How deep to bury the storm pipe. Do I need to adhere to SNiP when building a storm sewer? The need to create security zones

03.03.2020

The construction of communications brings real comfort to country life, but their open location does not in the best way reflected in the aesthetic component of the site. It is a completely different matter if the sewer pipeline is buried in the ground: it is not visible, the highway does not interfere with movement.

However, for the underground device of the system, compliance with the rules and regulations is necessary. They should be studied, right?

The fundamental laws and subtle nuances according to which sewer pipes are laid in the ground are presented on our website. Focusing on the information we offer, you will build a trouble-free external sewer system.

A pipeline built in accordance with our advice will work perfectly at any time of the year. The article brought to your attention scrupulously outlines the technology for constructing the underground part of the sewer system.

The material describes the nuances of design and laying details. Recommendations are given on the implementation of preventive measures and compliance with the rules for the operation of sewage. To simplify the perception, the information is supplemented with photo images and video instructions.

Today, almost every household has necessary set amenities for a comfortable stay: washbasin, sink, toilet, shower or full bath, washing machine and other benefits of civilization. Many houses are equipped with not one, but several bathrooms and bathrooms.

All this economy full-fledged work produces a large amount of waste and sewage per day. According to the standards, the amount of liquid waste per day per person is from 5.4 to 9.5 liters, which must merge somewhere.

As a rule, country houses where people live permanently have many different plumbing devices, which makes it necessary to equip an autonomous sewer system.

Therefore, the drainage system is an obligatory part of the engineering communications of an individual house. It consists of an outlet from a residential building and an external sewer network laid on the site.

Many owners of private houses, paying special attention to the intra-house system, for some reason do not always properly treat the arrangement of external networks.

Indeed, the process of laying the pipeline seems simple, it is enough to dig a trench, dock the pipes with each other, the house system and the collector, and then cover everything with earth.

But this is only at first glance. In fact, in this, as well as in any other work, there are many nuances that must be taken into account. Failure to comply with technological standards and improper laying of the pipeline can lead to silting and other considerable problems in the future.

If the site has a natural slope that exceeds the recommended standards, it is possible to lay a sewer with several vertical transitions. In this case, on the horizontal sections of the pipeline, it is necessary to comply with the regulatory indicators.

Actions in case of sewer freezing

If you have not insulated the sewer pipes, or you have not insulated them enough, and they are frozen, first of all, you need to determine the damaged section of the pipeline in order to choose a method for solving the problem. Metal pipes can be heated with a blowtorch.

If the pipeline is made of plastic, open flames cannot be used. You can pour hot water into the sewer, in which you first dissolve salt (2 kg per 10 liters of water). You can direct the steam jet or hot water to the revision closest to the frozen area.

If the damaged pipe is in the middle of the line, you can use a steam generator to warm up the soil. However, this process can take quite a long time. It is best to prevent the system from freezing, and when laying pipes, carry out their high-quality thermal insulation.

Conclusions and useful video on the topic

This video explains the installation process in great detail. outdoor sewerage, as well as the normative indicators that must be followed during installation:

This video shows how sewer pipes are laid in the ground:

Despite the apparent simplicity, the work of laying sewer pipes requires a competent approach and knowledge of the regulatory rules for laying. Only if the necessary indicators are met and correct execution works, you can equip a really efficient and durable sewer system.

Trying to lay sewer pipes yourself? Or maybe you don't agree with what is said? We are waiting for your comments and questions - the contact form is located below.

This type of sewage is a complex engineering device, so an accurate calculation storm sewer in its design is of great importance. In general, the installation of such a system requires an integrated approach; certain technical requirements must be observed in the process. The project must be approved by the Sanitary and Epidemiological Service, by the bodies for the protection of fish stocks and the protection and regulation of waters.

Stormwater design

Stages of drafting a project

The design process consists of the following steps:

Storm sewer project: its development in relation to a specific site.
Coordination this project at all necessary levels.
Direct implementation of the installation of a storm system on the site.

The first stage of the design is the development of project documentation. The basis for such work is the terms of reference, diagrams, drawings. When developing, it is necessary to rely on regulatory documents: SNiPs, SanPiNs, GOST 3634-99 and some others.

The main document at this stage is the terms of reference. It is compiled based on the wishes and requirements of the customer, filled in in accordance with GOST 19.201-78. The terms of reference reflect the terms of the work, the purpose of the device, technical and economic requirements, the control procedure. Applications are allowed if necessary.

Calculation of parameters included in the project

The methodology for calculating storm sewers includes the following key points:

determining what type of sewerage should be used: internal or external;
finding out the location of storm sewer wells, what will be their number;
calculation of the required pipe length;
selection of signaling devices, sensors and materials.

The decision is influenced by such parameters as the catchment area, the presence of water bodies (natural or artificial) in the immediate vicinity, the maximum amount of precipitation and the average rate of their precipitation, the speed with which runoff water moves and other factors that can characterize this object.

The calculation of water consumption and the cross section of storm pipes are described in the article "Calculation of storm sewers".

