Calculation of storm sewers: analysis of important design features

Characteristics and types

Flexible hose for plumbing is a hose of different lengths, made of non-toxic synthetic rubber. Due to the elasticity and softness of the material, it easily takes the desired position and allows installation in hard-to-reach places. To protect the flexible hose, the upper reinforcing layer is designed in the form of a braid, which is made of the following materials:

• aluminum. Such models withstand no more than +80 ° C and retain functionality for 3 years.In high humidity, aluminum braid is prone to rust.
• Of stainless steel. Thanks to this reinforcing layer, the service life of the flexible water supply is at least 10 years, and the maximum temperature of the transported medium is +95 °C.
• Nylon. Such a braid is used for the manufacture of reinforced models that can withstand temperatures up to +110 ° C and are designed for intensive use for 15 years.

Nut-nut and nut-nipple pairs are used as fasteners, which are made of brass or stainless steel. Devices with different indicators of permissible temperature differ in the color of the braid. The blue ones are used for cold water connections, and the red ones for hot water.

When choosing a water supply, you need to pay attention to its elasticity, reliability of fasteners and purpose. It is also mandatory to have a certificate that excludes the release of toxic components by rubber during operation.

Materials for arranging storm sewers

The project documentation should describe the requirements for the components and materials used for the installation of storm sewers. Their selection is carried out as follows.

Pipes. They can be rigid, made of PVC. Another option is corrugated pipes. PVC pipes are usually laid at shallow depths. Corrugated polymer pipes are more durable, and therefore they are used in the construction of sewers with significant depth. It is also possible to lay asbestos-cement or metal pipes.Their specialists from the Mos-drainage company recommend installing under sections of the roadway, parking lots - where an increased mechanical load can act on the pipeline.

Storm water inlets. They can be made of polymeric materials or polymer concrete. They are additionally equipped with siphons, in which small rubbish, dirt, silt settle. Polymer concrete products are used if it is necessary for the receiving device to have increased strength. Plastic storm water inlets are more affordable, they are easier to install, and have a smooth surface. At the same time, plastic is not as strong as fiber-reinforced concrete, and therefore products made of it, as a rule, are installed in private facilities with a small load.

Door trays. Are wide, from above are closed by a lattice. Used to drain the area directly at the entrance to the house. The door tray has an outlet that connects to the storm sewer pipe. The outlet and the pipe must match in diameter.

Wells. They are made of plastic or reinforced concrete. The first option is used much more often due to its affordable price, low weight, and simple installation. The well must be selected not only in size, but also in terms of resistance to ascent, strength characteristics, and installation parameters.

In "Mos-drainage" you can order the design of storm sewers, its arrangement and the supply of all necessary materials and components. We guarantee efficiency and high quality of work.

What is drainage

In fact, this is a system by which water is removed from the surface of the soil or from a certain depth. This is one of the drainage systems. It achieves the following:

Water and moisture are removed from the areas where the foundation structures are located. The thing is that excessive moisture, especially for clay soils, causes foundation movements. As the builders say, it will "float", that is, it will become unstable. If we add frosty heaving of the soil to this, then the earth will simply push the structure out.

Lack of drainage on the site - wet basements in houses

• Basements and basements are being drained. Many may note that modern waterproofing materials are able to withstand any exposure to water, in any quantity. Nobody is going to argue with this. It's just that each material has its own operational resource. In a few years, even the highest quality waterproofing material will dry up. That's when the problems begin. In addition, there is always a possibility that there is a defect in some section of the insulation through which moisture will penetrate into the basement.
• If an autonomous sewage system with a septic tank is used on a suburban area, then the drainage will help the latter to stay in the ground. Taking into account, if the dacha has an increased level of groundwater.
• It is clear that the drainage system does not allow waterlogging of the soil. So, we can say that plants planted in the ground will grow normally.
• If the summer cottage is a territory located on a slope, then during precipitation, rainwater will wash out the fertile layer. This can be avoided by arranging drainage in a sloped area into which water flows are redirected. That is, they will be removed according to an organized system, without affecting the soil.

On the slopes, fertile soil is washed away by rain

We must pay tribute to the fact that not all suburban areas require the creation of a drainage system. For example, if it is located on a hill. Basically, there is always a need for it. Let's look at situations in which drainage is indispensable.

