To select the type of groundwater flood protection system to be built on a site, there is a drainage classification that gives the developer a complete picture of one or another of its types.

This article will discuss drainages of various types and their features of their design.

Types of drainage systems

The most commonly used types of drainage systems include:

• Ring drainage.
• Wall drainage.
• Reservoir drainage.

Let's talk about each of them in more detail.

Ring drainage

Ring drainage is used to protect the basements of buildings laid on sandy soil. In this case, it is possible to install deep drainage for a group of adjacent buildings. When protecting particularly deep basements, when the general drainage system of the area does not sufficiently lower the groundwater level, this type of drainage is also used.

It is permissible to organize an open drainage ring in the case when groundwater approaches the building from one side.

Pro tip: It is recommended to lay the ring drainage at a distance of 5 to 8 m from the walls. If the location is closer, it will be necessary to take additional measures to prevent soil settlement under the foundation of the house.

Wall drainage

Clay and loamy soils at the construction site require the use of a wall drainage system. Its features are as follows:

• Surface drainage is installed along the perimeter of the building at a distance from the wall determined by the width of the foundation and the location of the inspection wells.
• If a house under construction is located on combined sites (with different types of soil), ring and wall drainage are used simultaneously.

Pro tip: The use of modern polymer materials as a filter material will reduce the amount of sand and thereby reduce the costs of constructing a drainage system.

Reservoir drainage

In particularly difficult hydrogeological conditions, it is necessary to install reservoir drainage. This type of drainage is used:

• in the presence of a large powerful aquifer;
• when the groundwater level is insufficiently reduced by other types of drainage;
• with a layered structure of the aquifer;
• in the presence of underground pressure waters;
• if there is a lens directly under the building.

Basements and structures that require absolute dryness and absolutely do not allow the appearance of moisture during their operation are also a reason to use reservoir drainage. For such specific structures, it is practiced to install “preventive” reservoir drainage even in clayey soils and loam.

Local drainage

There are also different types of local drainage for various types of small building and other elements:

1. Drainage of collectors and underground channels. Underground collectors and heating network channels laid in aquiferous soil require protection from groundwater. Accompanying soil drainage in clayey soils is arranged along the axis of the channel at a depth of 0.3 to 0.7 m under the base of its base. In this case, inspection wells are embedded in the bottom of the canal. The reservoir drainage is connected to the filter layer of the tubular drainage.
2. Pit drainage. Depending on the specific conditions of the area, certain methods of drainage of pits are selected:

• possible deepening of the lower section of the drainage system if the pits are located close to it;
• a general decrease in the laying level of the drainage system during construction on sandy soil;
• additional local drainages;
• dividing drainage into parts.

In this case, special attention should be paid to measures that prevent the removal of soil from under the house foundation.

1. Drainage of filled-in ravines, streams, rivers. When backfilling small rivers and streams that provide natural drainage of water, a device should be provided for receiving and draining not only surface water, but also groundwater. A large flow of underground water requires the installation of two drains in clayey soil parallel to the walls of the collector. In sandy soil, it is possible to install one drain on the side with a large influx of water.
2. The drainage is wall and slope. Wall drainage involves the installation of continuous backfill along retaining walls in places where groundwater emerges. With a short length it can be carried out without the use of pipes. If the aquifer is not clearly defined, a special slope drainage is arranged.
3. Drainage of basements of existing buildings. To protect the basements of already constructed buildings from flooding, drainage is selected that is suitable for each specific case. Sandy soil requires the use of ring drainage, while clay and loams require wall drainage. If it is possible to install a second, higher floor in the basement of a house, reservoir drainage is installed between the new and old floor in the form of backfilling filter material - gravel, crushed stone, coarse sand.

Pro tip: It is necessary to observe measures against settlement and soil removal when constructing drainage for an already constructed building. The trench should be dug in small sections and immediately backfilled after drainage is installed.

So, we figured out what types of drainage are used in certain situations, and also looked at the features of the arrangement of each type of drainage. Let’s hope that our recommendations and your competent implementation of them will allow you to achieve the required level of dryness in your garden plot and other areas.

Heavy seasonal precipitation and the proximity of aquifers to the ground surface force owners of cottages and country houses to think about combating excess moisture. Its excess can spell serious trouble:
soils oversaturated with moisture become limp, which complicates work and creates difficulties for moving around the site;
due to hydrostatic pressure, moisture intensively penetrates into the pores of the foundation and other building structures, which leads to their partial destruction and reduced reliability, flooding of the basement floors, and deterioration of the indoor microclimate;
During the off-season period, when the air temperature drops below zero degrees at night, the moisture accumulated on the surface of the blind area and steps freezes and turns into ice - which not only contributes to the accelerated destruction of coatings, but most importantly can lead to injuries to people.
water that is not drained from the surface in the autumn-spring period hardens into an impenetrable crust in the upper fertile layer, which not only has a detrimental effect on the lawn and garden plants, but also contributes to the formation of the so-called perched water - water that forms on the surface of the soil, but is not able to percolate into the ground due to a layer of ice. Such waters disappear only after the top layer of the surface has completely thawed; in some cases, the soil does not thaw until the end of May.
The most effective method of control is the installation of a drainage system.

Main tasks of drainage

In the modern understanding, drainage implies the removal of water from the surface or the drainage of groundwater on land plots.
The tasks that the drainage system solves are:
protection of buildings and structures, parts of structures from constant exposure to moisture;
preventing the penetration of moisture into residential and utility rooms;
ensuring the normal condition of sites and paths;
protection of planted plants from siltation;
elimination of the phenomenon of water erosion of the upper fertile layers.
The first 3 of them are solved by wall or ring drainage at home.

What is ring foundation drainage and its difference from wall drainage?

Wall systems are highly efficient and allow for maximum protection of foundations and basements of buildings. They are installed, as a rule, during the construction of a house at the stage of laying buried structures (primarily foundations). Their main feature is their location in close proximity (at a distance of no more than 1 m) to foundations and walls. Most often they are designed in conjunction with waterproofing systems.

When the house has already been built and the construction of a wall drainage system is difficult or impossible, the best solution is ring drainage of the foundation.

This term refers to a trench system in which drains are laid along the entire perimeter of the building at a certain distance (from 1 to 3 m) from the foundation structures.
This design determines the main features of foundation ring drainage systems:
Ease of implementation - the system can be built on its own without the involvement of construction equipment and the use of expensive materials and components;
Specifics of application - ring drainage around the house in soils with high water permeability (for example, sandstones) is most often used;
Mandatory installation requirements - the system is effective only if the conditions for laying depth, etc. are met.