In order to have an idea of the monetary investments invested in the organization of this system, an estimate is made for storm sewers. It includes the cost of all components, namely:

Point type water collectors.
Water pipe systems.
Various purposes of storm sewer wells.
Effluent filters.

If necessary, the estimate can be supplemented with other elements at the request of the customer.

One of the important parts that the storm sewer scheme includes is a well. Depending on its type, it can collect wastewater, distribute it for treatment, water sampling, sediment erosion, flow measurement, inspection and maintenance of underground utilities.

The process of designing a rainwater sewer system has its own characteristics, which include:

trace;
calculation of hydraulic parameters;
designing system elements, their linking.

Tracing is necessary in order to collect rain and melt water from a specific area and divert it to the place of release or treatment.

At what depth should storm sewers be placed

Despite the fact that this issue is being vigorously discussed at construction forums, SNiP 2.04.03-85 gives a clear answer to it, which states that the depth based on the experience of operating networks in this region is taken as the smallest depth.

To determine the minimum depth, thermotechnical and statistical calculations are carried out.

For practical purposes, the depth of the storm sewer is such a value that it is possible to minimize the amount of work performed when digging a trench, as well as to ensure the pipes are safe from external damage and prevent freezing of sewage in the pipeline.

Storm slope

With an inner diameter of pipes of 0.2 meters, the slope should be 0.007, and if inner diameter is 0.15 meters - a slope of at least 0.008. If for objective reasons it is impossible to make such a slope, the standard is reduced to 0.007 for 150 mm pipes and to 0.005 for 200 mm pipes.

For drainage open type the values of the minimum slope for storm pipes are:

for a drainage ditch - 0.003;
tray of the roadway, the surface of which is asphalt concrete - 0.003;
tray of the roadway, which is covered with crushed stone or paving stones - 0.004;
when the cobblestone tray of the roadway is covered - 0.005;
separately located tray - 0.005.

Based on these numbers, you can see that the slope depends on the roughness: the larger it is, the greater the slope required. The diameter of the pipes also matters: the larger it is, the less slope is required to ensure the required flow rate.

The numbers given in normative documents, are the result of practical research in the construction a large number buildings, however, are not dogma for the developer. They provide the information needed to create reliable system. If you adhere to these standards, then with proper operation of storm sewers, it will serve uninterruptedly for many years.

canalizaciya-prosto.ru

Reasons for submerging the highway underground

The simplest laying of the collector is to place it on the surface of the site. This is how it is done in some parts of the country. For example, in areas of northern climate zone, installation of water supply and sanitation communications is carried out on top of the ground. Such a laying system is dictated by local conditions - climate, the presence of permafrost, convenient access during repair work and economic feasibility. Therefore, the problem - what should be the depth of the sewer pipe in a private house, is absent.

However, in places with a harsh climate, a tenth of the population lives. Not all of them live in the private sector. The rest of the regions are dominated by temperate climate, the earth does not remain frozen and thaws in the warm season. Hence, with the construction of sewerage in country house, the main way is to lay the highway underground. Reasons for using this method:

requirements of regulatory documents;
protection against mechanical damage;
defrosting protection;
lower probability of contamination of the surface layer of the earth with biological and chemical components;
saving priceless square meters land area on your own property.

The idea that sewer pipes should be hidden underground is the voice of common sense and a competent technical solution. It remains the case for small things: to determine what is the required depth of laying sewer pipes in a private house.

The composition of the external communication system

Before deciding how deep to dig sewer pipe, it is required to determine the design of the external drainage system.

On the suburban area a device is being laid for the discharge of domestic wastewater and the removal of storm drains. In the latter case, special events are carried out with a significant area of the land plot and the size of the roof of ground buildings. Allotments of more than 10–15 acres with building structures from 100–150 m² meet such requirements.

Storm sewer

The main purpose is the removal of liquid atmospheric precipitation, as well as moisture generated from human activities. For example, when washing a car, or from a backyard summer pool.

In the cold season, in the main part of the country, there is no need for "rainfall". Therefore, the depth of the storm sewer is determined by:

requirements of SNiP 2.04.03-85 “Sewerage. External networks and facilities”;
local climatic and geological conditions.

the average freezing depth is in the range of 0.7–1.2 meters; digging a deep trench in a relatively small area is simply impractical;
another limitation is the structure and composition of the soil; it is difficult to process rocky or viscous clay soil.

An important factor is economic. It is sometimes simply not profitable to build a drainage system that works episodically in the warm season in accordance with all the rules. But, precipitation must be removed. Practical options have been created:

Laying pipes in trays, with deepening into the ground and closing with decorative plates. In order to save land space, the structure is laid along the footpaths. Main advantages:

simplified installation;
saving time and material resources;
quick and easy access for maintenance or repair work.

Installation of storm collectors with a immersion of 30–50 cm. Heating is carried out by thermal electric cable. Additionally, if necessary, thermal insulation with mineral materials is arranged.

domestic sewerage

It is a system of interconnected:

manifolds, fittings;
inspection and overflow wells;
cesspool or septic tank;
more complex structure– station complete cleaning, includes drainage fields.