When should drainage be provided?

That is, we will indicate those cases when the drainage system is necessary in any case.

• If the suburban area is located in the lowlands. All atmospheric precipitation will flow down the slope here. The laws of physics have not been repealed.
• If the site is located on a flat area, the soil is clayey, the groundwater level is high (not lower than 1 m).
• Drainage on a site with a slope (strong) is also necessary.
• If you plan to build buildings with a deep foundation.
• If, according to the project, the main part of the territory of the summer cottage will be covered with a waterproof layer: concrete or asphalt paths and platforms.
• If lawns, flower beds are equipped with an automatic irrigation system.

If automatic watering of lawns is organized at the dacha, then drainage must be built

Where to start the construction of drainage

It is necessary to start with studies of a suburban area for the type of soil, the level of groundwater and the type of relief. This can only be done by professionals by conducting geological and geodetic surveys. Usually they make a topographic survey of the site, where the cadastral boundaries of the cottage are determined. The terrain is determined (wavy or even, with a slope in which direction), the type of soil, making exploration by drilling, and the physical and chemical properties of the soil. Be sure to indicate the UGV in the reports.

Based on the data provided, recommendations are formed on the depth of foundations, the type of waterproofing and drainage system.Sometimes it happens that experts generally do not recommend building large houses with basements, as the owners of the suburban area intended. Which leads the latter into bewilderment. Disappointments appear, but there is no way out.

It is clear that all ongoing research costs money, sometimes a lot. But you should not avoid these expenses, because the information received will subsequently save much larger capital investments. Therefore, all these studies, only at first glance, are unnecessary procedures. In fact, they are useful and necessary.

Checking the level of groundwater occurrence by drilling

Features of designing a storm sewer for a warehouse

When choosing drainage systems, it is necessary to take into account, in addition to the factors listed in the article, several important ones:

• In addition to the hydraulic load, the dynamic load is also taken into account, that is, depending on the flow velocity, the tolerances for the materials used are determined.
• To protect the system from debris and dirt, it is required at the design stage to provide water inlets, sand traps, inspection hatches, and garbage bins. Also, to prevent the release of foreign odors from the system, it is required to build in a siphon.
• The design of the tracks should not contain turns, the angle of which exceeds 90 degrees.
• It is necessary to take into account the filling of pipes. For example, the WAVIN QUICK STREAM system, due to the use of Bernoulli's law, is filled to 100%, unlike traditional systems, where the filling of pipes is no more than 50% due to the air column inside. The siphon-vacuum principle of operation removes intense precipitation much more efficiently.
• Depending on the material of piping storm systems, operating costs vary greatly. According to the joint venture, metal pipes must be regularly covered with an insulating layer; they rust and wear out. The situation is similar with other materials (cast iron, asbestos-cement, reinforced concrete pipes). It is more efficient and cost-effective to use plastic pipelines (HDPE). In comparison, WAVIN QUICK STREAM does not need to be painted, the system is not subject to corrosion, and does not require additional maintenance costs.
• When designing, loads on load-bearing structures are also taken into account.

If you have any difficulties when designing a storm sewer for a warehouse, or you need qualified advice on the use of the WAVIN QUICK STREAM siphon-vacuum storm sewer system, you can contact the designers from the manufacturer. The strategy of an individual approach provides:

• Free design of knots and fastening systems.
• Development of axonometric diagrams using special software (fully compatible with Autodesk Autocad and REVIT).
• Departure of a specialist to the object for preliminary coordination of the calculation, consultation, assessment of the quality of installation.
• Individual production of fasteners, taking into account the features of your project.
• Full technical support.

Elements of the drainage structure

What is a drainage system? This is a network consisting of various components, the main purpose of which is the removal and collection of capillary water contained in the pores of non-cohesive soils and cracks in cohesive rocks.

The main underground elements are drainage pipes.They should not be confused with water supply and sewerage systems, since only waters that are in the upper soil layers move through them. And the collection and drainage of rain and melt water is handled by storm sewers.

