RU2798218C1 - Tube drainage of combined design - Google Patents

Abstract

FIELD: hydraulic engineering.

SUBSTANCE: invention can be used as a drainage device for earth dams and embankment dams. In the method of erecting tubular drainage of earthworks, including the intake and discharge parts, consisting of drainage perforated pipes and flexible mattresses, the receiving part is made of drainage perforated pipes 1 with stiffening rings put on pipes 1 at a distance from each other, geomats 3 are wrapped in layers around drainage pipes 1 and between the stiffening rings, with a geomat thickness equal to the height of the stiffening ring ribs, which, together with perforated pipe 1, form a water-receiving part of the drainage, around which a protective sheath of gabion mesh 5 is wrapped. The outlet part is made of flexible cylindrical mattresses 7, which are made of perforated pipes wrapped around with geomats and geogrid, which are laid in dense rows 6 from the water intake part of the drainage in the direction of the filtration flow towards the downstream of the structure at a certain distance from each other.

EFFECT: tubular drainage can be effectively used in the flat sections of rivers during the construction and reconstruction of earth dams and embankment dams in areas where there is not enough stone and gravel material, as well as in hard-to-reach places where the delivery of construction equipment is difficult.

1 cl, 5 dwg

Description

The invention relates to hydraulic engineering and can be used as a drainage device for earth dams and embankment dams.

A well-known technical solution is the tubular drainage of earthen dams and dams [1], made of perforated concrete or asbestos-cement pipes, laid with a slope parallel to the slope foot and sprinkled with a return filter. The main disadvantages of this technical solution are:

- the need for a large amount of stone and sand-gravel material;

- the complexity of the work on laying return filters around the pipe;

- low work efficiency.

A relatively close technical solution is "Tubular drainage" [2], containing perforated drainage pipes with stiffening rings and flexible mattresses laid around the pipes and consisting of mesh shells and dense rows of light fascias wrapped in a geonet, and a discharge part made of similar mattresses and directed along the slope towards the river bed. The main disadvantages of this technical solution are:

- low efficiency due to the use of light reed fascias for the manufacture of flexible mattresses, which is a natural material and grows only in a water-saturated environment of flat areas, and has a limited service life;

- low throughput of flexible mattresses made of light fascias of the outlet part of the drainage, due to the lack of drainage pipes in the mattresses.

The purpose of the invention is to improve the efficiency of the drainage. This goal is achieved by the fact that the tubular drainage containing the intake and discharge parts is made of a combined design, where the intake part is made of perforated drainage pipes with stiffening rings put on pipes at a distance from each other, geomats are wrapped around the collecting pipes and between the stiffening rings. , with a thickness equal to the height of the ribs of the stiffening rings, which, together with the perforated pipe, form the water intake part of the drainage, around which a protective sheath of gabion mesh is arranged, and the outlet part is made of flexible cylindrical mattresses, which are made of perforated pipes wrapped around with geomats and geogrid, and which laid in dense rows from the water intake part of the drainage in the direction of the filtration flow towards the downstream of the structure.

In FIG. 1. shows a cross-section of an earthwork (dam or dam) with tubular drainage; in fig. 2 - plan of a fragment of a horizontal section of the drainage, in Fig. 3 - water intake perforated pipe with rings (ribs) of stiffness in a perspective view; in fig. 4 - flexible mattress; in fig. 5 - geomat.

Tubular drainage consists of water collection perforated pipes 1 with stiffening rings 2, geomat 3 wrapped in layers around pipes 1 between stiffening rings 2, which, together with pipes 1, form a water intake part 4 of the drainage, around which a protective sheath of gabion mesh 5 is arranged. The outlet part of the drainage is made from densely packed rows 6 located at a certain distance from each other from flexible cylindrical mattresses 7, consisting of perforated pipes 8 and geomat 3, wrapped in a geogrid 9. In the downstream at the end of the outlet parts of the drainage under the outlet parts of the flexible mattresses 7, stone backfills are arranged 10 of gravel and jackdaws. Tubular drainage is built as follows. First, before the construction (reconstruction) of an earthen dam (or dam) at the base of the downstream slope, just above the bottom of the design bureau, a trench is developed according to the overall dimensions of the drainage. A mesh shell 6 (gabion mesh) is laid out along the bottom of the trench, on top of which perforated drainage pipes 1 with stiffening rings 2 are laid, between which geomats 3 are tightly wrapped in layers, which, together with pipes 1, form a water intake part, around which a mesh shell of gabion mesh 5 and attached to the rings (ribs) stiffness 2 (made of polymeric materials). Further, from the drainage perforated pipes 1 at a certain distance from each other and with a slope towards the downstream (NB), trenches 1-2 m wide are laid, filled with dense rows 6 of flexible mattresses 7, forming the drainage part of the drainage, the thickness of the mattresses is 0, 3-0.5 m. The distance between rows 6 can be no more than 8-10 m, taken from the condition of ensuring the normal operation of the tubular drainage. At the end of the flexible mattresses 7 at the base of the tailpipe, an erosion pit is developed and a stone backfill 10 is arranged. After that, a downstream slope of an earthen structure (dam or dam) is erected (completed) on top of the assembled drainage complex. At the same time, the width of the drainage mattress trenches and the distance between them are taken depending on the maximum possible flow rate of the filtration flow. A mattress trench 1 m wide and 0.3 m thick, which runs with a slope of 0.05, allows water flow up to 50 l/s. At the same time, it is necessary to observe the main condition for the normal operation of tubular drainage: the maximum possible water level in the NB must always be below the mark of the bottom of the drainage pipe 1, i.e. there should be no water level backwater from the side of the NB.