The drainage system is based on gravity or forced (pressure) pumping. In private housing construction, the first variant of wastewater disposal has been developed.

Collector material

Structures located outside the home are exposed to several factors:

inner surface the highway is in contact with solid and liquid wastes that form a chemically aggressive environment;
the outer side is in contact with the composition of the soil, groundwater, forming an alkaline and acidic environment;
the collector is affected by the weight from backfill soil;
in case of subsidence of the earth in some areas, bending loads begin to act on the pipe;
during the cold season, a temperature bridge is formed between the outer and inner walls with a range of 20–50°C.

The depth of the sewer in a private house affects the choice of products that are resistant to the listed effects. For outdoor use, PVC pipes (unplasticized polyvinyl chloride) are used. Most often, they have a red tint. The collector diameter is 110 mm, but it can be larger, 160 or 200 mm. The size depends on the daily volume of discharged effluents.

Laying rules

The development of laying rules is based on the requirements of SNiP 2.04.03-85 “Sewerage. External networks and structures”. Taken into account:

The local climatic factor is the level of soil freezing. The depth of laying sewer pipes depends on it. Optimum value: the lowest point with zero temperature plus 20–50 cm. Generalized data on this are given on the climatic map of the region. Information can be obtained from the local climate service.

Level ground water. This indicator determines how much it is necessary to deepen the product so that groundwater does not affect its performance.
Straightness of the gasket. The presence of bends, transitions, joints increases the risk of blockages.
Revision possibility. The extended highway needs periodic preventive inspections. To do this, it is necessary to arrange manholes every 25–40 meters.
The composition and structure of the soil. One of the main factors. In a private house, the depth of the trench is determined by the technical capabilities of its device. Sands, loams and clays are processed manually or by means of earthmoving equipment. Hence, it becomes possible to comply with all regulatory indicators. Rocks make adjustments to the laying scheme and installation method.
Pipe slope. Provides the necessary flow rate and removal of all residues from the collector.

The rules are taken into account when designing a drainage system. The project specifies the depth of the sewer, the laying scheme, the presence of intermediate wells, the dimensions of the trench and the collector.

Mounting

The depth of the sewer pipe is determined by the vertical dimensions of the trench. Mounting outdoor system drainage consists of the following stages:

preparatory work;
arrangement of trenches and pits;
pipe laying;
performance check.

Training

Before starting earthworks, the following is done:

cleaning the site from foreign objects, construction debris;
the future route is marked, the location of the manholes, storage tank (septic tank) is established;
the depth of laying the sewer pipe is checked against the existing relief;
fiducial points are marked at the junction of several collectors, the connection of stormwater structures and domestic discharges.

To the number preparatory activities applies to purchase required material and delivery of equipment.

The device of a trench, ditches

Sewer depth is the vertical dimension of the trench. The installation conditions depend on how the pit is correctly formed and dug. For comfortable work, the width of the earth gap is in the range of 50–70 cm. This value is affected by the vertical size, dimensions of the excavator and its technical capabilities.

Earthworks are carried out manually or with the involvement of earthmoving equipment. Depends:

on the dimensions of the trench (depth, width, length);
composition and structure of the soil;
the time of year when the work is carried out.

The bottom of the ditch is necessarily covered with a sand and gravel cushion with a thickness of

10–30 cm. The soil is compacted manually with a rammer or mechanically. By means of the layer, the level of the inclination of the highway is precisely set.

A pit for a sewage collector (cesspool) is easier to dig with a small excavator. But, if the soil is soft (sands, sandy loam, loam), then the operation is carried out manually. Under a septic tank or a treatment station, in effect overall dimensions structures, the pit is dug mechanically.

An important point is the shedding of the walls of the trench. This phenomenon is typical for deep (from 1.5 meters) ditches, equipped in light soil. Or the presence of underground quicksand (clay, sand, water) under a dense layer of earth. In such cases, it is necessary to observe safety precautions (for example, work together or in a team).

Note. In difficult conditions - rocky or viscous clay soil, the maximum possible vertical dimension of the trench is performed. But, in this case, measures for thermal insulation are necessarily carried out.

Laying

The sewer pipe is collected on the surface of the site. All necessary connections are made. The connecting nodes are treated with sanitary grease.

Note:

sockets are directed along the direction of flow, - the wide side is facing towards the movement of drains;
a pit is made under the location of the socket;
shaped elements, sockets cannot be shortened - this, in the end, will violate the strength of the connection and tightness.

It is necessary to lay the assembled highway with a single whip. Start of installation - from the building. Avoid sudden movements and strong bends. It is more convenient to work in two or three pairs of hands. The slope level is determined by the pre-tensioned cord. The exhibition is made by sprinkling or removing the sand and gravel mixture. From the displacement of the pipe, side pegs are driven into the sides.

It is allowed to assemble the system in a trench. In this case, the width must be at least 60 cm. In a narrower version, the soil from the side walls of the earthen device crumbles from the movement of a person.

In case of insufficient depth, - laying in the thickness of the freezing of the earth, the main line is insulated. Shell or matte thermal insulation is used. Another option is to use a thermal cable. The downside for the latter case is the availability of electricity (in winter, some country houses unplugged).

