Double anti-backflow retaining wall drainage pipe and use method thereof

Abstract

The invention discloses a double anti-backflow retaining wall drainage pipe and a method for using the same. The retaining wall drainage pipe comprises a perforated PVC pipe, a first wire mesh, a first anti-filter geotextile, an anti-backflow system I, a second wire mesh, a second anti-filter geotextile and an anti-backflow system II; the drainage hole of the perforated PVC pipe is provided with the first wire mesh, the first anti-filter geotextile and the anti-backflow system I in sequence from the outside to the inside, and the perforated PVC pipe is provided with the second anti-filter geotextile, the second wire mesh and the anti-backflow system II in sequence from the inside to the outside near the pipe mouth; the invention has a double anti-backflow system, which can not only ensure efficient drainage work, but also prevent external water sources from backflowing into the rock and soil layer behind the retaining wall, thereby causing the risk of excessive hydrostatic pressure of the retaining wall. The invention is convenient to construct and can be applied to drainage work in various projects such as foundation pit engineering and road slope engineering.

Description

Technical Field

[0001] The invention relates to a drainage device, in particular to a double anti-backflow retaining wall drainage pipe and a use method thereof, which can be used for drainage of slope engineering and prevention and control of slope seepage, backflow and collapse. Background Art

[0002] In recent years, with the continuous acceleration of my country's infrastructure construction process and the continuous improvement of urban infrastructure, retaining walls have been used more and more widely in municipal engineering. Retaining walls refer to structures that can prevent soil collapse or cut off the extension of soil slopes, support fill and materials and ensure their stability. They are widely used in various projects. The drainage system in the retaining wall structure can effectively drain the moisture of the soil behind the wall, prevent ground water from seeping in, prevent water accumulation behind the wall from forming hydrostatic pressure, reduce the frost heave pressure of backfill in cold areas, and eliminate the expansion pressure of clay soil fillers after water intrusion. Therefore, if the retaining wall does not have a good drainage system, it will not only have an adverse effect on its normal function, but also pose a serious threat to the safety of the entire building.

[0003] At present, the work of the traditional retaining wall drainage system is mainly arranged at two locations: the ground and the wall. The drainage work on the ground can be solved by digging drainage ditches, compacting the surrounding soil, and paving the corresponding road surface; and the drainage work behind the wall can be solved by laying a drainage pipe that runs through the wall. However, the above-mentioned traditional retaining wall drainage system has the following shortcomings: 1. In some areas of my country, there is heavy rainfall, which will cause the water level to rise sharply. However, from the current engineering situation, ordinary retaining wall drainage pipes are not equipped with anti-backflow systems, which makes it easy for external water sources to backflow into the soil behind the wall, causing the static water pressure behind the wall to be too large, and there is a safety hazard of retaining wall collapse. 2. Under the scouring effect of the water body, the mud flushed out from behind the wall will cause the wall drainage pipe to be blocked, resulting in a decrease in its drainage function, causing the static water pressure behind the wall to be too large, and there is a safety hazard of retaining wall collapse. 3. Under the action of water scouring, the mud behind the wall is washed out, the compactness of the soil behind the wall will be damaged, and the soil may be in danger of collapse, causing damage to the buildings above the soil and causing huge economic losses. 4. The mud and mortar flushed out from the pipeline will affect the traffic of vehicles and pedestrians on the road.

[0004] Therefore, in order to solve the design defects of traditional retaining wall drainage pipes, and to address the problems of drainage pipes being easily blocked and easily carrying out mud, there is an urgent need for a new type of retaining wall drainage pipe that is easy to construct and has low cost for drainage and sand filtering. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a double anti-backflow retaining wall drainage pipe and a use method thereof.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] On one hand, the present invention provides a double backflow prevention retaining wall drainage pipe, comprising a perforated PVC pipe, a first wire mesh, a first anti-filter geotextile, an anti-backflow prevention system I, a second wire mesh, a second anti-filter geotextile and an anti-backflow prevention system II; the perforated PVC pipe is composed of a front cone-shaped tip, a middle perforated section and a rear non-perforated section; the middle perforated section is provided with a plurality of drainage holes for connecting the internal drainage channel with the external rock and soil layer;

[0008] The drainage hole is provided with a first wire mesh, a first anti-filter geotextile and an anti-backflow system I in sequence from the outside to the inside. The first wire mesh is used to protect the first anti-filter geotextile and the anti-backflow system I during the installation and plugging process of the drainage pipe; the first anti-filter geotextile is used to filter groundwater in the rock and soil layer, dredge the groundwater but retain mud and sand; the anti-backflow system I is used to dredge the groundwater in the rock and soil layer filtered by the anti-filter geotextile, and prevent external water from backflowing into the rock and soil layer from the drainage channel;