Basic conditions for ring foundation drainage

To reliably protect foundation structures from moisture and basement rooms from flooding, when laying a ring drainage around the house, it is necessary to fulfill the following conditions:
Lowering the groundwater level within the serviced perimeter. It is determined by the depth of the drains, the height of the groundwater level and the height of the capillary rise of moisture in the soil. In practice, foundation ring drainage pipes are located slightly below the calculated reduced groundwater level, and, as a rule, below the base of the building.
Ensuring an effective drainage radius. It determines the permissible distance from the structures to the axis of the drains and depends on the nature of the soil, the size of the foundation, the depth of the drainage pipes and the width of the trench. It should be remembered that laying at a distance less than the calculated one can lead to leaching of soil from under the foundations, and at a greater distance - to a decrease in the efficiency of groundwater drainage.
The functioning of the system taking into account the climatic characteristics of the area. From this point, foundation ring drainage pipes are produced below the soil freezing level typical for the region.

In addition to these, there are other additional requirements, for example, those determined by sanitary rules, which must also be taken into account when designing the system.

Ring drainage device

Ring foundation drainage is a system of buried perforated pipes (drains) laid along the perimeter of the protected building, usually parallel to the foundation structures.

When designing and installing it, the following should be provided:
The movement of liquid through drains is by gravity, which requires laying them with a slope of 2-5 mm per linear meter of the main line.
Connecting the branches of the system in such a way as to eliminate the danger of blockages and provide for the possibility of cleaning the pipes - as a rule, inspection wells (sections of a vertical pipe covered with covers) are installed in places where drains turn.
A drainage line for discharging the liquid collected by the system into a drainage well, natural reservoirs, sewer system collector or other special hydraulic structures.

How to build a ring drainage system at home

The construction of a ring foundation drainage should begin by determining the characteristics of the site. For design, you will need information about groundwater levels and their seasonal rise, the distribution of precipitation in the region, the nature and level of soil freezing, and topography.

In addition, a diagram of the site and adjacent territories is required, indicating the location of neighboring sites, natural reservoirs and springs, sewers and other hydraulic structures (for example, drainage canals), roads and ditches, etc.
It is difficult to obtain all the necessary information on your own; you will have to turn to specialists from a land management organization or hydrogeologists.
Next, a project (plan) of a foundation ring drainage system is drawn up, indicating the places for laying pipes, installing wells, and pipelines for discharging collected moisture.

Based on it, construction begins:

Trenches are dug to a depth corresponding to the estimated depth of the house drainage system pipes and the thickness of the cushion (the trench width is up to 0.5 m; for drainage efficiency and ease of installation, the trench slopes must have an angle of at least 30 degrees).

In places where the direction of pipes changes, wells are installed (the height must correspond to the blind area).

A cushion is placed at the bottom of the trench - a layer of compacted sand and/or coarse crushed stone up to 15 cm thick.

The rock layer is covered with geotextiles with high water permeability, leaving wings on the slopes of the trenches.

A layer of drainage rocks (washed crushed stone, expanded clay, gravel) is laid on the geotextile, and drains (PVC, polyethylene corrugated or metal perforated pipes) are laid.

Cover the pipes with a layer of drainage material.

The structure is covered with geotextile wings and backfilled with sand or crushed stone and backfilled with soil.

Cost of foundation ring drainage

The costs of constructing a ring foundation drainage system consist of the cost of purchasing materials, the cost of excavation and installation work (if they are carried out by contractors). When constructing a ring drainage around a house on your own, you will have to spend about 600-900 rubles per linear meter of construction. Additional costs will be required for hydrogeological analysis of the site, system design, etc.

Specialized construction organizations offer such services at a price of 1,000 to 3,000 rubles per linear meter (the cost of work increases especially significantly with increasing laying depth).

A particularly advantageous option would be to conclude an agreement with an organization that can undertake all types of work - from analysis and design to commissioning, such as Promstok. In this case, fulfillment of all requirements, including those determined by federal and local legislation, and high quality of materials and work are guaranteed.

In a private house there are several places that need to be protected from getting wet from the outside. These are the foundation and buried buildings. Rainwater, all kinds of drains and rising groundwater gradually destroy the monolithic foundations and walls of basements. A properly equipped drainage system around the house can prevent this process from occurring. It is capable of removing excess moisture from structures. Even a very good blind area cannot compare in terms of protection for a house with a installed drainage system. It is highly recommended to install such a system near every house, regardless of the presence of a basement or ground floor.

A high-quality drainage system around the house with your own hands can be made in several options:

Features of different foundation drainage systems

The choice of a specific type of drainage depends on the presence of buried rooms, the depth of groundwater, the composition of the soil on the site and the topography of the site itself. Let's consider what features the drainage system around the house has.

In total, there are 3 types of drainage, which differ in their location and design:

Important: Please note that reservoir drainage does not replace another type of drainage, but only complements it. Therefore, in addition to it, a main drainage system must be installed.

Please note that if you decide to make a ring drainage around the house with your own hands, the system should be located 0.5 m below the foundation level. This arrangement will ensure high-quality drainage of groundwater from the building at any time of the year.

And if you are thinking about this, then you may find our separate material on this topic useful.

Drainage installation

Let's look at how to make a drainage system around the house in two ways.

Manufacturing of wall drainage

Before carrying out the work, it is necessary to prepare the foundation, since the system will be directly adjacent to it.

To do this, the following work is carried out:

1. The foundation from the outside is primed with a special bitumen primer.
2. Bitumen mastic is applied to the dried surface.
3. A reinforcing mesh with 2 x 2 mm cells is glued onto the mastic.
4. The next day, after the mastic has hardened, a second layer of mastic is again applied to the mesh.

The photo shows the drainage system around the house - a trench and inspection wells along the edges

• A collector well is installed to which drainage pipes will be connected. It is located at the lowest point on the site;
• using a laser or construction level, the slope of the trench running near the foundation is ensured towards the drainage basin;
• the bottom of the trenches is covered with a layer of sand of at least 5 cm;
• geotextiles are laid on the sand, the sides of which will subsequently be wrapped overlapping;
• a gravel backfill is created having a thickness of about 10 cm;
• Prepared perforated pipes are laid on the gravel layer. Their slope is ensured at 2 degrees;
• pipes are joined with adapters and corner connectors;
• at the corners of the building, all pipelines enter installed inspection wells;
• Pipes are laid from inspection wells to drain water into a collection well or drainage pit. These pipes are also located in trenches and have a slope;
• The pipes are filled with gravel (about 10 cm) and the entire contents are wrapped in geotextiles. Using synthetic ropes, geotextiles are firmly fixed;
• further backfilling of the trenches to the soil level is carried out with sand or turf soil.

We looked at how to make drainage around a wall-type foundation. Next, we will pay attention to the manufacture of trench drainage, which is even more popular.

Manufacturing of ring drainage

For this type of work you will also need perforated pipes, crushed stone, sand and geotextiles. When a ring drainage system is made around a house, the technology involves digging trenches at a distance of 5-8 m from the foundation of the building to eliminate the possibility of subsidence of the soil around it. The trenches are located around the structure and form a closed system. The depth of the trenches should be such that the drainage passes 50 cm below the foundation level.