Protection against excess external weight (the collector is laid under the parking lot) is carried out by installing concrete trays or halves (the product is cut lengthwise) metal pipes larger diameter. It is possible to use corrugated (multilayer parts).

Examination

Burying a trench is allowed after commissioning. Stages:

the correct assembly of the line is checked;
the angle of inclination is measured, amendments are made;
the assembled structure is poured; identified deficiencies are eliminated;
the heat cable is tested (if any).

The collector is covered with a layer of sand and gravel mixture 20–30 cm thick. The sides of the pipe are sealed. Above the highway itself, such actions are prohibited, due to the possibility of damage to the assembled structure.

Advice. On the laying diagram, it is advisable to note the location of the line in fact. Make a binding on the ground (along the fence, house, outbuildings). This will make it easier to search for emergency situations especially in winter time.

hemkor.ru

We study the standards

All construction and installation work must be carried out in accordance with applicable regulations, rules and regulations. Such requirements are specified in GOSTs and SNiP. The same applies to the laying of storm sewers. There is SNiP 2.04.03-85, which is called “Sewerage. Outdoor structures and networks.

In some paragraphs of this document, the recommended depth of laying storm pipes is indicated. According to them, laying should be carried out:

for pipes with a cross section of up to 500 mm, at least 30 cm below the freezing level of the soil;
for pipes with a cross section of more than 500 mm - at least 50 cm.

But all these points regarding the depth of occurrence are rather advisory in nature. Their use lies on the conscience of installers and builders. According to SNiP, laying must be carried out based on the experience of operating sewer systems in each particular region. In general, the minimum depth should be at least 70 cm from the surface.

What depth to choose

The best option is to lay storm sewer pipes below the freezing level of the soil. When digging a trench, it is worth knowing this indicator, and even add to it the thickness of the sand cushion at the bottom. But in reality, this is not always possible.

In some regions of our country, especially those closer to the north, the freezing depth can reach one and a half or even two meters. Plus, the ground itself, it can be quite rocky.

In addition, it is necessary to take into account the requirements for the slope of the pipes. If it is not observed, then the water will not leave, then the efficiency of the stormwater will noticeably decrease. And in this case, and even if the terrain is uneven, the depth of some trenches can reach large values.

Some may ask a question - is it possible to lay pipes closer to the surface, because this is often done when installing domestic sewage? But in these systems there is a significant difference. It consists in the temperature of the drains.

Note! In domestic sewage, if people constantly live in the house, the temperature of the drains is always room temperature. Constantly flowing warm water and sewage heat up the pipes themselves and the space around them. As a result, freezing is unlikely.

There are no warm drains in the storm sewer. Yes, and there is not always water. All winter the pipes are empty, besides, the temperature is below zero. When spring begins, melt water enters the cold "dungeon". The result is icing and congestion.

If it is not possible to deepen the storm sewer below the freezing depth of the soil, then it must be insulated. Moreover, this issue should be taken very carefully. If the pipes have thermal insulation protection, then it is not worth deepening them into the ground.

How to insulate storm sewer pipes?

If a decision is made to lay storm sewer pipes above the freezing level of the soil, then they must be insulated. To do this, you can use various materials. But here the main thing to remember is that the insulation will constantly be in an aggressive environment.

Polyurethane can be used for pipe insulation. Today, special designs are produced from this material, which are easily put on pipes. Such a "shell" will reliably protect the stormwater from temperature extremes.

It is also convenient to use foam or polystyrene foam. Ready-made heat insulators are made from such material. It is made of two halves and easily snaps onto the pipe.

One of the modern heat insulators is penoizol. It is poured in liquid form directly into the ditch with the pipe. After hardening, it turns into a good and durable insulation. But for its installation it is necessary to use special equipment, which is not always possible.

But mineral wool and foamed polyethylene are not very suitable for insulating pipes in the ground. Even if you make a special box to protect the insulation, it is unlikely to last long enough.

Summarize

If we draw some results, we can draw the following conclusions:

The depth of laying storm sewer pipes should be greater than the depth of freezing of the soil, at least 30 centimeters.
If laying to such a depth is not possible, then the storm drain must be insulated. Otherwise, problems may arise in winter.

Determination of depth is an individual matter and depends on many factors. If the soil and terrain allow, then you can do everything according to SNiP. Well, if this is not possible, then it is worth insulating the pipes.

kanalizaciyavdome.ru

What are the general provisions of the storm sewer SNiP

SNiP for storm sewer number 2.04.01-85 provide for standards that must be observed at all stages of construction: from design to direct operation.

Today, such types of stormwater drainage as point and linear are actively used. The SNiP provides the most detailed requirements for the arrangement of a mainly linear type of sewerage. The whole complex of such a system consists of a network of disparate or interconnected channels located at a certain angle of inclination. They are designed to collect and divert rainwater and meltwater to appropriate collectors and reservoirs.

As a rule, linear sewerage is made according to closed type. Rainwater receivers are connected with pipes dug into the ground, they are connected to special collectors. Control and maintenance of the system is carried out using inspection manholes specially equipped for this purpose with a diameter of at least a meter.

