green areas, is a serious flaw in the work. It also happens that the hatch has dropped by itself over time. This may indicate a partially destroyed upper part of the brickwork (including the neck) under the hatch or that there is some kind of defect in the floor slab, as well as in the additional ring.

K l a s i f i k a c i i k l o d ts e in

A well in a plan can have:

Round shape (most common)
- polygonal

Wells are installed in those places where:

The direction of communication changes sharply (rotary wells)
- the depth of its occurrence changes sharply (drop wells)
- there is a connection of several pipes (relatively small diameter) into one
relatively wide pipe - (nodal wells)
- there is an intersection of several pipes of the same communication on different levels
- there is a connection of two pipes (tap) - tie-in

Wells are also built on rectilinear (in a horizontal and vertical profile) sections of communications at a certain distance - in those places where there is a pipe connection. The larger the pipe diameter, the greater the distance between the wells. Such wells, installed in a straight line, are called linear.

Depending on which networks the wells belong to, they are divided into:

Plumbing (mark on the walls of buildings and poles - VK)
- thermal cameras (mark - TK)
- sewer (mark - KK or GK)
- storm and drainage (mark - LK)
- ground-drainage (associated drainage) - often without a mark or with a mark of DK
- gas pipe wells
- wells of the city telephone network (city telephone network), or communication wells (frequent mark -
Tel.)

As a rule, wells are not installed on underground power grids.

Water wells

Water wells can be divided into:

Water wells (on water lines)
- actually water wells (on the networks of inter-quarter and yard
water supply)

Fire hydrants (mark - PG) are mounted in water wells on straight sections, designed to take water from a water pipe for the purpose of mobile fire extinguishing. The fire hydrant is located vertically in the well. In Western countries, they are used to bringing hydrants to the surface.

On the water supply networks in the private sector, water columns are also installed.

Wide wells on water conduits are called plumbing chambers. They can be round or polygonal. To access such a chamber, not one hatch can be used, as in a "simple" well, but several.

Heat wells (chambers)

Thermal wells are polygonal, large in size and therefore called chambers. The heat chamber, as a rule, has several hatches for access to heat pipes and fittings (valves, etc.) - from two to six. But there are also small chambers with one hatch.

On air heating routes, the chamber is built on the surface and is a booth (mostly brick) of one size or another (depending on the size of the pipes).

Sewer wells

In the sewer well, the pipe is cut off and a tray is installed in the place of the cut.

All sewer wells can be divided into:

Gravity-collector
- pressure-collector
- wells of the inter-quarter network
- yard wells (in places where sewage water is discharged from houses)

All collector wells are deep enough, and in order to inspect the condition of their bottom, maintenance personnel have to climb there with a flashlight. In such an event, I must say, there is little pleasant. It must always be remembered that there are much fewer wells on pressure manifolds than on gravity ones.

Storm drainage

All wells belonging to this network are most conveniently divided into:

Reception

Lookout

The receiving well is primarily intended for receiving rainwater. The manhole cover at such a well is a lattice with holes of various shapes - round, longitudinal, figured. Rain or melt water is poured into these holes.

The inspection well is closed with a conventional waterproof cover and is NOT intended for water intake.

Associated drainage wells

These wells legally belong to heating networks, but objectively belong to the general drainage network of the city and practically do not differ from storm and drainage wells, and some of them are also used as reception wells.

Gas wells

It should be noted that the wells that are built on gas networks are quite small compared to the number of wells in other networks. In addition to this fact, recently there has been a tendency to dismantle gas pipe wells.

Carpets are also installed on the gas network - metal cylinders of red or (much less often) yellow with a lid. In green areas, the carpet cylinder may rise above the ground surface. On sidewalks and roadways, the carpet cylinder is entirely located inside the soil and roadway, and only the upper plane of the cover comes out to the surface. Opposite the carpet, on the nearest wall or pillar, a special yellow plate is drawn, which indicates the footage and other information.

As a child, everyone probably loved to hide something in the carpet. Yes, only in our case in the word "carpet" the stress falls on the first syllable, and not on the second.

Wells GTS

These wells have the most elegant hatches, it should be noted. Moreover, there are hatches of various shapes - for example, in the form of an oval cut off at the edges. And, what is interesting, there is always an inscription "ГТС" or "TELEPHONE" on the hatch cover of such wells. And therefore it is very easy to distinguish them from wells belonging to other communications.

The wells of the GTS are rather shallow. There is almost always a cover with a handle under the hatch. In the well, we see a cut pipe (channel) and slightly sagging cables.

Dead-end drainage wells *

Often, impassable wells (water supply, GTS) are unauthorizedly used for the so-called dead-end drainage of street water. There are two options here:

Direct dead-end discharge

Indirect dead-end drain

In the first case, a drain cover is installed on one or another impassable well, designed to receive street water. And the water is poured into the well in a direct way.

In the second case, water is poured into a water or telephone well from a drainage pipe and, by itself, does not go further. Active craftsmen "secretly" introduce one pipe (usually a wide one) into the well, and water from the streets is poured through it into the well and stands there until it evaporates and / or leaks into the ground.

We already know that not only water and telephone wells are used for unauthorized draining. Any well can be "perforated" and a pipe can be brought into it. If this is a sewage system, then there is no dead end as such - the water will still go into the sewer pipe. But in this case, there is a danger of overloading the household sewer network with excess (alien) water and excess garbage.

Basically, this illegal practice is widespread in those places where the storm and drainage network was not originally provided.

POINTS AND STATIONS

Among the points, the following structures on the networks can be distinguished:

Central heating station (TSP) - on heating networks
- gas control point (GRP; GRPSh) - on gas networks

Among the stations are:

Water intake station - on water supply networks
- sewerage pumping station (SPS) - on sewerage networks
- drainage pumping station (BPS) - on drainage networks (for draining soil
waters)
- transformer substation (TP) - on electrical networks
- telephone exchange (TS) - on the networks of the city telephone network

LAYING OF UNDERGROUND ENGINEERING COMMUNICATIONS

Pipe laying can be done in two ways:

1. By open method

2. In a closed way

The open method is, one might say, a classic of the genre. A pipe is lowered into a pre-dug trench, or - first a channel, and then pipes. The depth of the trench depends on the functional type of underground communication. This method is good where the trench does not violate the integrity of the road surface and the stationarity of urban building elements - that is, in empty green areas.