Immediately draw a trench (or several trenches) towards the main drainage well. The slope of the trenches is ensured at least 2-3 cm per linear meter. The slope can be adjusted by adding sand in the right places.

• the bottom of the trenches is lined with a layer of sand, and then with geotextiles, the edges of which are wrapped on their walls;
• crushed stone is poured onto the geotextile in a layer of 10 cm;
• Pipes with holes drilled in them are laid out on the crushed stone. It is advisable to use a pipe diameter of at least 10 cm. It is advisable to first wrap all pipes with a layer of geotextile, which will prevent them from clogging;

Tip: Regular PVC pipes used for sewerage are quite suitable. You can drill holes of small diameter in them with a drill, arranging them in a certain order.

• the slope of the pipes is checked, which must be at least 2 degrees;
• At pipe bends, inspection wells are installed, covered with removable covers. The same wells should be installed on long straight sections, in increments of 12 m;
• crushed stone or gravel is poured over the laid pipes in a layer of 20-30 cm;
• the entire “pie” inside the trenches is wrapped with geotextile overlapping;
• the remaining space in the trenches is filled with river sand and covered with turf.

Features of drainage wells

Any drainage around a site or building must be constructed using several inspection wells located at pipe bends. It is in these places that drainage pipes become clogged most often. Through the inspection well, you can monitor the cleanliness of the drains and clean them if necessary. Wells can be purchased or made from any materials. They should have such a width that it is convenient to clean them by placing your hand there.

In addition to several inspection wells, at the lowest point of the site there is collector well, designed to collect all the water flowing through the channels. This is a wider and more voluminous structure, which can be concrete, plastic or metal. Its depth is chosen so that the pipes entering it are located at a considerable distance from the bottom. This makes it possible to periodically clean the well from sediments accumulated at its bottom and allows the well to fill with wastewater. Water can be pumped out from the collection tank by a pump or flow by gravity to designated areas.

By creating a drainage system around the house according to all the rules, you will get rid of the harmful effects of excessive dampness affecting the foundation and recessed areas of the house.

Until now, design organizations,carried out those planning the design of drainage systems (hereinafter referred to as drainages) in Moscow are guided by the “Temporary guidelines for the design of drainages in Moscow ve (N M- 15- 69) » , developed in 1969 “Mosproe who m-1” and “Mosinzhproe who.”

During the practical use of the “Temporary Instructions”, new drainage designs have appeared, based on the use of modern materials, and both positive and negative experience in the design and construction of drainages has been accumulated, which necessitates the development of a new regulatory document.

Application area

The “Guide” is intended for use in the design and construction of drainages of buildings, structures and underground communication channels located in residential microdistricts, as well as for detached buildings and structures.

The “Guidelines” do not apply to the design of shallow road drainages, transport and other special-purpose structures, as well as temporary dewatering during construction work.

a common part

To protect buried parts of buildings (basements, technical undergrounds, pits, etc.), internalquarterly x collectors, communication channels from flooding with groundwater must provide there is drainage and... Con with Drainage structures and waterproofing of the underground part of buildings and structures must be carried out in accordance with SNiP 2.06.15-85,SNiP 2.02.01-83*,MGSN 2.07-97, “Recommendations for the design of waterproofing of underground parts of buildings and structures”, developed by TsNIIPpromzdany in 1996year and the requirements of this “Manual”.

Drainage design should be carried out on the basis of specific data on the hydrogeological conditions of the construction site, the degree of aggressiveness of groundwater to building structures, space-planning and design solutions of protected buildings and structures, as well as the functional purpose of these premises.

Prot And vocapillary waterproofing in walls and coating or painting insulation of vertical wall surfaces,in contact with the ground, must be provided in all cases, regardless of the drainage arrangement.

The installation of drains is mandatory in cases of location :

basement floors ,technical subfields, int. morning and quarterly x collectors, communication channels, etc. below the calculated groundwater level or if the elevation of the floors above the calculated groundwater level is less 50 cm;

floors of exploited basements, intra-block collectors, communication channels in clay and loamy soils, regardless of the presenceI groundwater;

floors of basements located in the zone of capillary humidification, when the appearance of water in the basement is not allowed s grow;

floors of technical undergrounds in clay and loamy soils when they are buried more than 1, 3m from the planning surface of the earth, regardless of the presence of groundwater;

floors of technical undergrounds in clayey and loamy soils when they are buried less than 1, 3m from the planning surface of the earth when the floor is located on the foundation slab, as well as in cases where sand lenses approach the building from the upland side or a thalweg is located from the upland side to the building.

To prevent flooding of soil areas and the flow of water to buildings and structures, in addition to the installation of drainages, it is necessary to provide:

standard soil compaction when backfilling pits and trenches;

as a rule, closed outlets of drains from the roof of buildings;

drainage sch there are open trays with a cross-section≥15×15 see with longitudinal slope,≥1% with open drain outlets;

installation of blind areas for buildings wide≥100see with active cross slope from buildings≥2% to roads or trays;

hermetic sealing of holes in external walls and foundations at the inputs and outputs of utility networks;

organized surface runoff from the territory of the designed facility, which does not impair the drainage of rain and melt water from the adjacent territory.

In cases where, due to low elevations of the existing ground surface, it is not possible to ensure the drainage of surface water or to achieve the required reduction of groundwater, provision should be made for filling the area to the required elevations. If it is impossible to drain drainage water by gravity from individual buildings and structures or a group of buildings, it is necessary to provide for the installation of pumping stations for pumping drainage water.

The design of drainages for new facilities should be carried out taking into account existing or previously designed drainages of adjacent territories y.

If there is a general decrease in the groundwater level in the microdistrict, the marks for the reduced groundwater level should be set at 0, 5m below the floors of basements, technical undergrounds, communication channels and other structures. If a general lowering of the groundwater level is impossible or impractical, local drainage should be provided for individual buildings and structures (or groups of buildings)).

Local drainage, as a rule, should be arranged in cases of significant deepening of underground floors separatelys x buildings if it is impossible to remove drainage water by gravity.

Types of drains

Depending on the location of the drainage in relation to the aquifer, drainages can be of a perfect or imperfect type.

Perfect type drainage is laid on aquifer. Groundwater enters the drainage from above and from the sides. In accordance with these conditions, a perfect type of drainage must have a drainage layer on top and on the sides (see Fig.).

An imperfect type of drainage is laid above the aquifer. Groundwater enters drainages from all sides, so drainage filling must be carried outh closed on all sides (see fig.).

Initial data for drainage design

To draw up a drainage project, the following data and materials are required:

technical report on hydrogeological conditions of construction;

scale plan of the territory 1: 500with existing and planned buildings and underground structures;

relief organization project;

plans and floor marks of basements and subfloors of buildings;

plans, sections and developments of building foundations;

plans ,longitudinal profiles and sections of underground channels.