More elastic corrugated models are popular. The diameter of the pipes depends on the volume of the discharged liquid, the standard cross-sectional dimensions are: 50 mm, 63 mm, 90 mm, 110 mm, 125 mm, 160 mm, 200 mm. For central highways, products of a larger diameter are selected, for branches - a smaller one. Reinforced pipes consist of 2 layers.

The modern type of drainage pipes are products made of durable and heavy-duty modified plastic (for example, HDPE). The walls of the pipes are covered with filter holes or cuts, some top views are covered with geotextile

At the junctions of several hoses or in areas where the pipes turn at a large angle, technical (revision) wells are installed from a similar material. These are wide sections of corrugated pipes or specially manufactured factory models.

The drainage system may also include storage wells, which are installed at the lowest points of the site for efficiency. Accumulators suit if it is not possible to dump the discharged water into a nearby reservoir. All drainage lines lead to wells. They transport water, which is often used for irrigation or household needs.

If the terrain does not allow a gravity system, drainage pumps are used. Various models (usually submersible type) are used to pump water through pipes in the right direction, differ in design features and power

In addition to the main elements of the system, fittings for connecting pipes, geotextiles and building material for arranging trenches and wells (sand, gravel or crushed stone, concrete rings, bricks) will be required.

SNIP

The construction of schemes requires compliance with all the rules prescribed in SNiP 2.04.03-85, this document takes into account the needs of the owners and regulates the rules that must be taken into account when conducting sewer networks. This document is a necessary and useful instruction that cannot be neglected when upgrading an old site or building a new one.

SNiP for storm sewers contains all the necessary calculations for the performance of work, system design. It also contains recommendations on the basic rules of operation. Today, the most popular types of stormwater are:

• Point sewerage system
• Linear system

Required information for a development application

An application for the design of storm sewers is submitted to the design organization selected to prepare all the necessary documentation. Information must be attached to the application, namely:

• topographic plan of the land plot;
• data of geological surveys of the state of soils on this land plot;
• town-planning plan of the territory;
• technical conditions for connection to external engineering communications;
• the preferred method of removing rainwater from the site, etc.

The formation of the terms of reference is carried out taking into account the wishes of the developer and the information provided by him to the design organization. In turn, the drainage and storm sewer project is created according to the terms of reference.

The design and estimate documentation contains a diagram of the laying of pipes and locations of storm water wells, as well as other elements of the storm sewer system

From several trial versions of the project, one main one is selected, which, according to the customer and designers, is the most effective. After agreeing on the selected version, all particular details of the engineering structure are worked out.

As a result, the customer receives design and estimate documentation, drawn up in accordance with accepted standards. An explanatory note with the following sections is attached to the graphic part of the project, consisting of various drawings:

• general data of the project (list of working drawings, characteristics of the equipment used, etc.);
• storm sewer scheme;
• plans of the territory, which indicate the exact location of all elements of storm sewers;
• Hardware Specification;
• calculation and justification of the financial part of the project.

Only trained specialists can deal with the design of storm sewers. If you do not know how to calculate the sewerage for the removal of rainwater from the site, then contact the professionals. Make sure that the design organization is licensed to provide such services.

The purpose of the drainage of the garden plot

Land reclamation measures, in accordance with the norms (SNiP 2.06.15), are carried out in forest and agricultural lands so that the soil becomes as suitable as possible for growing fruit trees, cereals and vegetables.

For this, an extensive system of open ditches or closed pipelines is formed, the main purpose of which is to drain overly wet areas.

The ultimate goal of collecting water through branches and sleeves of various types is artificial or natural reservoirs (if conditions permit), special drainage ditches, absorbing wells or storage tanks, from which water is pumped out for irrigation and maintenance of the territory.

Often, pipes buried in the ground, if the relief allows, are replaced by external structures - ditches and trenches. These are open-type drainage elements, through which water moves by gravity.

According to the same principle, a pipeline network is designed for a summer cottage, regardless of its area - 6 or 26 acres. If the area suffers from frequent flooding after rain or spring floods, the construction of catchment facilities is mandatory.

Accumulation of excess moisture is facilitated by clay soils: sandy loam and loam, because they do not pass or very weakly pass water into the underlying layers.

Another factor that encourages thinking about a drainage project is the elevated level of groundwater, the presence of which can be found out even without special geological surveys.