Spot storm sewer, according to the document "Storm sewer SNiP", is designed for point collection of water and its removal from the building to the collectors. Water is collected by special storm water inlets. It is obligatory to have a protective cover on the storm water inlets, which prevents premature littering of the receiver's basket, and also provides unhindered passage for people and animals. The following elements of the storm sewer system are regulated by the standards:

storm water inlet. It is one of the main elements of the entire sewer system and serves to directly collect water;
pallet. It also serves to collect rainwater and is equipped at the entrance to the room;
chute or tray. These elements are mounted in drainage channels. Channels must be located at a certain angle to the collector in order to be able to provide a natural flow of water under the action of gravity;
pipeline. Designed in the same way as channels for natural water drainage, but through pipes that go deep into the ground;
sand trap. This device is designed to separate water from sand and other coarse debris;
observation (revision, inspection) well. Designed to inspect the network and to control the water level in it.

In addition, the document "Storm sewer SNiP" helps to determine the amount of expected runoff in accordance with the terrain, the nature of the soil, etc.

Calculation of the performance of a storm system

Despite the fact that SNiP for stormwater was approved 30 years ago, its relevance remains to this day. Based on its settings, you can easily determine what performance the system needs to be equipped in one place or another.

In general, despite the seeming cumbersome and confusing formulas and tables, for the owner of a private dwelling or suburban area it will not be difficult to make simplified calculations. As a result, it will be possible to obtain data on such system parameters as:

the degree of deepening of the pipes into the soil;
optimal angle of inclination of the pipe;
as well as the volume of water that must be diverted from the object.

Q is the total volume of water required for drainage;
q20 is the coefficient of average precipitation. It is measured in liters per hectare and is unique to a particular area. The corresponding values of this coefficient are taken directly from the SNiP documentation;
F - the area of the site on which the sewage system is equipped;
Ψ is the coefficient of absorption of moisture by one or another surface (it is also simply a correction factor).

For Ψ, the following coefficients will be relevant: indicator 1.0 - for an ordinary roof of a house, that is, there is practically no absorption; for asphalt - 0.95; for a surface like concrete pavement the correction factor will be already 0.85, and for crushed stone and gravel - 0.4. Finally, for open ground and lawn - 0.35.

By simply multiplying all the data, you can get the total volume of liquid for one storm water inlet under given conditions. As practice has shown, in the vast majority of cases, for private suburban land ownership, it will be enough to have pipes with a diameter of 10 to 11 cm, and in the case of a collector, this value will increase to 20 cm.

When designing, it is also necessary to take into account the possibility of manual cleaning of pipes or under high pressure, for example, using a household car wash. This is possible only when the diameter of the pipes does not exceed 20 centimeters. Otherwise, you can not do without the involvement of specialized equipment.

How to calculate the required angle of inclination

The standards in Storm Sewerage SNiP also allow the owner to calculate the optimal angle of inclination of the pipe. After all, as you know, wastewater is transported in a storm drain, obeying the force of gravity, that is, in a natural way and without the use of any pumps and other mechanisms.

However, it is not always easy to determine at what angle it is best to position the pipe to ensure smooth and uniform transport. Well, SNiP allows you to do this. Basically, it all depends on the diameter of the pipe. The calculation is made on the basis of a special table. But in most cases, the average owner can be guided by a simplified scheme:

for a pipe with a diameter of up to 110 millimeters, a slope of 2 centimeters for each running meter pipes;
for pipes with a diameter of 150 millimeters - from 8 to 10 centimeters;
for a sewer pipe with a diameter of 200 millimeters, a slope of 7 centimeters can be considered optimal;
finally, for pipes with a diameter of 500 millimeters, the slope should be 30 millimeters per meter of pipe.

Directly in front of the sand trap, the slope should be somewhat less so that even distribution of sand and liquid can be ensured. Otherwise, the streams run the risk of simply mixing with each other.

What does SNiP say about the depth of pipes

It may seem strange, but there is no specific indication in the documentation about this. Here, SNiP recommends rather than indicates. In general, it all comes down to combining such factors when determining the depth of laying a pipe as the degree of freezing of the soil, the location of the aquifer, as well as reliance on personal experience masters. However, you can still rely on the following general recommendations:

pipes with a diameter of less than 50 cm must be deepened to a depth of at least 30 cm from the place of soil freezing;
if the pipe has a diameter of 50 cm, then this depth should be increased to 50 cm.

However, in any case, the depth must be at least 70 centimeters, if you count from the soil surface to the uppermost edge of the pipe. In the same case, if for some objective reasons laying in the ground at a given depth is not possible, laying at a shallower depth is also allowed - but at the same time, it is necessary to take care of additional protection of the sewer pipe from external mechanical influences.