The technical report on the hydrogeological conditions of construction should contain the characteristics of groundwater, geologicalG o-lithological structure of the site and physical and mechanical properties of soils.

The groundwater characteristics section should indicate:

reasons for the formation and sources of groundwater supply;

groundwater regime and marks of the appeared, established and calculated levels of groundwater, and, if necessary, the height of the zone of capillary soil moisture;

chemical analysis data and conclusion on the aggressiveness of groundwater in relation to concrete and mortar A m.

The geological and lithological section provides a general description of the structure of the site.

The characteristics of the physical and mechanical properties of soils should indicate:

granulometric composition of sandy soils;

filtration coefficients of sandy soils and sandy loams;

porosity and fluid loss coefficients;

angle of repose and bearing capacity of soils.

The conclusion should be accompanied by the main geological sections and soil “columns” from the boreholes, necessary for compiling geological sections along the drainage routes.

If necessary, in difficult hydrogeological conditions for drainage projects of blocks and microdistricts, a hydroisohypsum map and a soil distribution map should be attached to the technical conclusion.

In the case of special requirements for the drainage device caused by the specific operating conditions of the protected premises and structures, these requirements must be set forth by the customer as additional initial materials for drainage design.

General conditions for choosing a drainage system

The drainage system is selected depending on the nature of the protected object and hydrogeological conditions.

When designing new blocks and microdistricts in areas with high groundwater levels, a general drainage scheme must be developed.

The drainage scheme includes drainage systems,ensuring a general decrease in the level of groundwater in the territory of the block (microdistrict), and local drainages to protect individual structures from flooding by groundwater y.

Drainages that ensure a general decrease in groundwater levels include drainages:

head or shore;

systematically

Local drainages include drainages:

annular;

wall;

layers y.

Local drainages also include drainages intended forh protection of individual structures:

drainage of underground channels;

pit drainage;

road drainage;

drainage of backfilled rivers, streams, ravines and ravines;

slope and wall s th drainages;

drainage of underground parts of existing buildings.

Under favorable conditions (in sandy soils, as well as in sandy layers with a large area of ​​their distribution), local drainages can simultaneously contribute to a general decrease in groundwater levels.

In areas where groundwater occurs in sandy soils,Drainage systems should be used to ensure a general decrease in the groundwater level.

In this case, local drainages should be used to protect individual especially buried structures from flooding with groundwater.

In areas where groundwater lies in clayey, loamy and other soils with low water yield, it is necessary to arrange local drainage And.

Local “preventive” drainages should also be installed in the absence of observable groundwater to protect underground structures locatedl agae in clayey and loamy soils.

In areas with a layered aquifer structure, both general drainage systems and local drainages should be installed.

General drainage systems should be installed to drain water-logged sandy layers through which water enters the drained area. In this system, separate local drainages can also be used, with a depression radiusn The new curve covers a significant area of ​​territory. Local drainages must be arranged for underground structures laid in areas where the aquifer is not completely drained by the general drainage system, as well as in places where h possible appearance of perched water.

In built-up areas, during the construction of individual buildings and structures that need protection from groundwater flooding, local drainage must be installed. The design and construction of these drains must take into account their impact on adjacent existing structures.

Head drainage

To drain areas flooded by a flow of groundwater with a recharge area located outside this territory, a head drainage should be installed (see Fig.).

The head drainage must be laid along the upper, in relation to the underground flow, border of the drained area. The drainage route is designated taking into account the location of the building and is carried out, if possible, in places with higher elevations in d support

The head drain should, as a rule, cross the groundwater flow along its entire width.

When the length of the head drainage is less than the width of the underground flow, additional drains should be installed along the lateral boundaries of the drained area in order to intercept groundwater flowing from the side.

If the aquitard is shallow, the head drainage should be laid on the surface of the aquitard (with some penetration into it) in order to completely intercept groundwater, like a perfect type of drainage.

In cases where it is not possible to lay drainage on an aquiclude, and drainage conditions require that the flow of groundwater be completely intercepted, a screen made of a waterproof sheet piling is installed below the drainage, which must be lowered below the aquitard level.

When the aquitard is deep, the head drainage is laid above the aquifer, as an imperfect type of drainage. In this case, it is necessary to calculate the depression curve. If the installation of one head drainage line does not achieve a decrease in the groundwater level to the specified levels, a second drainage line should be laid parallel to the head drainage. The distance between drainages is determined by calculation.

If the part of the aquifer located above the drainage consists of sandy soils with a filtration coefficient of less than 5m /from ut ki, the lower part of the drainage trench must be filled with sand with a filtration coefficient of at least 5 m/day (see fig.).

The height of sand filling is 0,6 - 0,7H, where: H is the height from the bottom of the drainage trench to the unreduced design groundwater level.

If part of the aquifer located above the drainage has a layered structure, with alternating layers of sand and loam, backfill the drainage trench with sand with a filtration coefficient of at least5m/day must be made on 30see above for the unreduced design groundwater level.

Backfilling with sand can be carried out over the entire width of the vertical trenchl with a thin or inclined prism, with a thickness of at least 30see. For perfect type head drainage, when the aquifer does not have clay, loamy and sandy loam layers, a sand prism can be installed only on one side of the trench (from the side of the water inflow).

If the head drainage is laid in the thickness of relatively weakly permeable soils, underlying well-permeable soils, a combined drainage should be installed, consisting of a horizontal drain and vertical self-flowing wells (see Fig.).

Vertical wells must be connected by their base to the permeable soils of the aquifer, and by their upper part to the inner layer of the horizontal drain bedding.

For draining coastal areas that are flooded due to backwater in rivers and reservoirs,Coastal drainage should be installed (see Fig.), where the symbols are: M G - low-water horizon of the reservoir, G P B is the horizon of backed-up waters of the reservoir.

Coastal drainage is laid parallel to the shore of the reservoir and laid below the normally supported horizon (NP D) a reservoir by an amount determined by calculation.

If necessary, head and bank drainages can be used in combination with other drainage systems.

Systematic drainage

In areas where groundwater does not have a clearly defined flow direction, and the aquifer is composed of sandy soils or has a layered structure with open sand layers, systematic drainage should be arranged (see Fig.).

The distance between systematic drainage drains and their depth are determined by calculation.

In urban conditions, systematic drainage can be arranged in combination with local drainage. In this case, when designing individual drains, it is necessary to decide whether they can be one and the sameV temporary use as local drainage, protecting individual structures and as elements of systematic drainage, ensuring a general decrease in the groundwater level in the drained area.

When laying drains for systematic drainage in the thickness of soil with weak water permeability, underlying well-permeable soils, combined drainage should be used, consisting of horizontal drains with vertical,self-flowing wells (see fig.).

In areas flooded by groundwater flows, the recharge area of ​​which also covers the drained area, head and systematic drainage should be used together.