The closed method is a late invention. In another way, it is called the "puncture method". A conductor of matter or energy (pipe or cable) is dragged into the ground in a certain way, which avoids disrupting the integrity of the road surface and the stationarity of urban building elements.

IMAGE OF UNDERGROUND COMMUNICATIONS AND STRUCTURES ON THEM

Underground communications are depicted on special maps (filming). Each communication on the shoot is shown as a line (with all turns) of a certain color: for example, the water supply system is mostly blue, and the sewage system is brown. The hatches on the survey are shown as rounded dots of various sizes; cameras, points and stations - in the form of squares, triangles or rectangles of various sizes (CNS - often in the form of a circle).

The place where lines of communication of various types intersect is called an intersection. But it must be borne in mind that we are talking about an intersection in a horizontal profile. If we consider a vertical profile, then all communications, naturally, lie at a certain distance from each other - each communication is at its own depth.

CONCLUSION

How quickly time flies ... We, unfortunately, did not have time with you to study in more detail gas communications, underground power lines and underground cable communication lines. Well, these topics, therefore, you will study on your own, at home with a cup of Brazilian coffee from the suburbs.

If you forgot to say something or got confused with what - sorry, my grandfather has become very old, but not very adequate, and my head already, sorry, does not work as it did 45 years ago, when I was still a simple mustache teacher and was just starting my career. At that time, by the way, all the truants were getting bad marks from me. And now it's the other way around: less people means more oxygen. Why do I speak so badly about myself? .. Then, that the university is such a place where students practically independently study this or that material, and we, the teachers, only push you, guide and support you, of course, not without this. Therefore, all other technical nuances not covered in this lecture, you will have to study yourself. And then at the exam, I will ask you a simple question: what is the difference between the concept of "external pipe diameter" and the concept of "internal pipe diameter". Whoever answers will go home with an A.

And besides, in one lecture it is impossible to highlight all the nuances associated with such a large-scale topic. For a more detailed analysis, it is necessary to devote at least a separate lecture to each engineering communication. And as a maximum - a course of lectures. Because even such seemingly simple concepts as "pipe" or "well" require a fairly scrupulous study.

Let's think about this better. And can a person live without utilities at all? .. I can answer my own question in the affirmative: it can. Very much. I checked it on myself. Instead of running water, you can use a regular village well. Water from a well heals all diseases, water from a mains supply - rather the opposite. Instead of today's gas or electric stove, a Russian stove has been used since time immemorial in Russia. The stove is a great invention, it has not yet been invented better. The most delicious and digestible food is from the oven. And baked milk from it is generally something unforgettable. Clay jug, brown film on top, aroma for the whole hut ... For 7-8 hours the milk languishes - and you can drink.

In addition, the Russian stove plays the role of a heating element, so batteries and heating mains are completely unnecessary in the countryside. And if someone has the opportunity to equip a classic fireplace in the living room, then ... In a word, a stove and a fireplace replace a lot in our life. And they replace it in a more complete way.

What can replace a light bulb? .. A big candle, of course. What else? .. As it is sung in one unobtrusive song "Put a candle on the table, put a candle on the table, as it was once upon a time."

The sewerage system in the village is a wooden "dry closet". A very romantic invention. You especially feel this romance when you go out into the yard on a warm, starry summer night ... dogs bark in the distance, frogs mysteriously purr on the pond ...

Telephone, TV, Internet are categories of life that can also be replaced. Well, nothing, before we lived without this newfangled luxury, and life was much more interesting than now. Everything was in short supply, everything was forbidden, life seemed an endless mystery. We read exciting books and interesting newspapers, solved crosswords, played guitars and button accordions, sent each other real letters in envelopes with stamps, went to dances and to the circus - and were happy. This is what I wish to all young people who have entered adulthood in the 21st century.

Engineering networks of cities are designed as an integrated system that unites all overground, surface and underground networks, taking into account their development for the billing period. Underground networks are laid mainly under streets and roads, for which they provide places for laying networks in their transverse profiles: cable networks (power, communications, signaling and dispatching networks) are placed on the strip between the red line and the building line; under the sidewalks there are heating networks or pass-through collectors; on the dividing lines - water supply, gas pipeline and household sewerage. If the width of the streets is more than 60 m within the red line, the water supply and sewerage networks are laid on both sides of the streets. When reconstructing carriageways of streets and roads, usually the networks located under them are transferred under the dividing strips and sidewalks. An exception may be gravity-flowing networks of household and storm sewers.

When designing the main routes of underground utilities, they are made rectilinear, parallel to the axis or red line of the street, placed on one side of the street without crossing it. Underground networks should not be located one above the other, with the exception of sections at intersections and branches, where intersections are provided in accordance with the norms at different levels. The most expedient is the location of underground utilities under the green zone of the street and sidewalks, but it is often necessary to use also part of the space under the carriageway of the streets.

In case of reconstruction and expansion of communications in the integrated design, reserve sections are provided in the underground space of streets.

10.2. Principles of placement and methods of laying underground utilities

The placement of distribution routes of underground networks on the territory of the microdistrict and residential quarters depends on the general planning solution and the terrain.

Distances from underground networks to buildings, structures, green spaces and to neighboring underground networks are regulated. All trenches of underground networks are located outside the zone of pressure in the soil from buildings, which helps to preserve the integrity of the base of the building's foundations, to protect it from erosion (Figure 10.1). Compliance with the standard distances, in addition, prevents the possibility of damage, and, if necessary, provides conditions for repair. The minimum values ​​of these distances are given in SNiP 2.07.01-89 *.

Laying underground engineering networks can be done in three ways (Figure 10.2): 1) in a separate way, when each communication is laid in the ground separately in compliance with the appropriate sanitary-technological and construction conditions for placement, regardless of the methods and timing of the arrangement of the remaining communications; 2) in a combined way, when communications for various purposes are laid simultaneously in the same trench; 3) in a combined collector, when networks for various purposes are co-located in one collector.