Well sizes and their distribution according to SNiP

But with regard to the location of the wells at the facility and their size, then in this regard, SNiP storm sewers can give quite definite advice. So, for example, regarding manholes, they must be equipped:

where the pipes join each other;
where the pipes have a sharp turn, change their direction;
in places where there is a difference in water pressure and a difference in its level;
where the pipe changes its diameter;
and even in ideally flat places of the pipeline, through equal distances. In this case, the following instructions are given: for pipes DN 150 - every 35 meters, DN 200 - 450 - every 50 meters, and for pipes DN 500 and more - every 75 meters. In a word, the thicker the pipe, the greater the distance through which inspection wells can be installed.

At the same time, the size of the big pipe that enters the well. For pipes larger than 600 millimeters in diameter, it is necessary to equip wells with a diameter of at least 1,000 millimeters. For an inlet pipe DN 150, a shaft with a diameter of 700 millimeters can also be dispensed with.

This also takes into account the depth of the well. In the event that this value is more than 3 meters, the diameter of the well shaft must be no less than 1,500 millimeters.

When laying an external sewage system, one of its most important parameters is the depth of the sewer pipes, SNiP stipulates both the maximum and minimum values \u200b\u200bof this indicator. Moreover, specific figures differ depending on the pipe laying methods and some other characteristics.

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These Sanitary Norms and Rules give a number of recommendations general, which must be taken into account when arranging sewer networks:

laying of external sewer networks is carried out on the basis of pre-compiled projects, which should take into account the development schemes of settlements and the location of other engineering networks in the ground;
when drawing up the project, one should take into account the possible further intensification of the use of the system (increased load on it);
it is desirable to develop a sewerage plan in conjunction with the design of other pipelines, in particular a water supply system.

The best option for building a network for draining sewage is considered to be such a project on which a reasonable minimum of funds is spent, while guaranteeing the stable operation of the sewer for the planned time.

At the same time, the depth of laying sewer pipes may (and should) differ from the SNiP standards, which is due to the characteristics of the soil in a particular area.

The conditions for arranging the network in Krasnodar, as you understand, will be different than in Vladivostok. This should always be taken into account when deciding to create a high-quality sewage system that will not freeze when cold weather sets in, or will not “creep out” in areas where soil shifts are noted.

The SNiP standards contain not only numbers, but also a “pleasant” phrase for designers of sewerage systems that “The depth of pipe laying is based on the operational experience of using networks in a particular region.” This means that a specialist has the opportunity to draw up a truly ideal project with reference to a specific area.

In general, the depth of laying a sewer pipe depends on four important factors:

on how the pipeline is laid (in trays or it is performed in the so-called "open form");
on the composition of the earth and geological conditions in the laying area;
on the degree of soil freezing in winter period(in cases where critical frosts are possible, the laying depth is increased from that recommended in the Sanitary Standards by 30 percent);
on the type of sewer system (it can be pressure or gravity).

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Some are sure that the reliability of the functioning of the sewer will be the higher, the deeper they dig. Such an approach, firstly, is not economically feasible (financial and labor costs), secondly, it complicates the system maintenance process, and thirdly, at great depths, the risk of fatigue cracks on the pipeline surface, caused by high pressure on the roof of the earth pipe, increases significantly.

Of course, no one needs the voiced problems. This means that it is required to act reasonably - to focus on the minimum depth of the pipeline elements, which is permissible according to SNiP. For pipes used to drain domestic wastewater (their cross section, as a rule, does not exceed 500 mm), it is allowed to lay the system to a depth of 300 mm from the ground. If pipe structures have a larger cross section (more than 500 mm), they must be placed at a depth of at least 500 mm.

Also, do not forget that domestic sewage, even in cold winter at the outlet are characterized by a fairly high temperature (about +18 ° C). Thanks to this, they do not freeze on the way to the collector. Therefore, it is possible to further reduce the depth of pipe laying in cases where the distance between the collector and the outlet of the system from the house is small.

Note that the minimum depth of laying sewer pipes (SNiP 2.04.03–85) also depends on the type of loads acting on the soil surface in the area of arranging the sewer system. If such loads are high (for example, there is regular traffic on the ground surface), the pipes should be buried 900 mm underground.

In situations where, for some natural or purely technological reasons, the recommended minimum depth for laying the sewer network cannot be observed, care must be taken to effective methods protection of pipes from freezing by applying modern methods of system insulation.

Possible options for reducing the depth of the (minimum) sewerage:

connection of special pumps designed to quickly clean pipes from drains in order to protect them from freezing (in this case, the sewer can no longer be called gravity, but semi-pressure);
use of structures with high rate strength (steel, for sewage), determined by the wall thickness of the product;
warming with the help of backfilling of the earth of individual sections of the system (underfilling is now understood as the arrangement on the surface of decorative flower beds, mounds-mounds that fit perfectly into the landscape).

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This indicator is also of great importance for the normal operation of the pipeline. The weight of the earth can significantly put pressure on the walls of tubular products in the ground. If the pipes are laid too deep, the probability of damage to the network increases. When carrying out repair work in this case, it will be necessary to carry out complex and voluminous earthworks.

SNiP recommends that for moisture-saturated soils and soils with rock inclusions, the maximum depth of laying the pipeline is not more than four meters. But for dry land, the laying depth is already taken higher - from five to eight meters.