[0009] The anti-backflow system I includes a bottom pad, a spring, a connecting rod, a water stopper and a top baffle from the inside to the outside; the bottom pad is a circular PVC plate fixed on the inner wall of the drainage hole, used to support the upper structure and drain the filtered groundwater; one end of the spring is fixed to the bottom pad, and the other end is fixedly connected to the water stopper through a connecting rod; the spring controls the displacement of the water stopper in the drainage hole by stretching or shortening after being stressed; the water stopper is a solid body with a wider inner side and a narrower outer side, the inner side is a V-shaped structure, the V-shaped structure is connected to the connecting rod, and the outer side is a cylindrical structure, which can fit tightly with the top baffle when external water source flows back into the rock and soil layer from the drainage channel in a closed state; the top baffle is a PVC plate with a hole in the middle;

[0010] The rear end non-porous section is provided with a second anti-filter geotextile, a second wire mesh and an anti-backflow system II in sequence from the inside to the outside; the anti-backflow system II is used to dredge the groundwater in the rock and soil layer filtered by the second anti-filter geotextile and prevent the external water source from backflowing into the rock and soil layer through the drainage channel; the second wire mesh is used to support and protect the second anti-filter geotextile;

[0011] The anti-backflow system II is composed of a float, a pad, an L-shaped rubber seal, a pressure plate and rivets; the pad is a cylindrical structure, fixed on the inner wall of the rear end non-porous section; the float is spherical, can move freely in the inner space of the pad and has a cavity with the inner wall of the pad, the cavity is used for groundwater to pass, the pad inlet end has a limit structure, used to prevent the float from moving out of the pad internal space, the pad outlet end is provided with an L-shaped rubber seal, which can fit tightly with the float during the anti-backflow work, so as to prevent the external water source from backflowing into the rock and soil layer; the pressure plate can tightly fix the L-shaped rubber seal on the pad under the action of the rivet;

[0012] The pad and the float have a certain cavity when performing drainage work to facilitate the drainage of the rock and soil layer; the float can move freely under the action of water, and when external water source flows back into the pipe mouth, the float can fit tightly with the L-shaped rubber sealing part under the action of water to prevent external water source from flowing back into the rock and soil layer.

[0013] Furthermore, the front cone-shaped tip and the middle section with holes are seamlessly connected to the front end of the pipe body, so that it is more convenient to push the drainage pipe into the rock and soil layer when laying the drainage pipe during the retaining wall construction; the rear end holeless section and the middle section with holes are made in one piece, so as to prevent water flow from eroding the internal structure of the retaining wall during future drainage.

[0014] Furthermore, a plurality of rows of drainage holes are provided along the axis of the middle perforated section, and two adjacent rows of drainage holes are arranged alternately. The diameter and distribution number of the drainage holes are determined by the local climate conditions and local soil conditions.

[0015] Furthermore, the spring should select a suitable stiffness coefficient to control the displacement of the water plug in the drain hole by extending or shortening itself after being subjected to force, so as to achieve the effect that the water plug and the top baffle are tightly fitted when external water flows back, and the water plug is opened when the water flow in the rock and soil layer is unblocked; the connecting rod is a crescent-shaped iron sheet that can tightly connect the spring and the water plug; the water plug is an integrally formed rubber water plug, and the narrower part on the outside should be slightly wider than the opening part of the top baffle; the bottom pad and the top baffle are fixedly connected to the inner wall of the drain hole to prevent internal components from slipping or being lost or damaged.

[0016] Furthermore, the float should be made of impermeable material to prevent external water from flowing back into the rock and soil layer; the pad has a curvature slightly smaller than the diameter of the float on the side close to the pipe mouth to prevent the float from slipping out of the hole during drainage and to ensure normal drainage; the L-shaped rubber sealing part should have a curvature that just fits the float at the contact surface with the float to prevent external water from flowing back into the rock and soil layer.

[0017] Furthermore, the perforated PVC tube needs to have certain strength and rigidity to ensure that it does not bend or deform during insertion and extraction.