The last two methods are used to lay engineering networks of the same direction. In the case when the network of underground communications

tions are so developed that there is not enough space in the trenches, the third method is used.

"The separate method of laying underground networks has major drawbacks, since significant excavation work when opening one communication can contribute to damage

others due to changes in pressure and soil cohesion. In addition, the construction time increases due to the fact that communications are laid consistently.

With the combined method, pipelines are laid simultaneously, and cables, pipelines and non-passable channels can be located in one trench. This method is applicable when reconstructing streets or creating new buildings, since the volume of earthworks is reduced by 20 ... 40%.

Laying networks in a combined manifold reduces the volume earthworks and construction time. This method greatly facilitates operation, simplifies the repair and replacement of communications without excavation. When laying networks in a combined collector, it is possible to arrange separate communications even after the end of the zero construction cycle. The collector can accommodate heating networks with a diameter of 500 to 900 mm running in one direction, water conduits with a diameter of up to 500 mm, more than ten communication cables and power cables with a voltage of up to 10 kV. Allowed to be located in common collectors of air ducts, pressure pipelines of water supply, sewerage. Joint laying of gas pipelines and pipelines with combustible and flammable substances is not allowed.

Collectors are distinguished by design, size, cross-sectional shape. The collector is a walk-through (human-sized), semi-walk-through (below 1.5 m) or no-pass gallery made of prefabricated reinforced concrete structures.

Pass-through collectors must be equipped with supply natural and mechanical ventilation to ensure the internal temperature within 5 ... 30 ° С and at least three times air exchange in 1 hour, as well as electric lighting and pumping devices.

Shallow and deep networks. Underground communications of the city are the most important element of engineering equipment and landscaping, meeting the necessary sanitary and hygienic requirements and providing a high level of amenities for the population. Underground communications include networks of hot and cold water supply, gasification, power supply, signaling for special purposes, telephony, radio broadcasting, telegraph, sewerage, drainage (storm sewer), drainage, as well as new types of development (pneumatic mail, garbage disposal), etc. ...

Urban underground communications are constantly evolving, representing a complex and important part of the urban "organism". Underground networks are subdivided into transit, trunk and distribution (distribution) networks.

TO transit include those underground communications that pass through the city, but are not used in the city, for example

measures a gas pipeline, an oil pipeline running from a field through a given city.

TO mainline refers to the main networks of the city, through which the main types of media in the city are supplied or removed, designed for a large number of consumers. They are usually located in the direction of the main transport routes of the city.

TO distributive(distribution) networks include those communications that branch off from the main ones and are brought directly to houses.

<* Подземные сети имеют разную глубину заложения. Сети мел­кого заложения располагают в зоне промерзания грунта, а сети глубокого заложения - ниже зоны промерзания. Глубину промер­зания грунта определяют по СНиП 23-01-99. Для Москвы, напри­мер, она составляет 140 см.

TO shallow networks include networks, the operation of which allows significant cooling: electric low-current and power cables, telephone and telegraph cables, signaling, gas pipelines, heating networks. TO networks of deeplaying down include underground utilities that cannot be overcooled: water supply, sewerage, drain. For underground networks, steel, concrete, reinforced concrete, asbestos-cement, ceramic and polyethylene pipelines can be used.

Water supply. One of the necessary conditions for urban improvement is water supply. The water supply system takes into account the number of consumers and the rate of water consumption. There are standards for all categories of consumers. The population needs water to meet physiological needs: cooking, maintaining hygiene, household activities. The rate of water consumption by one person per day fluctuates depending on the degree of improvement of the city. For the population of large cities, provided with cold and hot water supply, the rate of water consumption per person. is about 400 l / day. This rate includes water consumption for the needs of public utilities (baths, hairdressing salons, laundries, catering establishments, etc.). Another consumer of water is industrial enterprises, in almost all of which the technological process is associated with the consumption of a large amount of water.

The city also takes into account the consumption of water for fire extinguishing, watering green spaces and, depending on climatic conditions, for watering the urban area.

Depending on the amount of water supplied, a water supply system is selected. They can represent two or more parallel strands. Water comes to consumers from a water supply source.

zheniya (rivers, underground waters, seas) through treatment facilities, where it is filtered, discolored, disinfected with chlorine, ozone, hydrogen or ultraviolet rays, desalinated and settled.

Pipelines are made of steel, cast iron, reinforced concrete and plastic, from polyvinyl chloride and polyethylene.

When designing water supply networks, it is very important to provide for the preservation of the required water temperature in the pipes. Therefore, it should not be excessively cooled and heated. Therefore, it is accepted that water supply networks, as a rule, are laid underground. But with a technological and feasibility study, other types of placement are also allowed.

To exclude hypothermia and freezing of water pipes, the depth of their laying, counting to the bottom, should be 0.5 m more than the calculated depth of penetration into the soil of zero temperature, i.e., the depth of freezing of the soil. To prevent water heating in the summer season, the depth of pipelines should be taken at least 0.5 m, counting to the top of the pipes. The depth of the production pipelines must be checked from the condition of preventing water heating only if it is unacceptable for technological reasons.

Water supply networks are made circular and in rare cases dead-end, since they are less convenient for repair and operation, and water can stagnate in them.

The diameter of the pipes is taken by calculation in accordance with the instructions of SNiP 2.04.02-84. The diameter of the water supply pipes, combined with the fire-prevention one, for urban areas is not less than 100 and not more than 1000 mm. The water supply network maintains a free head of at least 10 m of water column, which makes it possible to use the water supply network to extinguish fires. For this purpose, along the entire length of the water supply network, after 150 m, special devices are installed for connecting fire hoses - hydrants. The norms stipulate that for external fire extinguishing, a water flow rate of 100 l / s is required.

Thanks to the free head in the water supply network, at least 10 m of buildings with a small number of storeys are provided with water without an additional pump. In high-rise buildings, additional pressure is created by local pumps.

The location of the water supply lines on the master plans, as well as the minimum distances in the plan and at the intersection from the outer surface of pipes to structures and utilities should be taken in accordance with SNiP 2.07.01-89 *.