If on the territory of the dacha a pit was dug for a cesspool or a septic tank, and it was filled with water, then the aquifers are located in close proximity to the surface of the earth. When arranging a well by a drilling organization, you will receive data on the location of water horizons from specialists.

Even if the foundation stands, there is no guarantee of maintaining a comfortable environment inside basements and basements: dampness, premature corrosion, fungus and mold may appear.

Over time, damp concrete and brick foundations become covered with cracks that are difficult to repair. On the contrary, they continue to grow, provoking movements of buildings. To prevent destruction, even at the stage of building construction, it is necessary to think about the device of effective drainage.

Excess moisture in the soil is always a danger to the integrity of the foundation of building objects: houses, baths, garages, outbuildings

Types of storm sewers

Before you begin to perform calculations, you should decide on the type of storm sewer. Advice! Despite the fact that the deep drainage system and storm sewers are often built in parallel, according to the requirements of SNiP, they should not be combined. They are placed in parallel, one above the other, while the storm system should be above the drainage system.

Types of storm drains according to the method of water drainage

There are three types of drainage systems for rainfall water:

Closed drains. This is the most difficult option, for its implementation you need to perform a serious hydraulic calculation in order to choose the right pipe diameter. Water in this case is collected in special collections - storm water inlets, trays. Then the collected moisture enters the pipe system, through which they move by gravity or with the help of pumping stations. Water enters the collectors, from where it is discharged outside the site, an example of a possible outlet direction is reservoirs, ravines or drainage installations.

• Open drains. This option, on the contrary, is the simplest. In this case, the moisture is collected and removed by means of a system of trays installed in ditches dug with an inclination towards the collector. Trays from above are covered with decorative removable lattices.
• Mixed sewers.This option for arranging the system provides for the installation of elements of both types mentioned above. Mixed conduits are built to reduce the cost of building closed systems.

If it is planned to build a closed or mixed type system, then pipes with a diameter of 100 to 150 mm are used for private buildings. You can more accurately determine the diameter of the pipes by calculating, taking into account correction factors. When performing calculations, not only the diameter is taken into account, but also the level of slope of the pipes to ensure the optimal flow rate.

Types of storm drains by type of drainage system

• Spot water collection. It is carried out by installing local storm water inlets connected by pipes into a single network. It is necessary to plan the installation of fence points in problem areas, for example, under drainpipes and in lowlands on the territory of home ownership.
• Linear collection of water. This option is suitable for collecting moisture from large areas, an example of such areas is paved areas, concrete paths, etc.

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System design and installation of storm sewers in a private house

Before creating any drainage system, it is necessary to draw up a drawing in advance, prepare plans for the territory and make detailed design diagrams. Otherwise, you will greatly complicate the work, for sure, in one of the sections you will make a mistake with the slope. If you can’t make an efficient system, then it’s better not to start this business, otherwise you will waste your money, and if you make a stormwater system that is too powerful, you will waste a lot of money.

To accurately perform calculations and prepare a project, you will need the following data:

• Average amount of precipitation;
• Precipitation frequency;
• Thickness of snow in winter;
• roof area;
• Runoff area;
• Soil characteristics on the site;
• Drawing of the location of underground utilities;
• Calculation of the possible amount of wastewater.

After that, calculations are made according to the formula Q \u003d q20 * F * K, in which:

• Q - the amount of water that must be removed by storm sewers;
• q20 is the amount of precipitation (we need data for a certain area);
• F is the area from which precipitation is removed;
• K - coefficient, which is affected by the coating material:
  • Crushed stone - 0.4;
  • Concrete - 0 0.85;
  • Asphalt - 0.95;
  • Roofs of buildings - 1.0.

These data are compared with the requirements of SNiP and decide what pipe diameter is required for high-quality drainage.

Often the high cost of earthworks causes people to lay pipes shallowly - this is justified, there is no particular need to bury pipes too deep. Inspection wells and collectors must be buried below the freezing depth of the soil, as indicated in GOSTs. You can lay them higher, but you will need to insulate the pipes with heat-insulating material, for example, you can use geotextiles. Reducing the depth significantly reduces the cost of a storm sewer device.