If the specified standards for the project must be exceeded, it is imperative to use reinforced concrete trays in which sewer pipes are placed. Such trays can withstand heavy loads, therefore, they will reliably protect pipes from failure.

Professionals, in addition, are advised to purchase rigid pipes for situations where the sewer network is laid under the roadway or at great depths. The best option in this case are two-layer polyethylene corrugated pipes.

So, what depth of the sewer pipe can be considered ideal? Firstly, the one that complies with the Sannorms and Rules (or differs from the recommended indicators by insignificant values). Secondly, it must take into account the peculiarities of the climate and soil where the system is being laid. The main thing is that the network does not freeze during the cold season, since such a problem is really a huge nuisance. Take care of proper sewerage laying, and your life will be absolutely comfortable!

Designing a storm drain for a specific site, developing a layout for pipelines and wells. This stage of work is carried out taking into account the requirements set forth in the regulatory documentation - SNiP, SanPin, GOST, etc.
Approval of the project in the instances required by law
Construction of storm sewers in the selected area

A very important part of the project is the terms of reference of the system, which is compiled on the basis of GOST 19.201-78 and fulfills all the requirements for the designed circuit. This section contains not only a description of the purpose of the structure, but also the features of construction work, the timing of their implementation, a feasibility study, and so on.

The calculation of storm sewers provides for the determination of the following parameters:

Selecting the type of system - internal or external sewage
Determining the location of wells and their number
Calculating the length of pipelines
The choice of building materials necessary for the construction of the system

The main factors influencing the calculations are the climatic features of the region in which the site is located, the location of water bodies of any type nearby, the catchment area, the speed of precipitation, and more.

In order to predict material costs for the construction of a storm drain, it is necessary to draw up an estimate that contains the price of all components of the system:

Point catchment tanks
Downspouts
Storm wells
Waste water filters

Wells are a very important component of the system, since, depending on the type, they have a variety of purposes - the collection and accumulation of precipitation, their distribution before treatment facilities, diagnostics of the system, erosion of bottom sediment, as well as water sampling.

The storm sewer project includes the following sections:

System trace
Hydraulic network calculation
Linking and designing its elements

The estimated depth adopted in the design of the network, according to SNiP 2.04.03-85, is the depth used in the given region.

With a small amount of calculated data, the pipe laying depth is taken as follows: with a pipe diameter of up to 500 mm - 30 cm, with large diameters - more than 70 cm.

The optimal depth for laying storm sewer pipelines is one at which the amount of earthwork is minimal, as well as ensuring the integrity of the pipes, avoiding freezing of communications and the formation of ice in it.

The minimum slope of a storm drain system is determined by the type of surface coverage, piping diameter, and type of drainage system.

The calculation of storm sewers involves determining the slope according to the following principle: if the inner diameter of the pipe is 200 mm, the slope value should be 0.007 or more, and with a diameter of 150 mm - more than 0.008. Under certain conditions, the values can be reduced to 0.005 and 0.007, respectively, for given diameters.

For open gutters, the slope is:

Channel for drainage - 0.003
Tray of the road, the surface of which consists of asphalt concrete - 0.003
Tray of the road, laid with crushed stone or paving stones - 0.004
Tray covered with cobblestones - 0.005
A ditch with a separate location - 0.005

It can be concluded that the slope is directly proportional to the roughness of the material - the larger it is, the greater the value of the slope. With the diameter, the definition is different - with its increase, the slope number decreases.

With the independent construction of the drainage system, the principle of ensuring the necessary slope is adopted on the soil surface. For finished gutters, different principles apply.

The values that are presented in the regulatory documentation are empirically derived, that is, they were derived based on data obtained from a large number ready systems. Having correctly carried out the design and calculation of storm sewers, the system will turn out to be reliable, and its service life will be long.

You can’t just take and build a rain sewer: at least it will be inefficient, and at the maximum it will flood the site. We need a competent project, the pipeline must be laid correctly. We figure out what the depth of the storm sewer of a private house should be, how to make the right calculation according to SNiP, SP, GOST and common sense.

The current rules state that when developing a rain sewer project, it is necessary to take into account:

existing cleanup requirements;
climatic parameters of the area;
relief of the site;
geological/hydrological conditions;
situation with engineering communications;
other factors (as it is written).

Climatic parameters are contained in SP 131.13330. The rest is individual.

Components of the system

The system consists of storm water inlets, pipelines, collectors, manholes. The design of storm water inlets depends on the type of system - linear, point, combined. Trays are used in linear ones, ladders are used in point ones. Elements protect from littering - protective grids are included.

Put on pipes check valves so that in the event of an overflow or blockage, water does not fill the pipeline. The pipeline is laid at a certain slope and at a certain depth.

Depth of storm sewer

This parameter depends on the geological conditions in a particular region and the experience of operating engineering networks. It is regulated by SP32.13330.2012 (in an updated version). Specifically for a private house, the numbers are not spelled out - the rules relate to systems arranged in a residential area.

In case of lack of experience (non-canalized area, for example) in the operation of networks, they rely on the level of soil freezing, which is different in all regions.