For proper operation and repair, water supply wells are arranged on water supply networks. They are made from precast concrete or local materials. When the groundwater level is above the bottom of the well,

cabins waterproofing its bottom and walls 0.5 m above the groundwater level.

Inspection wells are arranged in all places where the direction, diameter or slope change, at the points of connection of the side lines. In addition, inspection wells are built at certain distances on all pipelines to monitor their condition and timely cleaning. Currently, wells are unified and subdivided into small - for pipes with a diameter of up to 600 mm and large - over 600 mm. In terms of shape, typical wells are round, rectangular, trapezoidal. The most economical in terms of concrete consumption and the easiest to manufacture are round wells.

Water pipes for irrigation, filling outdoor pools, and functioning of fountains operate only in summer, so they are allowed to be laid at a depth of 0.5 m.

Hot water supply is arranged in cities with a high level of amenities. Hot water is supplied to residential buildings by quarterly centralized hot water supply systems from separate central heating points (DTP), which, as a rule, are located in the center of the serviced area. Thermal power TSC are chosen taking into account the prospective construction.

The hot water supply network is calculated with a centralized water supply system for two operating modes: hot water withdrawal mode during the hours of maximum water consumption; water circulation mode during the hours of minimum draw-off.

For hot water supply networks, water and gas supply galvanized pipes are used, connected by thread or welding. The slope of pipelines is taken at least 0.002. The pipes are insulated to reduce heat loss. The laying of hot water pipes is allowed in a channelless method (directly in the ground) or in channels together with heating networks. ;. Sewerage. Sewerage is a necessary system for the purification of settlements from wastewater. Its task is to remove water contaminated as a result of human household activities and the work of industrial enterprises that use water in the technological process.

Sewerage can be combined and separate. The common sewerage system carries out the drainage of storm wastewater by one system of pipelines, which comes after rain from urban areas through storm inlet grilles, and household and fecal wastewater coming from residential buildings. With a separate sewerage system, two independent wastewater drainage systems are used: storm sewerage (drainage), household and fecal. Wastewater from industrial enterprises is discharged by a separate system to render them harmless from specific

5 Nikolaevskaya \ 2.U

pollution. Currently, a separate sewerage system is most applicable.

The sewerage system not only removes waste water from buildings, but also purifies them to such an extent that when they are discharged into a reservoir, they do not violate its sanitary conditions. For this purpose, sewer networks, pumping stations for pumping, facilities for wastewater treatment and for the release of treated wastewater are used.

The diameters of the sewer pipes of the system depend on the amount of wastewater, which is determined by the degree of improvement, that is, the rate of water consumption, the presence of hot water supply. So, the rate of waste water consumption with centralized hot water supply and the presence of a bath is 400 l / day. for 1 person, and for gas heating installations - 300 l / day.

The sewerage route is selected using a feasibility study of possible options. When several pressure pipelines are laid in parallel, the distance from the outer surfaces of the pipes to structures and utilities should be taken in accordance with SNiP 2.04.03-85 based on the conditions for protecting adjacent pipelines and performing work.

The smallest laying depth is taken in accordance with SNiP 2.04.03-85 for sewer pipes with a diameter of up to 500 mm by 0.3 m, for large diameter pipes - 0.5 m less than the maximum depth of penetration into the ground of zero temperature, but not less than 0, 7 m to the top of the pipe, counting from the planning marks.

Heat supply. Thermal energy is required for the operation of industrial enterprises, heating, ventilation, air conditioning and centralized hot water supply of buildings. Housing and communal services use about 25% of all thermal energy consumed by the city.

Heat supply to cities can be carried out in two ways: centralized (receiving heat energy from CHP plants and powerful boiler houses) and decentralized (from local heat sources).

In accordance with SNiP 2.07.01-89 *, heat supply to cities and residential areas with buildings with a height of more than two floors must be centralized. With district heating, one boiler plant supplies heat to a group of houses, a block or a city district, as well as industrial enterprises. Boiler houses, depending on the purpose, are divided into power, production and heating. Heating boiler houses provide heat for the needs of heating, ventilation and hot water supply of residential and public buildings, and, depending on the production capacity, there are individual and group ones. Group groups are conditionally subdivided, depending on the size of the serviced area, into quarter and district.

To transport heat to consumers, pipelines are used - heating networks, which can transfer heat using water and steam, and, depending on the heat carrier, they can respectively be water and steam.

Currently, heating networks can transfer heat over long distances. Heating networks of different districts of the city are interconnected so that in case of failure of one heat source it could be duplicated by another. This allows uninterrupted supply of heat to all areas of the city and at the same time eliminates the malfunction.

Heating networks that supply heat to industrial enterprises are called industrial, to residential and public buildings - municipal, to enterprises and civil buildings - mixed.

Heating networks are made two- and multi-pipe. The most common is the two-pipe system, in which one pipe is supply ■ and the other is return. In this system, water circulates in a closed circle: having given its heat to the consumer, it returns to the boiler room. In residential areas, two types of water heating systems are used: open and closed. Their difference lies in the fact that with a closed heat supply system, a constant amount of water circulates in the pipelines, and with an open one, part of the water directly from the system is disassembled for the needs of hot water supply. In an open heat supply system, water must be of the same quality as drinking water, and the water supply must be constantly replenished.

Trunk networks are located in the main directions from the heat source and consist of pipes of large diameters - from 400 to 1200 mm. Distribution networks have a diameter of branch pipelines from the main ones from 100 to 300 mm, and the diameter of pipelines leading to consumers - from 50 to 150 mm. d Steam heat supply systems are made one- and two-pipe, while the return of condensate is carried out through a special pipe - a condensate pipeline. Under the action of an initial pressure of 0.6 ... 0.7 MPa, and sometimes 1.3 ... 1.6 MPa, steam moves at a speed of 30 ... 40 m / s. Pipes are used metal and metal-polymer in accordance with SP-41-102-98 and SNiP 2.05.06-85. When choosing a method for laying heat pipelines, the main task is to ensure the durability, reliability and economy of the solution.