Ring drainage

To protect basements and subfloors of detached buildings or a group of buildings from flooding with groundwater, when they are located in aquiferous sandy soils, ring drains should be installed (see Fig.).

Ring drainages should also be installed to protect especially damaged basements in new neighborhoods and microdistricts when the depth of the groundwater level drop is insufficient by the general drainage system of the territory.

With good water permeability of sandy soils, as well as when laying drainage on an aquifer,it is possible to arrange a common ring drainage for a group of neighboring buildings.

With a clearly expressed one-way influx of groundwater, drainage can be arranged in the form of an open circuit.l tsa according to the type of head drainage.

Ring drainage must be laid below the floor of the protected structure to a depth,determined by calculation.

If the building is large or when several buildings are protected by one drainage, as well as in the case of special requirements for the reduction of groundwater under the protected structure, the depth of the drainage is taken in accordance with the calculation, in which the excess of the reduced groundwater level in the center of the ring drainage contour must be determined above the water level in the drain. If the drainage depth is insufficient, intermediate “cut” drains should be installed.

Ring drainage should be laid at a distance 5 - 8m from the wall of the building. With a smaller distance or greater depth of drainage, it is necessary to take measures against the removal,weakening and settlement of the soil under the building foundation I

Wall drainage

To protect basements and subfloors of buildings laid in clay and loamy soils from groundwater, wall drainages should be installed.

Wall “preventive” drainages must also be installed in the absence of groundwater in the area of ​​basements and underground areas located in clayey and loamy soils.

If the aquifer has a layered structure, wall or ring drains should be installed to protect basements and subfloors of buildings, depending on local conditions.

If individual parts of the building are located in areas with different geological conditions, in these areas it can be used as a ring,and wall drainage.

Wall drainage is laid along the contour of the building from the outsides. The distance between the drainage and the wall of the building is determined by the width of the building foundations and the placement of drainage inspection wells.

Wall drainage, as a rule, should be laid at levels not lower than the bottom of the strip foundation or the base of the foundation slabs s.

If the foundations are laid at a great depth from the basement floor level, wall drainage can be laid above the base of the foundations, provided that measures are taken to prevent drainage subsidence.

Installation of wall drainage using modern polymer filter materials, in particular using the “Dreniz” casing», reduces construction costs by saving sand.

The Dreniz shell consists of a two-layer structure: a special profile sheet made of polymer material (polyethylene, polypropylene, polyvinAnd lchloride) and non-woven geotextile filter material, fastened together by welding or waterproof glue. Shell sheets"Dreniz" overlap each other Art.

The technology for using this material is indicatedV Instructions VSN 35-95.

Formative drainage

To protect against flooding by groundwater the basements and subfloors of buildings located in difficult hydrogeological conditions, such as: in aquifers of high thickness, with a layered structure of the aquifer, in the presence of pressurized groundwater, etc., as well as in the case of insufficient effectiveness of using ring or wall drainage, reservoir drainage should be installed (see Fig.).

In aquifers of large thickness, it is necessary to first calculate the possible decrease in the groundwater level in the center of the ring drainage contour. In case of insufficient reduction of groundwater level, it is necessary to apply layers s th drainage.

If the structure of the aquifer is complex, with changes in its composition and water permeability (in plan and section), as well as in the presence of watered closed zones and lenses under the basement floor, reservoir drainages are installed.

In the presence of pressurized groundwater, ring or reservoir drainage should be used depending on local hydrogeological conditions with calculation justification.

To protect basements and structures in which, due to operating conditions, the appearance of dampness is not allowed, when laying these premises in the zone of capillary soil moisture, formation drainage should be installed.

Layered “preventive” drainages for such premises and structures located in clayey and loamy soils are also recommended to be provided in the absence of observable groundwater.

Reservoir drainages are installed in combination with tubular drainages (ring and wall).

To connect reservoir drainage with external tubular drainage, a tubular drainage is laid through the foundations of the building.

For underground buildings with foundations on pile grillages, reservoir drainage can be installed in combination with a single-line drainage laid under the building.

Drainage of underground channels

To protect heating network channels and collectors of underground structures from flooding by groundwater when laying them in aquiferous soils, it is necessary to install linear accompanying drainages.

“Preventive” (accompanying) drainages should be installed in clayey and loamy soils.

The accompanying drainage must be laid on 0,3 - 0,7 m below the base of the canal.

The accompanying drainage should be laid on one side of the channel at a distance 0, 7 - 1, 0m from the outer edge of the channel. Distance 0, 7m is necessary to place inspection wells.

When installing passage channels, drainage can be laid under the channel along its axis. In this case, special inspection rooms should be installed on the drainage.l boats with hatches sealed in the bottom of the canal.

In the case of laying the foundation of a canal on clay and loamy soils, as well as on sandy soils with a filtration coefficient of less than5m/day, under the base of the canal it is necessary to arrange layers s th drainage in the form of a continuous sand layer.

The reservoir drainage must be connected to the drainage bedding of the accompanying tubular drainage.

When constructing channels in clay and loamy soils,V soils with a layered structure, as well as in sandy soils with a filtration coefficient of less than 5m/day, both sides of the canal must be filled V vertical or inclined prisms made of sand with a filtration coefficient of at least e5 m/day.

Sand prisms are intended to receive water flowing from the sides and are arranged similarly to the sand prisms of the head and wall drainages.

Drainage of pits and buried parts of basements

Drainage of pits and recessed parts of basements must be decided in each case depending on local hydrogeological conditions and adopted building designs.

deepening of the lower section of the drainage, when buried rooms and pits are located at its lower part, counting along the flow of water in the drainage;

a general decrease in drainage when laying drainage and protected structures in sandy soils;

dividing the general drainage into separate parts with independent outlets; installation of additional local drainages.

When draining individual pitsV and buried premises, it is necessary to pay special attention to measures against the removal of soil from under the foundations of the building.

When installing ring drains, the foundations of the building can be laid slightly above the drainage. The excess of the building foundations above the drainage and the distance of the drainage from the building must be checked taking into account the angle of internal friction of the soil according to the formula:

Where

l min - the smallest distance of the drain axis from the wall of the building in m,

b - widened And e of the building foundation in m,

B is the width of the drainage trench in m,

H is the depth of the drain in m,

h - foundation depth in m,

φ - angle of internal friction of the soil.

When laying drainage below the foundation of buildings in order to avoid soil suffusion, special attention should be paid to the correct selection and installation of drainage fills, to the quality of sealing of seams and holes in wells,as well as for measures to prevent the removal of soil when digging drainage trenches.

If there is a large drop in the groundwater horizon under foundations (existing and planned), the soil settlement should be calculated.

When constructing differences in drainage within the zone of influence of the lower drain, the measures listed above should also be taken into account.

Drop s Wells must be constructed with careful sealing of all seams and holes.

Local drainage for individual pits is recommended to be arranged according to the type of reservoir drainage.