It is impossible to neglect requests for the minimum slope of the pipeline; according to GOST, the following standards are provided:

1. Pipes with a diameter of 15 cm must be laid with a slope of at least 0.008 mm per linear meter;
2. Pipes with a diameter of 20 cm must be laid with a slope of at least 0.007 mm per linear meter.

The slope may vary, taking into account the characteristics of the territory on the site near the house.For example, at the junction of a storm water inlet and a pipe, it is necessary to increase the speed of the water, for this it is necessary to increase the slope by 0.02 mm per linear meter. In the area where the sand trap is located, it is necessary to reduce the flow rate, otherwise the suspended sand particles will not linger, and they will be carried away by the water flow, for this reason, the pipe slope angle is reduced.

Estimates for storm sewers: ways to optimize costs

A typical storm sewer consists of the following elements - water collectors, drainage pipes, sand collectors, intermediate wells (inspection and drainage) and a wastewater collection tank.

Scheme of installation of storm sewers

1. Moreover, the best results are shown only by a fully equipped sewer, in the design of which there are all of the above elements. Therefore, saving estimates by excluding any components is far from the best solution.

However, no one prevents us from combining some elements "in one bottle". For example, a manhole with a difference in nozzles can be turned into the same sand collector. And instead of trays - quite expensive products - use a perforated drainage pipe laid in a ditch filled with rubble.

2. In a word, there are a lot of options for combining functions. And each promises all tangible savings. In addition, it is possible to reduce the estimate by optimizing the size of sewage conduits or drainage wells. After all, the dimensions recommended in SNiP (200-250 millimeters) are suitable for industrial buildings and for entire blocks of one-story buildings.

3.But for a separate house equipped with a non-pumpable storm well, a 100 mm pipe is enough (a 150 mm pipe can be used to protect against flooding). The result is one and a half, and even double savings only on pipes.

4. Another way to save is the already mentioned non-pumping storm well, buried to the horizon with high permeability. From such a well it is not necessary to pump out water or connect it to the central sewer. The drains will go away on their own, dissolving in sand that conducts moisture well.

As you can see, a creative approach to design gives a real chance for savings.

Really large buildings with a large roof or industrial facilities are best equipped with storm sewers, equipped according to the recommendations from GOST and SNiP. Otherwise, the owner of such facilities may pay a double price for their own indiscretion (and this is without taking into account the cost of dismantling an unsuitable stormwater drain).

Published: 05.09.2014

How much does school storm sewer cost?

The total cost of commissioning a storm sewer consists of the development of project documentation, the purchase of pipes, earthworks, subsequent maintenance and cleaning. The estimate for the finished storm sewer of the school also directly depends on the following factors:

• Forms and areas of the roof.
• Technical conditions at the facility.
• Building plans.
• The piping system used.
• Requirements and wishes of the customer.
• Additional works (dismantling, delivery, lifting of materials, preparation of the facility for installation).

It is necessary to determine the type of pipelines individually.For example, the WQS system may seem more expensive at first glance. However, given the advantages of a siphon-vacuum system (fewer risers, fewer funnels, smaller pipe diameters, no slope required, savings on earthworks), WAVIN QUICK STREAM can be much more profitable than gravity systems. This is especially true when working with buildings of a large area.

Features of the design of storm sewers of the plant

When designing a storm sewer for an industrial building, the following factors should also be considered:

• Dynamic load - it is associated with hydraulic and occurs during the movement of the flow. The higher the speed of movement of wastewater (for example, during heavy rain), the higher the dynamic load.
• Difficulty in predicting precipitation makes it necessary to provide a performance margin. If you improve the efficiency of drainage, the risk of flooding, destruction of communications, and damage to roof structures is reduced.
• In addition to the costs of design, installation and procurement of materials, there is another category of budget - operating costs. For example, cast iron and steel pipes require regular SP treatment to prevent corrosion.