Channelless laying heat pipelines are a simple and cheap way of laying, therefore it is the most common. This method has, however, major disadvantages, such as corrosion, difficulty in repair, lack of periodic supervision. In part, these disadvantages are overcome by protecting pipes from external soil influences using an insulating material.

la, cement crust and waterproofing. This method of protection is used in reinforced foam concrete, where the reinforcement is made in the form of a mesh, which gives significant rigidity to pipelines. Heating networks are allowed to be laid in common trenches with water pipes, drains, sewerage and gas pipelines with a pressure of up to 0.3 MPa inclusive.

Laying in impassable channels- the most convenient way of laying heat pipes, which explains its widespread use. The advantage of this method over channelless laying is that the pipeline is protected from fluctuations in pressure in the ground, since it is enclosed in a channel, where it is located on special movable and fixed supports. However, it has a drawback: there is no constant monitoring of the state of the networks, and in the event of an accident, it is required to break some part of the channel in order to find the place of damage. In non-passable channels, heating systems can be located with oil and gas pipelines, compressed air pipelines with a pressure of up to 1.6 MPa and water pipelines.

In through-flow collectors heating networks can be placed together with water pipelines up to 300 mm in diameter, communication cables, power cables up to 10 kV, and in urban collectors - also with compressed air pipelines with a pressure of up to 1.6 MPa and pressure sewage. In intra-quarter collectors, joint laying of water networks with a diameter of not more than 250 mm with natural gas pipelines with a pressure of up to 0.005 MPa and a diameter of up to 150 mm is allowed. When laying a heating network and a water supply system together, in order to avoid heating the latter, it is thermally insulated and placed either in the same row or under heating networks, taking into account the standard depth of laying. Continuous monitoring and control of the state of the networks is carried out in through collectors. The repair of such networks is simplified. On difficult sections, for example, under central highways with a lot of traffic, at the intersection of railways, under buildings, where it is impossible to lay through collectors, and non-through channels cannot be laid due to the limited ability to break them up for repair, use semi-through channels. Although the passage in them is very small (height up to 1.4 m, width 0.4 ... 0.5 m), it is possible to inspect and repair the heating network.

The route of heating networks in cities is laid in the technical strips allocated for engineering networks parallel to the red lines of streets, roads and driveways outside the carriageway and a strip of green spaces, but if justified, it is allowed to locate the heating mains under the carriageway or street sidewalk. Heating systems must not be laid along the edges of terraces, ravines or artificial excavations in case of subsiding soils.

The slope of heating networks, regardless of the direction of movement of the coolant and the method of installation, must be at least 0.002.

1 In SNiP 2.04.07-86 and SNiP 3.05.03-85, special conditions are given for the arrangement of intersections by heating networks of other underground structures.

Gas supply. Thanks to the development of the gas industry in our country, most settlements and cities are supplied with gas. Gas is used in industry and housing and communal services. It is transported through pipelines from fields over long distances and arrives at the consumer in the form of a combustible mixture of hydrocarbon, hydrogen and carbon monoxide. Gas consumption rates depend on the equipment of the apartment, climatic conditions, and the level of development of public services. For example, the gas consumption rate in an apartment with a gas stove and hot water supply is taken as 77 m 3 / year for 1 person, and in an apartment with a gas stove and a gas water heater for hot water supply - 160 m 3 Dod.

The city gas supply system consists of gas pipelines, gas control points and service facilities.

Gas pipelines transporting wet gas are laid below the zone of seasonal soil freezing with slopes of 0.002 towards the condensate collectors. Gas pipelines transporting dried gas, when laid in non-porous soils, may be located in the zone of seasonal soil freezing.

Power supply. The modern city is a complex complex of various consumers of electrical energy. The bulk of electricity is consumed by industry (about 70%).

In recent years, the area of ​​application of electricity for household needs, accounting for an average of 20% of total consumption, has significantly expanded. Depending on the size of the city, climatic conditions, the development of industry in it and many other factors, the share of utilities load and specific power consumption (per 1 inhabitant or per 1 m 2 of living space) can vary within wide limits. For Moscow, for example, the total electrical loads of residential and public buildings in the power supply system of the microdistrict are more than 40 W / m 2 of living space in areas with gas cookers, and in areas with electric cookers - more than 50 ... 55 W / m 2 ...

The transmission of electricity to consumers within residential areas is carried out by underground cable lines, which are laid on the strip between the red line and the building line. Laying of underground power cable lines is carried out, as a rule, in common trenches. In cases of intersections with main routes and railways, with a lack of free space in the cross-section of the street and in some other cases, the laying of power cables is allowed to be carried out in common

collectors, and the power cables must be in the collector above other engineering networks.

Technical operation of the microdistrict equipment. The housing stock is one of the most complex sectors of the municipal economy, requiring further improvement of operation and new forms of management using automation, telemechanics and computer technology.

One of the stages of improving the housing economy is the creation of dispatch systems. With the construction of high-rise buildings with high-speed elevators, automatic smoke removal and fire alarm systems, the saturation of housing with a variety of complex underground engineering equipment to improve operation, the need arose for integrated integrated dispatching systems (ODS) for monitoring and controlling engineering equipment. The ODS can control the operation of all major types of engineering equipment and provides for two-way loudspeaker communication of the dispatcher with passengers in the elevator car, with residents at each entrance of the building, with the technical rooms of the microdistrict. The ODS can control the automatic locking devices (AZU) of entrances, the operation of elevators, emergency lighting of the territory of the DEZ, the temperature of the heat carrier of the central heating station and boiler houses. The ODS system provides for subsystems for monitoring water consumption, gas content, flooding of premises and collectors, etc. The use of ODS will help to timely detect and eliminate malfunctions in underground utilities.

Test questions and tasks

List what engineering communications are being laid in the underground part of the city.

Draw a diagram of the location of the networks in the cross-section of the street, explain the order of the arrangement.

Explain the features of all methods of laying underground utility networks and give their comparative analysis.

What are the design features of the arrangement of networks: water supply, sewerage, heat supply, gas supply, energy supply?