Other types of drainage

In some cases, the required reduction in groundwater levels can be achieved by a system of general drainage of the territory (head and systematic drainage).

Drains can be laid together with gutters (see fig.).

When filling rivers, streams, ravines and ravines, which are natural drainage of groundwater, in addition to collectors for draining surface water, it is necessary to install drainages to receive groundwater.

Drains must be provided with a connection to the aquifer on both sides of the drainage collector. With a large influx of groundwater,and also when laying a collector on clay and loam, two drains are laid, placing them on both sides of the collector.

If the groundwater inflow is low and the drainage collector is located in sandy soils, one drain can be laid, positioning it on the side of the larger water inflow. If sandy soils have a filtration coefficient less than5m/day, a layer must be constructed under the base of the reservoir s th drainage in the form of a continuous layer or individual prisms.

When the aquifer wedges out on slopes and slopes, it is necessaryd imo arrange intercepting drainage And.

Intercepting drains are laid at a depth no less than the freezing depth and are arranged like a head drain.

When aquifers are not clearly expressed and groundwater wedges out over the entire area of ​​the slope, speciale slope drainages.

When installing retaining walls, in places where groundwater wedges out, a wall is installedth drainage. Zast oh This drainage is a continuous backfill of filter material laid behind the wall. If the length is short, wall drainage can be installed without a pipe. For significant lengths, it is recommended to install tubular drainage with drainage bedding.

To catch springs that wedge out on a slope, capture wells are installed.

Sloping and walls Drainages and capture wells must have secured water outlets.

To protect existing basements and subfloors of buildings, the type of drainage is chosen on a case-by-case basis, guided by local conditions.

In sandy soils, ring and head drainages are installed.

In clay and loamy soils at deepO When laying foundations, wall drainage is arranged, provided that such a solution is allowed by the design of the foundations and walls of the building.

Plastov m drainage is arranged in case,when a second floor can be installed in the basement at higher elevations. In this case, a layer of filter material (coarse sand with gravel or crushed stone prisms) is poured between the old and new floors and connected to an external tubular drainage, as in conventional reservoir drainages.

When designing and constructing drainages for existing buildings, measures must be taken against the removal and subsidence of soil.

In these cases, the excavation of the drainage trench should be carried out in short sections with immediate laying of the drainage and backfilling of the trench.

Drainage route

The routes of ring, wall and accompanying drainages are determined by reference to the protected structure.

The routes of head and systematic drainages are determined in accordance with hydrogeological conditions and building conditions.

When laying drainage below the base of the foundations of adjacent structures and networks, the distances between them must be checked taking into account the anglel and the natural slope of the soil from the edge of the base of the foundation of the structure (or network) to the edge of the drainage trench (see).

Longitudinal drainage profile

The depth of drainage should be no less than the depth of soil freezing.

The depth of the head, ring and systematic drainages is determined by hydraulic calculations and the depth of the protected buildings and structures.

The depth of wall and associated drainages is determined in accordance with the depth of the protected structures.

The greatest drainage slopes should be determined based on the maximum permissible water flow rate in the pipes- 1, 0 m/s k.

Placement of inspection wells

Viewings e wells should be installed in places where the route turns and slopes change, at drops, as well as between uh these points at large distances.

On straight drainage sections, the normal distance between inspection wells is40m. The greatest distance between drainage inspection wells is 50 m.

At drainage turns near building ledges and at chambers on canals, the installation of inspection wells is not necessary, provided that the distance from the turn to the nearest inspection well is no more20m. In the case where the drainage makes several turns in the area between inspection wells, inspection wells are installed through one turn.

Release device

Water is released from drains into drains, reservoirs and ravine And.

The connection of drains to gutters, as a rule, should be carried out higher w ate gi of the drain. If drainage is connected below went s gi drain pipes, Location on When drainage is released, a check valve must be provided. It is not recommended to connect drainage to drains below the water level in the latter during periods of excess 3 times a year.

When released into a reservoir, the drainage must be laid above the water horizon in the reservoir during a flood. In case of a short-term rise in the horizon of a reservoir, drainage, if necessary, can be laid below the flood horizon, provided that the drainage release is equipped with a check valve.

The mouth section of the drainage outlet into the reservoir must be buried below the water horizon to the thickness of the ice cover with the installation of a drop well.

If it is impossible to release water from the drainage by gravity, it is necessary to provide a pumping station (installation) for pumping drainage V od, working in automatic mode.

Combining drainage with drainage

When designing drainage, you should consider the option ofTo fix it together with the drain (see fig.).

If the drainage depth is sufficient, the drainage should be located above the drainage in the same vertical plane with drainage water discharged into each inspection well of the drainage system. The clear distance between the drainage and drainage pipes must be at least 5cm.

If it is impossible, due to the depth of the installation, to place the drainage above the drain, the drainage should be laid in parallel in the same trench with the drain.

Pipes

Asbestos-cement pipes should be used for drainage.

The exception is drainage laid in groundwater, which is aggressive to concrete and Portland cement mortars. In this case, plastic pipes should be used for drainage.

The permissible maximum backfill depths to the top of the pipe drainage depend on the design resistance of the load-bearing soil, pipe material, pipe laying methods (natural or artificial foundation) and trench backfill, as well as other factors.

Necessary data on the use of asbestos st cement x pipes are available in the album SK 2111- 89, and through plastic pipes - in the SK album 2103- 84.

Water inlet openings in pipes should be arranged in the form of cuts with a width 3 - 5mm. The length of the cut should be equal to half the diameter of the pipe. The cuts are made on both sides of the pipe in a checkerboard pattern. Distance between holes on one side - 50see. There is an option with drilling water inlet holes (see fig.,).

When laying pipes, it is necessary to ensure that the cuts are on the side of the pipe; the top and bottom of the pipe should be without cuts.

Asbestos-cement pipes are connected with couplings.

When using polyvinyl chloride s x pipes (P V X) water intake holes are made similarly to asbestos-cement s m pipes. Corrugated drainage pipe made of polyethylene (HDPE) is produced with ready-made water inlet holes (see fig.).

Drainage structures and drainage filters

Drainage bedding, in accordance with the composition of the drained soils, is arranged in single or double layers.

When placing drainage in sand, gravel sheets x, large and medium size (with an average particle diameter 0, 3 - 0, 4mm and larger) arrange single-layer gravel or crushed stone.

When drainage is located in medium-sized sands with an average particle diameter less than 0, 3 - 0, 4mm, as well as in small and p ylevat s In sands, sandy loams and with a layered structure of the aquifer, two-layer bedding is arranged (see Fig. 20). The inner layer of the sprinkling is made of crushed stone, and the outer layer of the sprinkling is made of sand.

Drainage fill materials must meet the requirements for materials for hydraulic structures.

For inner layer dren gravel is used as a filling coating, and in the absence of e G o - crushed stone of igneous rocks (granite, syenite, gabbro, liparite, basalt, diabase, etc.) or especially durable varieties of sedimentary rocks (siliceous limestones and well-cemented non-weathering sandstones).