Pipes with a diameter of less than 500 mm are laid 30 cm below the freezing depth mark.
Pipes with a diameter of more than 500 mm are laid 50 cm below the freezing depth mark.
It is permissible to lay pipes to a depth of 70 cm from the surface (layout). This is the distance to the top of the pipe. At the same time, thermal insulation of the pipeline and its protection from mechanical influences are provided.
The depth of the collector is determined by statistical and thermotechnical calculation.
The maximum depth is not standardized - it is determined by calculations for each individual case. The materials used, the characteristics of the soil, the technologies used are taken into account.

Reality is very far from book truths. Sometimes it is impossible to follow the rules for a number of reasons. Deviations are allowed, but any custom solution, which is not prescribed in the rules and regulations, needs the approval of the relevant authority, that is, the project must be agreed upon.

In order for the project to be approved, all applied technical solutions must be justified, and in a comparative way. That is, you need to compare the technical and economic parameters of different options and prove that either the best or the only possible one is designed.

Calculation of storm sewers

There is a whole array of numbers and formulas in the calculation of storm sewers, but if we simplify everything utterly, several parameters are important:

system performance (volume of drains);
pipe slope;
pipe diameter;
depth of the pipeline and collectors.

The efficiency of surface runoff removal depends on the diameter of the pipes. The diameter, in turn, depends on the amount of precipitation in the area and the area of the service area (including the drainage system, if one collector is used). All the necessary numbers are in the regulatory documentation, and they are enough if you follow the rules.

Combined system (stormwater and drainage)

The volume of effluents is calculated by the formula:

Q - stock volume.
q20, l/sec., per ha - precipitation intensity factor.
F - the area of the served territory (recalculated in hectares; roof slopes - in a horizontal projection).
Ψ - coefficient of absorbency of coatings.

The q20 value is obtained from the local meteorological center. Ψ standard:

1.0 - roof;
0.95 - asphalt;
0.85 - concrete;
0.40 - crushed stone (rammed);
0.35 - soil (including turf, lawns).

For each storm water inlet, a separate calculation is made. Then the obtained figures are summed up and the diameter of the pipes is determined.

Normative documents

The set of rules regulates the smallest diameter of pipes. For gravity networks, it is 150 mm (and it goes as acceptable, and desirable - 200 mm). Using other pipes, violate the provisions of the joint venture. In production networks, the use of 150 mm pipes requires justification.

Parameters valid for pipes 150 mm:

calculated maximum speed: for metal pipes - 10 m / m, for non-metallic - 7 m / s;
calculated filling of rectangular channels and pipes of cross section - full;
the smallest slope (the need for a smaller slope should be justified): for 150 mm pipes - 8 mm / meter, for 200 mm pipes - 7 mm / m;
connection slope - 2 mm/m;
slope of individual trays - 5 mm/m;
the smallest dimensions of trapezoidal cuvettes, ditches: along the bottom - 30 cm, along the depth - 40 cm;
between the outlet and attached pipes, an angle of at least 90 degrees is required, otherwise a well is installed, and in it - a riser with the connection of storm water inlets with a drop;
require a well device: long straight sections (every 35 m - for private households), turns, drops, turns on collectors, connected pipes of different diameters;
the radius of the turning curve of the trays must be at least 1 pipe diameter;
the radius of the turning curve on the manifold from 120 cm (inclusive) must be at least 5 pipe diameters, manholes are needed both at the beginning and at the end of the curve;
collector diameter for pipes up to 500 mm - 1000 mm (1000x1000);
installation of a collector with a diameter of 700 mm for pipes of 150 mm is permissible;
the depth of the collector with a diameter of 700 mm should not exceed 1200 mm;
the diameter of deep wells (from 3 m) should be at least 1500 mm;
the minimum design speed of effluents through pipes and channels is 60 cm/s.

You can not rely on the figures given, using pipes of smaller diameter: already 110 mm is needed minimum slope at 2 cm/m. In each case of violation of the rules, you will have to make an individual calculation of storm sewers.

Programs for calculating storm sewers

There is advice to use AutodeskBuildingSystems, but it's like hammering nails with a microscope. Theoretically, it is possible to calculate storm water in any program that, in principle, can design engineering networks, but in practice we do not recommend it. Firstly, this kind of software is never free (except perhaps the trial version, but it is always cut off). Secondly, it is difficult for an ignorant person to understand professional software. Thirdly, such software is not needed for our small task.

You can calculate rainwater drainage on specialized resources that provide calculators or programs that work in a browser (we launch and count). Most (maybe all) of them do separate calculations:

hydraulic,
surface runoff from the territory,
volume of water from the roof,
collector capacity,
pipeline slope,
network depth.

If these parameters help to build a stormwater… good luck.

We have written down the rules and regulations, formulas and figures, based on SNiP and SP, but according to common sense, the calculation of rain sewers should be entrusted to specialists - no matter how trite it may sound. Yes, all the figures are given, but the main factor was, is, will be the climatic parameters, although they are indicated in the joint venture, but not completely. The joint venture does not know what kind of soil is on your site: sand passes water instantly, clay does not pass at all. Calculation error = flooded area with all the consequences.