Underground communications of the city are the most important element of engineering equipment and landscaping, meeting the necessary sanitary and hygienic requirements and providing a high level of amenities for the population. Underground communications include networks of hot and cold water supply, gasification, power supply, signaling for special purposes, telephony, radio broadcasting, telegraph, sewerage, drainage (storm sewer), drainage, as well as new types of development (pneumatic mail, garbage disposal), etc. ...

A complex of underground communications in a well-maintained city. Engineering networks of cities are designed as an integrated system that unites all overground, surface and underground networks, taking into account their development for the billing period. Underground networks are laid mainly under streets and roads, for which they provide places for laying networks in their transverse profiles: cable networks are placed on the strip between the red line and the building line; under the sidewalks there are heating networks or pass-through collectors; on the dividing lines - water supply, gas pipeline and household sewerage.

When designing the main routes of underground utilities, they are made rectilinear, parallel to the axis or red line of the street, placed on one side of the street without crossing it. Underground networks should not be located one above the other, with the exception of sections at intersections and branches, where intersections are provided in accordance with the norms at different levels. The most expedient is the location of underground utilities under the green zone of the street and sidewalks, but it is often necessary to use also part of the space under the carriageway of the streets.

Water supply. One of the necessary conditions for urban improvement is water supply. Water consumers: population, industrial enterprises; water is also needed for fire extinguishing, watering green spaces and, depending on climatic conditions, for watering the urban area.

Depending on the amount of water supplied, a water supply system is selected. They can represent two or more parallel strands. Water comes to consumers from a water supply source (rivers, groundwater, sea) through treatment facilities, where it is filtered, discolored, disinfected with chlorine, ozone, hydrogen or ultraviolet rays, desalinated and settled.

To exclude hypothermia and freezing of water pipes, the depth of their laying, counting to the bottom, should be 0.5 m greater than the depth of freezing of the soil.

Sewerage. Sewerage is a necessary system for the purification of settlements from wastewater. Its task is to remove water contaminated as a result of human household activities and the work of industrial enterprises that use water in the technological process.

Sewerage can be combined and separate. The general-purpose sewerage system carries out the drainage of storm wastewater and household wastewater with one system of pipelines. With a separate sewerage system, two independent wastewater disposal systems are used. Wastewater from industrial enterprises is discharged by a separate system to neutralize them from specific contaminants. Currently, a separate sewerage system is most applicable.

Heat supply. Thermal energy is required for the operation of industrial enterprises, heating, ventilation, air conditioning and centralized hot water supply of buildings. Housing and communal services use about 25% of all thermal energy consumed by the city.

Heat supply to cities can be carried out in two ways: centralized (receiving heat energy from CHP plants and powerful boiler houses) and decentralized (from local heat sources).

To transport heat to consumers, pipelines are used - heating networks, which can transfer heat using water and steam, and, depending on the heat carrier, they can respectively be water and steam. Heating networks of different districts of the city are interconnected so that in case of failure of one heat source it can be duplicated by another.

Gas supply. Thanks to the development of the gas industry in our country, most settlements and cities are supplied with gas. Gas is used in industry and housing and communal services. It is transported through pipelines from fields over long distances and arrives at the consumer in the form of a combustible mixture of hydrocarbon, hydrogen and carbon monoxide.

Power supply. The modern city is a complex complex of various consumers of electrical energy. The bulk of electricity is consumed by industry (about 70%).

The transmission of electricity to consumers within residential areas is carried out by underground cable lines, which are laid on the strip between the red line and the building line. Laying of underground power cable lines is carried out, as a rule, in common trenches. In cases of intersections with main routes and railways, with a lack of free space in the cross-section of the street and in some other cases, the laying of power cables is allowed in common collectors, and the power cables must be located in the collector above other engineering networks.

15. Vertical layout of the territory.

When implementing vertical planning, environmental requirements are taken into account. It is advisable, if possible, to preserve the natural topography, soil cover, vegetation, in every possible way to reduce the volume of earthworks with unbalanced volumes of excavations and embankments.

Neighborhood plots should be located at elevations higher than the red lines of the streets framing them, so that rainwater from residential areas is directed to water intakes on the streets. The design surfaces of the territories of microdistricts can be one-, two-, four-slope and mixed type with different intersections of slopes. Removal of rainwater from courtyards and gardens of microdistricts is carried out by trays along the driveways, along which they are directed to water intakes in the streets.

The layer of fertile soil removed during vertical planning should be stored, protected from erosion and pollution, and then used for landscaping the territory of a residential area.

In practice, the following vertical planning methods are most often used:

a) method of profiles;

b) the method of design (red) contours;

c) the method of profiles and design contours (combined method).

For drawing up schemes for the vertical planning of residential areas, the method of design red contours is most widely used. On the plan of the existing surface of the earth with black horizontals, red horizontals are applied, reflecting the projected relief, as well as the placement of buildings, streets, driveways and other elements of the master plan. Comparison of the marks of the red and black contours allows you to identify the locations of shooting and backfilling of soil and the amount of earthwork. At the corners and at the entrances to buildings, red (in the numerator) and black (in the denominator) marks are set and then the floor mark of the first floor is set in accordance with the structure of the building. In residential and public buildings, the excess of the floor of the first floor above the ground mark at the entrance is taken as 0.50-1.50 m, for shops - 0.15-0.60 m.

To protect the banks of reservoirs from erosion, embankments with retaining walls of different types are arranged in cities: vertical, inclined and mixed. In small populated areas along the shores of reservoirs, slopes are made, reinforced with matting, facing, slabs. The greatest costs are required for the strengthening of sea shores and the construction of sea embankments with wave walls.

The fight against the growth of ravines is carried out by streamlining the drains, full or partial backfilling, landscaping and terracing of slopes. Landscaped ravines are used for placing gardens, parks, recreation areas, and in some cases for laying streets.

Among the violations of territories arising under the influence of human activity include dumps of mine rocks, dumps of slag, ash, worked out pits, excavations, deflections of the earth's surface. Dumps of all types, after leveling, compaction and covering with a layer of fertile soil, are used for landscaping, sports grounds, recreation areas, and, if the necessary bearing capacity is provided, for placing some buildings. Excavations, quarries, areas of sinkholes are filled up, the surface is cultivated, and also used to locate gardens and playgrounds.