Sands, which are a product of weathering of igneous rocks, are used for the outer layer of bedding.

Materials for drainage bedding must be clean and not contain more than 3- 5% by weight of particles with a diameter less than 0.1 mm.

The composition of drainage fills is selected according to special schedules depending on the type of filter and the composition of the drained soil.

Drains should be laid in drained trenches. In sandy soils, water reduction using wellpoints is used. When laying drainage on an aquifer, dewatering with the installation of construction drains, freezing or chemical consolidation of soils are used.

Imperfect type drainage pipes are laid on the lower layers of drainage fill, which in turn are laid directly on the bottom of the trench.

For perfect type drainages, the base (bottom of the trench) is strengthened with crushed stone compacted into the ground, and the pipes are laid on layers of sand a thickness of 5cm.

In weak soils with insufficient bearing capacity, drainage should be laid on an artificial foundation.

Drainage bedding can have a rectangular or trapezoidal shape in cross section.

Rectangular sprinklings are arranged using inventory boards.

Sprinkles of a trapezoidal shape are poured without shields with slopes 1:1.

The thickness of one layer of drainage coating must be at least 15cm.

Pipe filters

Instead of installing drainage from pipes with gravel sch baby As a filter for preventive drainage, pipe filters made of porous concrete or other material can be used. The area and conditions of use of pipe filters are determined by special instructions.

Wells

On Wells are installed in tubular drainages.

Dl I protection from h To prevent weeds, wells must be equipped with second covers.

Drop s Drainage wells must have a water feature.

Sand prisms

When laying drainage in sandy soils With filtration coefficient less5m/day, as well as in soils with a layered structure, part of the trench above the drainage is covered with sand. The filled sand prism must have a filtration coefficient of at least 5 m/day

A trench dug in sandy soils is backfilled with sand to a height 0, 6 - 0, 7H, where H is the height from the bottom of the trench to the groundwater level, but not less 15see above the top of the drainage bedding. In soils with a layered structure, the trench is filled with sand on 30see above the groundwater level (see Fig.).

Filter wells

If the structure of the aquifer is heterogeneous, when a horizontal drain runs in the upper less permeable layer, and a more permeable layer is located below, a combined drainage is arranged, consisting of a horizontal drain and vertical self-flowing filter wells (see Fig.).

Drilling of vertical filter wells can be done hydraulically (by immersion using a submersibleV a) or by drilling method m. In these cases, filter wells are constructed structurally similar to tube wells for vertical drainage. The mouth (upper end of the tube well) is located below the general unreduced groundwater level and is embedded in the bottom of the drainage inspection well. The mark of the mouth of the tube well should be higher than the mark of the horizontal drain tray on 15cm. At shallow depths, installation of filter wells can be done in an open way. For this purpose, wells are opened from the bottom of the horizontal drainage trench, in which pipes (asbestos) are installed vertically cement e or plastic) filled with gravel or crushed stone. The space between the vertical pipe and the ground is filled with coarse sand. The lower end of the vertical pipe enters the layer of gravel or crushed stone at the bottom of the well A. The upper end of the pipe mates with the inner layer of the horizontal drain.

Reservoir drainage design

Plastov s th drainage is used to protect building basements, pits and canals in cases where tubular drainage alone does not provide the necessary drainage effect.

Reservoir drainage is arranged in the form of a layer of sand poured along the bottom of a pit under a building or a trench for a canal.

The layer of sand is cut through in the transverse direction with prisms made of gravel or crushed stone.

Reservoir drainage must be protected from clogging during constructionA. When constructing floors and foundations using the wet method (using monolithic concrete and cement mortars), it is necessary to close the layers s and drainage with insulating material (glassine, etc.) P.).

Gravel (or crushed stone) prisms must have a height of at least 20cm.

Distance between prisms -6÷12 m (depending on hydrogeological conditions). Prisms are being laid, usually , in the middle between the transverse foundations of the building.

With a large influx of water or for particularly critical reservoir structuress th drainage can be two-layer over the entire area with a bottom layer of sand and a top layer of gravel and whether crushed stone.

If the width of the protected structure is small and the influx of water is limited, in particular under underground channels, reservoir drainage can be constructed from a single layer of sand or crushed stone.

The thickness of reservoir drainage under buildings must be at least30cm, and under the channels - no less 15 cm.

In some cases, with a large drainage area or special requirements for reducing the capillary saturation zone, the thickness and design of reservoir drainage are determined by calculation.

Reservoir drainage should extend beyond the outer walls of the structure, and, if necessary, be poured along the slope of the pit (trench).

The reservoir drainage must be connected to a ring, wall or accompanying tubular drainage.

For large areas And subs. In large rooms, additional tubular drains should be laid under the floor of the room.

In the undergrounds of buildings erected on pile foundations, reservoir drainage can be arranged in combination with a single-line tubular drainage located under the underground m

Pumping stations (installations) for pumping out drainage water

The depth of the underground premises of residential and public buildings and structures does not always allow drainage water to be directed by gravity into the storm sewer. In this case, it is necessary to install drainage pumping stations. When designing drainage pumping stations, the following should be taken into account:

The installation of free-standing pumping stations (installations), as a rule, is not economically feasible, because the costs of their construction and operation will be significantly higher than those built into basements;

pumping installations should mainly be located in buildings from which it is not possible to direct drainage water into the storm sewer (gutter) by gravity;

During a feasibility study, it is possible to install one pumping station for pumping drainage water from several buildings. Ifh The data will belong to different owners; to resolve this issue, it is necessary to obtain an appropriate document on shared participation in the construction and operation of a common pumping station, drawn up in the prescribed manner.

When deciding on the placement of pumping stations for pumping drainage water, the priority is to comply with permissible levels of noise and vibration from pumping units and pipelines in apartments of residential buildings and public premises.

Pumping installations should not be located: under residential apartments, children's or group rooms of kindergartens and nurseries, classrooms of secondary schools, hospital premises, workrooms of administrative buildings, classrooms of educational institutions and other similar premises.

In projects, it is necessary to make appropriate noise and vibration calculations that determine the choice of technical measures to ensure compliance with the requirements for permissible noise and vibration levels in residential and public areas of buildings in accordance withMGSN 2.04-97 , manuals for MGSN 2.04-97 “Design of protection from noise and vibration of engineering equipment in residential and public buildings” and “Design of sound insulation of enclosing structures of residential and public buildings.”

The flow rates of drainage water sent to the pumping station must be determined specifically for each facility.

As a rule, the installation should include two pumping units, of which one is a reserve one. If justified, installation of a large number of pumps is allowed. When there is limited space to accommodate a pumping station, it is most advisable to use submersible pumps.

The drainage pumping station must have a special room necessary to accommodate the receiving tank, pumping units and other equipment.

Only personnel servicing the installed equipment should have access to the pumping station.