Tubular drainage works as follows. Filtration water, moving under the action of hydrostatic pressure from the upstream side (WB) through the pores of the soil of the body of the dam or dam, enters the zone of the water intake part 4 of the drainage. Further, geomats 3 freely accept water due to their high water permeability and pass through the slotted holes into the drainage (drainage) pipe 1. And when pipe 1 is filled to the middle of its section, water easily flows out of pipe 1 into the drainage part 6 - into the discharge rows of flexible mattresses 7, which, through perforated pipes 8 and geomats 3, rapidly drain the filtered water into the NB (due to the good slope and gradient of the filtration flow). In the absence of a water level in the NB, a more efficient operation of the drainage is ensured. Therefore, the drainage of the proposed design is recommended to be used in medium and low-pressure earth dams and embankment dams, when there is no water in the NB under normal operating conditions, or when there is a small water level in the NB, which cannot affect the operation of the drainage. The main soil load above the perforated drainage pipes 1 perceives the stiffening rings 2 and the mesh shell 5. Therefore, the geomats 3 of the water intake part 4 will always work under normal conditions and the intake of seepage water will be provided quite reliably. Above the drainage part 6, consisting of flexible mattresses 7, there is a small layer of soil, which does not significantly affect their throughput. The efficiency of the drainage mattresses 7 is increased if sandy or sandy-gravelly soil is laid on top of them.

In the manufacture of drainage, the main filtration material is geomat - a sufficiently resistant and durable artificial material that works effectively in the aquatic environment and is a highly draining material. This excludes the removal and penetration of small particles of soil into the drainage pipes 1. Thus, the safe reception and removal of filtered water through the body of earthworks is ensured at all possible operational water levels in the WB.

Tubular drainage of a combined design can work effectively without major repairs for 20 years or more. Due to the fact that the geomat is a highly draining and sufficiently resistant material that can stay in the aquatic environment for 20 years or more. The use of a geomat provides not only water permeability and flexibility of the structure, but also contributes to the preservation of moisture in the body of the structure for a long time. This creates good conditions for the germination of grasses and shrubs on the lower slope of the earthen structure. Over time, the downstream slope will be completely overgrown with grass and shrubs, and in a few years it will turn into a continuous sod, sprouted with plant branches up and roots down and in breadth.

Thus, the tubular drainage of the proposed design does not interfere and will help the development of nature and be included in the ecosystem of the territory.

Tubular drainage of a combined design can be effectively used in the flat sections of rivers during the construction and reconstruction of earthen dams and embankment dams in areas where there is no sufficient amount of stone and gravel material. And also - in hard-to-reach places where the delivery of construction equipment is difficult.

A source of information

1. Hydraulic structures. Designer's Handbook. / Under the general editorship of Dr. tech. sciences, prof. V.P. Nedrigi. - M.: Stroyizdat, 1983, p. 172-173, p. 491.

2. Pat. 2412303 Russian Federation, IPC Е02В 11/00. Tubular drainage / Kurbanov C.O., Kurbanov K.S. V.M. Kokova. - No. 2008133950/03: Appl. 08/10/2010, Bull. No. 24. - 5 p.: ill.

Claims (1)

Tubular drainage of earthworks, containing inlet and outlet parts, consisting of perforated drainage pipes and flexible mattresses, characterized in that it is made of a combined design, where the receiving part is made of perforated drainage pipes with stiffening rings put on pipes at a distance from each other, around of the drainage pipes and between the stiffening rings, geomats are wrapped in layers, with a thickness equal to the height of the ribs of the stiffening rings, which, together with the perforated pipe, form the water intake part of the drainage, around which a protective sheath of gabion mesh is arranged, and the discharge part is made of flexible cylindrical mattresses, which are made of perforated pipes wrapped around with geomats and geogrid, and which are laid in dense rows from the water intake part of the drainage in the direction of the filtration flow towards the downstream of the structure.

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