When designing streets, one should avoid deep cuts and, especially, large embankments.

When designing streets, especially new ones, one should avoid the device of a longitudinal profile with sharp fractures, which are always unfavorable in terms of visibility for the driver of transport and the visual perception of the street. The most favorable is the slightly concave longitudinal profile of the street.

About 70% of the population of Russia now lives in cities with more than 100 thousand people. At the same time, the tendency of the consistent inclusion of rural settlements in the urban line is clearly progressing.

A significant factor in ensuring social progress is reliably functioning underground communications of the city, which provide its population with communications and the Internet, water, electricity, gas, heating, and sewerage.

They are extremely saturated and branched. Their characteristic structural components are manifolds, pipelines and low and high voltage cables. In addition to settlements, enterprises and organizations also have their own engineering support structures.

It is noteworthy that the book value of the communication facilities sometimes exceeds a third of all overground buildings. Its development and systematic improvement can stimulate or, conversely, restrain the development of megalopolises.

The existing urban development, for its part, also affects the acceptable ways of building engineering networks and communications. Nowadays, most of them are laid in a closed way without preliminary trenching.

Definition and concept of communications (PC)

Thus, the underground functionally provide the population with electricity and heat supply, water supply and drainage, communications, signaling and the Internet. Their main veins are most often placed under street and road routes.

Thus, the structural elements of the PC are:

• Steel, ceramic, concrete, polyethylene, asbestos-cement pipelines. They are laid, guided by hydraulic calculations. They are pressure (water -, gas -, oil pipelines) and gravity (drainage, sewerage, water drainage).
• High and low voltage power supply cable communications.
• Cable communications, signaling.

Classification of underground utilities

According to the method of providing services, PCs are subdivided into transit, trunk, and distribution. The first pass through the city to other settlements (gas and oil pipelines). The second are the main supply channels for the entire city or metropolitan areas, while the third directly bring services to homes.

By depth, the networks are subdivided into those laid down to the boundary of freezing of the soil and below it (SNiP 2.05.02.85).

In turn, water and heat supply schemes are subdivided into those with forced and natural circulation, with lower and upper distribution, with associated water movement and dead-end, two- and one-pipe.

Underground power supply and communication schemes consist of cable shafts, switchgears and substations.

PC design

The underground utilities plan is an important and obligatory component of any complex construction project. Typically, communications in order to avoid excessive mechanical stress are located outside the areas of pressure on the ground of buildings.

In the plan of the PC, the ways of laying are necessarily reflected. Let's consider their options.

With a separate method, one or another communication is supplied to the construction object individually. The timing of its construction is also individual, independent of the laying of other PCs. This is an outdated method, since in the conditions of saturated urban development, earthworks to repair one communication can damage another. It is used nowadays in a narrowly targeted manner, in cases of revision of existing PCs.

The combined method involves the location of several communications at the same time in one trench. It is used in conditions of limited funding and a critical need for specific PCs.

The most common and promising in terms of mass development is the collector method (CM), in which various PCs are placed in a standard common collector. This method greatly simplifies the repair and operation of a PC. However, the collection method cannot be called universal. It is impossible to combine sewerage, pressure water supply in one collector with other communications.

The collector itself is a concrete box. It can be of different heights. Height and half-height (up to one and a half meters) requires ventilation. In the box itself, a temperature regime of 5 to 30 degrees Celsius is observed.

Security requirement in building a PC

Errors in the construction of underground communications lead to accidents, injuries, fires, breakdowns of devices and equipment powered from them (STO 36554501-008-2007). During the construction of the PK, the geological and hydrogeological properties of soils must be taken into account, as well as the possible seasonal dynamics of their change must be predicted.

Electrical equipment used for laying trenches and pipes must be explosion-proof. Tunnels and mines in the areas of electric welding works for the time of their execution are obligatorily provided with a local hood.

The stay of workers - laying in pipelines is permissible if the diameter of the structure exceeds 1.2 meters, and the length is not more than 40 m. For a pipe length of more than 10 m, forced ventilation is provided from 10 cubic meters / hour.

In terms of time, the stay of workers in the pipeline is limited to one hour with breaks of 0.5 hours.

Typical PC construction

Modern construction of underground communications is carried out in accordance with the location of city streets, terrain, large users of services. The cross-section of streets that are being built or renovated is taken into account.

In this case, cable networks are laid along roads and streets. Moreover, main communications run along the main streets, while residential neighborhoods are equipped with receiving and distributing PCs powered by them.

Pass-through collectors and heat pipes are located under the sidewalks. At the borders of the sidewalk and streets, they will equip a sewerage system, a gas pipeline, and a water supply.

Modern PC Laying Methods

The laying of underground utilities is now more and more often performed trenchless. This method allows you to bend around terrain obstacles with high precision and time efficiency.

The first trenchless method begins with pilot drilling using a drill rod to bypass obstacles along the bottom edge. The drilled hole is then enlarged with a reamer.

The second is based on the use of a self-propelled tunneling mechanism called a shield. The latter is placed in a specially opened starting pit, and then put into action. He punches a channel in the ground up to the finishing pit, which was also previously opened for him.

The third is also performed between the channels, but at a smaller distance and with the help of a pipe horizontally driven by a pneumatic punch.

PCs often form an intersection with each other, underground utilities in this case are separated from each other vertically according to the requirements of SNiP II-89-80, see table 1.

Table 1. Standard distances during PC construction to roads, building foundations, etc.

PC detection problem

Modern urban construction, carried out in areas with already existing buildings, presupposes a preliminary search for underground utilities. It is carried out using specialized equipment. The most often used is a locator of underground utilities. He determines the configuration of the PC, the depth of location and even the location of damage, the location of its individual veins, hidden communications.

Neglecting such a search is fraught with PC crashes. The desire of individual construction organizations to save money by not paying certified firms for the services of determining third-party communications in the area of ​​earth construction often leads to accidents and, as a result, to a forced increase in the costs of eliminating them.

About PC shooting

Survey of underground utilities is advisable if there is no primary executive documentation for them, (i.e., documentation that is produced directly in the process of their construction). It is important for tying PCs to new infrastructure.