[0018] Another aspect of the present invention provides a method for using a double anti-backflow retaining wall drain pipe, comprising the following steps:

[0019] (1) Prefabricate the double backflow prevention retaining wall drainage pipe in the factory, transport the prefabricated drainage pipe to the construction site, check whether the first wire mesh, the first anti-filter geotextile and the anti-backflow system I are consolidated in the drainage hole, and check whether the second anti-filter geotextile, the second wire mesh and the anti-backflow system II are consolidated in the drainage channel near the drainage pipe outlet;

[0020] (2) According to the design and construction drawings, after on-site investigation, determine the hole position of the double backflow prevention retaining wall drainage pipe, insert the double backflow prevention retaining wall drainage pipe into the water-rich area in the rock and soil layer by oblique drilling or oblique jacking at a certain speed, and confirm that the double backflow prevention retaining wall drainage pipe is not loose and does not slip after installation; the oblique drilling angle and speed are determined by laboratory tests or according to the design and construction drawings;

[0021] (3) After the installation of the double backflow prevention retaining wall drainage pipe is completed, maintenance is required. Use a wet towel slightly smaller than the opening of the double backflow prevention retaining wall drainage pipe to block the hole to prevent impurities from entering the drainage channel during the subsequent construction process, causing the drainage hole to be blocked, affecting the drainage effect during subsequent use;

[0022] (4) After the acceptance of the retaining wall project is completed, pull out the wet towel and put the double anti-backflow retaining wall drainage pipe into use;

[0023] (5) When precipitation occurs in the area or the water level in the water-rich area of ​​the rock and soil layer behind the retaining wall in the area rises, the double anti-backflow retaining wall drainage pipe starts to work, and the groundwater mixed with mud and water is filtered through the first anti-filter geotextile in the drainage hole, while the mud is left in the rock and soil layer. Due to the effect of water pressure, the spring contracts and the water retaining plug opens, allowing the filtered groundwater to flow out to the outside through the drainage channel, thereby achieving the effect of reducing the hydrostatic pressure behind the rock and soil layer;

[0024] When the external water level rises sharply and submerges the retaining wall drainage pipe, under the action of water pressure, the anti-backflow system II starts to work, and the float fits tightly with the L-shaped rubber seal to achieve the effect of preventing the first level of external water source from backflowing into the rock and soil layer behind the retaining wall. If the anti-backflow system II fails, then under the action of water pressure, the spring in the anti-backflow system I extends and the water stopper closes to achieve the effect of preventing the second level of external water source from backflowing into the rock and soil layer behind the retaining wall.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention can select different forms of drainage pipes according to different climatic conditions in different regions. Conventional retaining wall drainage pipes are installed in areas with less precipitation, and double anti-backflow retaining wall drainage pipes are installed in areas with more precipitation. This realizes the adaptation of retaining wall drainage devices to local conditions and has broad engineering application prospects.

[0027] 2. The present invention has a double backflow prevention system, which can perform double backflow prevention on external water sources through the backflow prevention system I and the backflow prevention system II, which can not only ensure efficient drainage, but also prevent the external water source from backflowing into the rock and soil layer behind the retaining wall, thereby preventing the risk of excessive hydrostatic pressure of the retaining wall.

[0028] 3. The present invention adopts a PVC plastic pipe body, and the front section of the perforated plastic pipe adopts a cone-shaped tip, which can be easily tapped into the rock and soil layer behind the retaining wall, thereby realizing the rapid and safe construction of the double anti-backflow retaining wall drainage pipe, saving the construction cost and construction period, and having little impact on the surrounding environment of the double anti-backflow retaining wall drainage pipe construction site; the retaining wall drainage pipe of the present invention is easy to install and construct, and has a significant effect in preventing and controlling the problem that the retaining wall cannot be drained normally due to blockage by mud and sand, and has broad engineering application prospects.

[0029] 4. The present invention separates the water guide part from the drainage part. The drainage part is directly connected to the external rock and soil layer and is provided with openings, so that the drainage part can be in full contact with the rock and soil layer to achieve efficient drainage; the water guide part is directly embedded in the retaining wall part and the pipe body has no openings, so that the retaining wall is prevented from being corroded by rainwater while guiding water, achieving efficient drainage while also preventing the problem of water seepage in the retaining wall.

[0030] 5. The drainage holes of the present invention are evenly distributed around the perforated PVC pipe body in both directions. On the one hand, it is beneficial to reduce the adverse effects of the openings on the perforated PVC pipe. On the other hand, it can drain water more efficiently and achieve a significant drainage effect. Each drainage hole is provided with an anti-filter geotextile, which can effectively filter soil and drain water.

[0031] 6. The present invention adopts common materials and shapes, which makes it easy to realize mass production of retaining wall drainage pipes, and is convenient to construct and can be applied to drainage work in various projects such as foundation pit projects and road slope projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The appearance diagram of the double anti-backflow retaining wall drainage pipe provided by the embodiment of the present invention;

[0033] Figure 2 A side view of a double backflow prevention retaining wall drain pipe provided by an embodiment of the present invention;

[0034] Figure 3A cross-sectional view of the double anti-backflow retaining wall drainage pipe provided by an embodiment of the present invention when backflow does not occur;

[0035] Figure 4 A cross-sectional view of a double anti-backflow retaining wall drainage pipe provided by an embodiment of the present invention when backflow occurs;

[0036] Figure 5 This is the enlarged view of point A;