The operation of pumping stations should be provided in automatic mode.

Capacity of receiving tanks withl should be determined depending on the calculated second flow rate of drainage water, the performance of the selected pump or pumps and the permissible frequency of switching on the pump electric motor, but not less 5- its maximum minute performance (for domestic pumps). The maximum number of starts per hour for imported pumps must be indicated in the technical documentation of the manufacturer. If this data is not available, a corresponding request should be made.

To reduce the frequency of pump activation, their alternate operation can be provided. In this case, it is necessary to provide3-th reserve pump, which can be stored in a warehouse. Considering that drainage water, as a rule, is relatively clean, it is possible not to provide a special pipeline for stirring up the sediment in the tank. For contaminated water or if it is necessary to regulate the flow of wastewater pumped by pumps, the specified pipeline should be provided.

To automate and dispatch the operation of pumping units, appropriate water levels are assigned in the receiving tank of the pumping station.

Worker and reserve activation levels var pumps must be installed below the supply pipeline tray. In this case, the activation level of the backup pump is set higher than the working one, because it should turn on not only during an emergency stop of the working pump, but also when the influx of water increases and, accordingly, its level in the tank increases (i.e. if the productivity of the working pump is less than the increased influx of wastewater).

In the event of a further increase in the water level due to an emergency stop of the pumps or for other reasons, an upper emergency level is assigned, upon reaching which an alarm is generated.

Upper AvaR level usually taken at the elevation of the supply pipeline tray.

Pump shutdown level must be at a distance of at least 2D in from the bottom of the suction pipe (inlet), and the inlet must be located at least 0.8D in from the bottom of the tank A.

These rules l and it is necessary to comply T b for a favorable supply of water to the vertical suction pipeline and to avoid the entry of air into it.

Lower emergency at level is taken in the interval between the pump shut-off level and the inlet of the suction pipelines.

When applied to a blade installations x horizontal or vertical pumps, the geometric suction height of the pumps must be taken into account.

Each pump must haveV oh suction pipe.

Suction pipes must be sealed. Welded joints are the most preferred.

To prevent the formation of water in the suction pipeh stuffy bags, the pipeline is laid with a rise towards the pump (slope of at least 0, 005). For the same reason, when transitioning from one diameter to another in horizontal sections, only “oblique” transitions with a horizontal upper generatrix (eccentric transition) are used.

Pressure pipelines, after installing check valves and gate valves on them, as a rule, should be combined into one pipeline.

When using submersible pumps, the lower shutdown level must be taken not lower than that specified in the technical documentation of the manufacturer.

Notes :

1.In Fig. and examples of solutions for wall drainage using drainage systems are presented.“DRENIZ” shells and drainage on a pile foundation with filling of the sinuses with sand.

2. It is recommended to use methods for hydrogeological and hydraulic calculations of drainage from the sources given in the appendix.

MGSN 2.07-97 “Foundations, foundations and underground structures”

VSN-35-95 “Instructions for the technology of using polymer filter shells to protect underground parts of buildings and structures from flooding with groundwater”, Research Institute M acute

Album No. 84 Institute Mosinzhproekt "Drainages for l I drain urban areas and protect underground structures"

Album SK 2111 - 89Institute Mosinzhproekt “Underground free-flow pipelines made of asbestos-cement, ceramic and cast iron pipes”

Album SK 2103 - 84Mosinzh Institute project “Underground free-flow pipelines made of plastic pipes”

Designer's Handbook "Complex foundations and foundations" M., 1969G.

Abramov S .TO . "Underground drainage in industrial and civil construction" M., 1967

Degtyarev B. M. and others. “Protection of the foundations of buildings and structures from the effects of underground water" Stroyizdat, 1985

MGSN 2.04-97 “Permissible levels of noise, vibration and requirements for sound insulation in residential and public buildings”

Ring drainage of a building foundation is one of the types of closed drainage systems. In this article we will look at the conditions under which drainage around the house is necessary and the procedure for installing the drainage system. We will also show you how to calculate ring drainage.

Ring drainage around the house: construction conditions

1. Protection of basements and subfloors of buildings built in aquiferous sandy soils from flooding with groundwater.

2. Protection of excessively deep basements in new microdistricts with insufficient reduction of groundwater levels by the general drainage network of the site.

3. If sandy soil drains water well, you can make a ring drainage for several houses nearby.

4. If the one-way inflow of groundwater is pronounced, the drainage can be made open, head.

When calculating the depth, length and slope of pipes in a given drainage system, the following factors must be taken into account:

1. Depth of foundation.

the ring drainage should be at least thirty to fifty centimeters below its base.

2. The slope of the drainage pipe must be at least one percent towards the catchment or spillway (this is one centimeter per linear meter).

Therefore, you need to determine in advance where the lowest point of the system will be. That is, where the collected water will go. To do this, measure the distance between the top point of the drainage system and the bottom, after which a one percent slope is set. As a rule, the highest drainage point coincides with the highest point of the site. This must be a certain corner of the building.

If the terrain is relatively flat, then when constructing a collector well (a collection point for collected water), they are guided by considerations of convenience and expediency.

3. The perimeter of the building and the distance to the drainage area.

Let's say a collector well is installed ten meters from the house. The width of the trench is five meters. Length - seven. We count: 5+7+10 = 22 meters.

We calculate the permissible slope between the top and bottom points. We take one percent of twenty-two meters. The result is twenty-two centimeters. This is the maximum difference between the farthest point of the drainage system and the top of the well.

4. Distance from the foundation surface to the trench wall.

The foundation ring drain should be located five to eight meters from the house. If for some reason the drainage network needs to be made closer, it is important to properly waterproof the foundation surface. Plus protect the structure from settlement, weakening or removal of soil under the foundation.

Scheme of ring foundation drainage:

Construction of the ring system

1. We dig a trench around the perimeter of the building.

2. Pour a layer of sand (approximately five centimeters) onto the bottom and tamp it down. We keep the slope. We lay geotextile fabric. So that its edges are enough to wrap the pipe with gravel. Pour gravel in a fraction of at least five centimeters.

You can use a special perforated one. Or a standard plastic sewer pipe with self-made holes. There must be holes. Through them, water will penetrate the pipes and flow by gravity into the collector well.

4. Sprinkle the pipe on all sides with gravel. Then we cover it with geotextiles. So that one edge covers the other. We fix the winding with twine made of polypropylene or any other non-rotting material. It is important that there are no free spaces through which sand will get into the pipe and clog the holes.

5. Fill the wrapped pipe with coarse river sand or gravel. These materials easily allow water to pass through, do not swell in the cold, and do not retain liquid. Accordingly, an additional filter will be created.

On top of the sand coating is soil.

When constructing any drainage system, it is mandatory to equip inspection intermediate wells. There will need to be two of them around the building.

Thus, the ring foundation drainage is a closed deep drainage system that removes groundwater from the building.