Such jobs are most in demand in large cities, where their density is highest. Survey of underground communications is a core area of ​​work of specialized electrical measuring laboratories that exist at organizations involved in pipe and cable laying.

The proper level of their implementation allows you to determine not only the direction and depth of the entire communication route as a whole, but also each of its segments separately.

Its essential elements are essential functional parts of each type of PC:

• pipe and water supply (valves, hydrants, angles of rotation, plungers, pipe diameter);
• cable networks (transformers, switchgears);
• sewerage systems (pumping stations, overflow and inspection wells);
• gutters (overflow and water outlets);
• drains (perforated pipes);
• gas pipelines (main and distribution sections, shut-off valves, pressure regulators, condensate collectors);
• heat supply networks (compensators, chambers with valves, condensation devices).

High accuracy of PC shooting is ensured by the competent use of high-precision equipment for PC diagnostics, specialized software,

A locator of underground utilities, a cable detector, a metal detector, a multiscanner allow diagnosing a PC with a high accuracy of identifying all their structural elements. In passive shooting mode, it is possible with sufficient accuracy to determine communications located at a depth of 2.5 m.

However, the rich structure of communications, especially if they are located from each other, as well as their significant depth (up to 10 m), significantly complicates a more detailed search for underground communications. In this case, the active detection mode is practiced. Around the investigated cable or pipe, an electromagnetic field is initiated with a special generator, and by measuring it, the required characteristics of the PC are determined.

PC repair

It is obvious that the existing underground communications are subject to major repairs and reconstruction only by organizations and enterprises that have the appropriate permits, within the time frame approved in the consolidated plans of municipal communal management structures. Every year, by November 30, the operating enterprises submit their plans for such work to the city administration of housing and communal services for coordination and accounting.

If in the course of such work it is necessary to violate the integrity of the lawns, to remove the roadway, then permits from the local government are required. When redeveloping existing PCs in connection with the construction of new facilities, their re-equipment is carried out by the general contractor according to the project. Each specific PC repair project must be agreed by the general contractor with all business entities whose underground communications are located in the work area.

To obtain it, the customer submits the following package of documentation:

• a letter agreed with the municipal authorities;
• project of work and plan of the PC route;
• guarantee of restoration of the road surface;
• confirmation of the availability of equipment and materials necessary for the repair;
• order to appoint a person responsible for the repair.

The customer also pays for the lease of the repair area, after which he receives a permit.

If, while performing work, the contractor discovers a PC that is not specified in the project, he is obliged to stop work and notify the customer. He, in turn, calls the employees of the project company, who draw up an act on this matter and formulate an official decision.

In case of damage to the PC, the architecture management, with the participation of all interested parties, draws up an act and makes a decision on compensation for the damage. The culprit is determined, and the terms of elimination are set.

PC service

PC maintenance is carried out for the purpose of safe and uninterrupted supply of the population and business with electricity, water, gas, communication services, drainage, sewerage, etc. This task is complicated by the visual inaccessibility of communication routes. Thus, the operation of a PC is reduced to their preventive maintenance and current repair.

The goal of preventive maintenance is to identify possible damage resulting in leaks and other supply disruptions. The first part of it is the inspection and measurement of basic indicators directly on the external elements of communications (transformers, switchgears, inspection chambers, condensation devices). However, the basic indicators are the pressure of water and gas, the voltage of electricity. The frequency of the inspection is determined by the organizations that supply utility services to consumers, it is finally approved by their higher management bodies.

Description of one of the types of service

For the main gas pipeline, route maps are created with hydraulic locks and condensate traps applied to them. In the latter, condensate is pumped out using motor pumps. Only certified specialists are allowed to perform such work. Safety measures prohibit the use of open fire and smoking is strictly prohibited.

To find out the operating modes of gas pipelines at least twice during the period of maximum winter and minimum summer load, the pressure in them is measured.

The tightness of these communications is carried out by periodic drilling and casing inspections. For this purpose, a well with a diameter of 20-30 cm is drilled behind each joint of the gas pipeline. The drill is immersed into the depth at a distance of 20 cm, not reaching the gas pipeline. Next, the presence of gas in these wells is checked.

If the soils in which the gas pipelines are laid have increased corrosiveness, then the integrity of the structures is checked at least once every 2 years, with neutral soils, once every 5 years.

Thus, the areas with the highest pressure drops are determined. Most often, the reason for their formation is the sagging of the gas pipeline caused by the violation of the uniformity of the soil. Therefore, simultaneously with the repair of the integrity of the pipe, a thorough tamping of their soil bed is carried out.

PC organizations (enterprises)

The organization's underground communications are designed in a comprehensive manner as part of a single general project together with buildings and structures. PCs are placed in technical strips optimized in terms of area.

Directly on the territories of the enterprises themselves, only overground and ground communications are used.

The pre-factory communications are laid underground. They are housed together in common tunnels. The length of the PCs of the leading industrial enterprises is up to several tens of kilometers. Labor intensity of laying various communications (in percent) is: sewerage - 65%; water supply - 20%; heat pipelines - 7%; gas pipelines - 3.5%, electric and communication cables - 3%; technological pipelines - 1.5%.

Technological pipelines can be placed together with a gas pipeline, a heat pipeline, while it is prohibited to place pipelines with explosive and flammable liquids.

Conclusion

The problem of replacing underground communications is now becoming very urgent. Its root cause lies in the systemic shortcomings of the state financing mechanism based on the deliberately failed residual principle. Thus, in fact, the objective reality is neglected: the fact that each project laying of underground utilities presupposes specific terms for their replacement, in accordance with the materials of their manufacture and the conditions of their occurrence in the ground.

PC replacement should be planned within the framework of state economic policy. Unfortunately, the inconsistent economic function of the state actually prevents the creation of full-fledged and effective funds for regular capital investment.

In this regard, there is a positive world experience. An example to follow is the Norwegian PC system, which is clearly regulated by the direction of the country's budget to the observance of the relevant state standards.

We constantly observe a vicious closed cycle: how, in the absence of such an established economic mechanism, the managing monopoly organizations now and then initiate an increase in the already inflated tariffs for utilities, motivating this by 90% outdated PCs.