Siphon-vacuum storm sewer QuickStream eliminates most of the problems associated with the design, installation, operation of the drainage system:

• Qualified support for designers, up to free hydraulic calculations of the siphon-vacuum operating mode system - axonometric diagrams are designed in special software certified in the Russian Federation, fully compatible with Autodesk Autocad and REVIT.
• There is no need for a horizontal slope - due to the siphon-vacuum effect, earthworks are reduced, installation is simplified, pipes can be mounted without complex fastening structures and constant control of the slope angle for efficient draining.
• The internal space is effectively used - by reducing the risers, reducing the diameter of the pipes, a small distance between the main pipelines and the roof.
• The pipes create a high flow rate (up to 40 l / s) - this leads to more efficient removal of water, especially during prolonged downpours or sudden changes in the weather.
• Self-cleaning WAVIN QUICK STREAM simplifies regular maintenance of pipes, flushing them is not required even after many years of operation. In addition, the absence of corrosion and the properties of HDPE allow fewer inspection hatches to be installed.

Features of installation of storm sewers of the plant

In moderate rainfall, if a QuickStream siphon/vacuum system is used, the effluent flows by gravity. As the intensity of rain or snowmelt increases, the pipes are completely filled with liquid and the system switches to a pressure mode of operation. This principle allows you to get a number of advantages in installation:

• Saves space near the ceiling;
• The entire volume of premises is effectively used, which makes it possible to rationally place production equipment, lay communications;
• In the event of heavy rainfall, funnels of a special design cut off the air and the system goes into pressure mode, transporting 2-3 times more wastewater than gravity storm sewers.

Stormwater types

Sewerage, designed to drain melt and rainwater, is of two types:

Point provides collection of water from the roofs of buildings. Its main elements are rain inlets located directly under the downpipes. All catchment points are provided with special sedimentation tanks for sand (sand traps) and are interconnected by a single highway. Such a sewerage system is a relatively inexpensive engineering structure that can cope with the removal of yards from roofs and yards.

Linear - a more complex type of sewer designed to collect water from the entire site. The system includes a network of ground and underground drains located along the perimeter of the site, along the footpaths and the yard. Usually, water from drainage systems placed along the foundation or protecting the garden and garden beds is diverted into the common collector of a linear storm. The system is extremely sensitive to slope towards the collectors. If it is not observed, the water will stagnate in the pipes and the drainage system will not be able to perform its functions.

According to the method of water drainage, stormwater is divided into:

On open systems that collect water through trays and deliver it to collectors. The trays are covered with shaped gratings on top, which perfectly complement the landscape design and provide protection from debris. Such systems are mounted in small private areas.

Such a project is implemented in practice by constructing canals that connect the catchment trays to each other and, ultimately, divert the collected water outside the designated area.

For mixed-type drainage systems - hybrid systems that include elements of closed and open systems. They are built most often to save the family budget. Outdoor elements are easier to install and cost less.

For closed systems consisting of storm water inlets, flumes, a pipeline and a collector that opens into a ravine or reservoir. This is an ideal solution for draining streets, industrial sites and suburban areas with a large area.

On the sewerage of open type in industrial execution. The main structural elements are concrete trays, on top of which lattice metal sheets are superimposed. By the same principle, open stormwater schemes for private housing construction are built.

The collected water is discharged through networks of pipelines laid and hidden underground. As a rule, the collected precipitation products are discharged to treatment facilities and further into the water area of ​​natural reservoirs.

Separately, it is necessary to highlight the ditch (tray) system for collecting and discharging rainwater. This storm sewer scheme, along with a simple scheme for its manufacture, is inherent in the versatility of operation.

Ditch storm sewerage has the advantage that, together with the function of removing rainwater, it can play the role of a supplier of moisture for agricultural plantations. It is also an economical construction option compared to other projects.

Thanks to the ditch design, it is possible to organize not only quite effective drainage of atmospheric precipitation products. The same system can be successfully used as an irrigation structure, for example, for the needs of a household (dacha) economy.

Conclusions and useful video on the topic

Arrangement guide surface drainage systems can be viewed in the following video:

A properly designed and installed drainage system will help maintain an attractive appearance for landscaped areas of a modern city, garden plots and private households. It will also extend the life of roads, bridges, foundations of buildings and residential buildings, reducing the hydraulic load on structures. But to create a drainage project, it is better to contact specialists who will take into account the type of soil, climatic features and a number of other important points.

Do you have your own opinion on the feasibility of installing a drainage system? Or do you want to supplement the above material with useful recommendations and facts? Write your comments, participate in discussions - the comment form is located a little lower.