[0037] Figure 6 This is an enlarged view of point B;

[0038] Figure 7 A partial enlarged view of the drainage hole of the double anti-backflow retaining wall drainage pipe provided by an embodiment of the present invention;

[0039] Figure 8 A partial enlarged view of a drainage hole of a conventional retaining wall drainage pipe provided in an embodiment of the present invention;

[0040] In the figure, there are perforated PVC pipe 1, first wire mesh 2, first anti-filter geotextile 3, third wire mesh 4, drainage channel 5, anti-backflow system I 6, bottom pad 6-1, spring 6-2, connecting rod 6-3, water stopper 6-4, top baffle 6-5, second wire mesh 7, anti-backflow system II 8, float 8-1, pad 8-2, L-shaped rubber seal 8-3, pressure plate 8-4, rivet 8-5, and second anti-filter geotextile 9. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0042] like Figure 1-7 As shown, the present embodiment provides a double anti-backflow retaining wall drainage pipe, comprising a perforated PVC pipe 1, a first wire mesh 2, a first anti-filter geotextile 3, an anti-backflow system I6, a second wire mesh 7, a second anti-filter geotextile 9 and an anti-backflow system II8; the perforated PVC pipe 1 is composed of a front cone-shaped tip 1-1, a middle perforated section and a rear end non-perforated section 1-2; the middle perforated section is provided with a plurality of drainage holes 1-3 for connecting the internal drainage channel 5 with the external rock and soil layer.

[0043] The drainage holes 1-3 are provided with a first wire mesh 2, a first anti-filter geotextile 3 and an anti-backflow system I6 in sequence from the outside to the inside. The first wire mesh 2 is used to protect the first anti-filter geotextile 3 and the anti-backflow system I6 during the installation and plugging process of the drainage pipe; the first anti-filter geotextile 3 is used to filter the groundwater in the rock and soil layer, dredge the groundwater but retain the mud and sand; the anti-backflow system I6 is used to dredge the groundwater in the rock and soil layer after being filtered by the anti-filter geotextile 3, and prevent external water from backflowing into the rock and soil layer from the drainage channel 5.

[0044] like Figure 7 As shown, the anti-backflow system Ⅰ6 includes a bottom pad 6-1, a spring 6-2, a connecting rod 6-3, a water stopper 6-4 and a top baffle 6-5 from the inside to the outside; the bottom pad 6-1 is a circular PVC plate fixed on the inner wall of the drainage hole 1-3, which is used to support the upper structure and drain the filtered groundwater; one end of the spring 6-2 is fixed on the bottom pad 6-1, and the other end is fixedly connected to the water stopper 6-4 through the connecting rod 6-3; the spring 6-2 controls the displacement of the water retaining plug 6-4 in the drainage hole 1-3 by stretching or shortening itself after being subjected to force; the water retaining plug 6-4 is a solid body which is wider on the inside and narrower on the outside, the inside is a V-shaped structure which is connected to the connecting rod 6-3, and the outside is a cylindrical structure which can fit tightly with the top baffle 6-5 when external water flows back into the rock and soil layer from the drainage channel 5 in a closed state; the top baffle 6-5 is a PVC board with a hole in the middle.

[0045] The rear end non-porous section 1-2 is provided with a second anti-filter geotextile 9, a second wire mesh 7 and an anti-backflow system II8 from the inside to the outside; the anti-backflow system II8 is used to dredge the groundwater in the rock and soil layer after being filtered by the second anti-filter geotextile 9, and prevent external water from backflowing into the rock and soil layer through the drainage channel 5; the second wire mesh 7 is used to support and protect the second anti-filter geotextile 9.

[0046] like Figure 5 , 6 As shown, the anti-backflow system II8 is composed of a float 8-1, a pad 8-2, an L-shaped rubber seal 8-3, a pressure plate 8-4 and a rivet 8-5; the pad 8-2 is a cylindrical structure, fixed on the inner wall of the rear end holeless section 1-2; the float 8-1 is spherical, can move freely in the internal space of the pad 8-2 and has a cavity with the inner wall of the pad 8-2, the cavity is used for groundwater to pass, the pad 8-2 inlet end has a limiting structure, used to prevent the float 8-1 from moving out of the internal space of the pad 8-2, the pad 8-2 outlet end is provided with an L-shaped rubber seal 8-3, which is used to fit tightly with the float 8-1 when performing anti-backflow work, so as to achieve the effect of preventing external water from backflowing into the rock and soil layer; the pressure plate 8-4 can tightly fix the L-shaped rubber seal 8-3 on the pad 8-2 under the action of the rivet 8-5.

[0047] The pad 8-2 and the float 8-1 have a certain cavity when performing drainage work to facilitate the drainage of the rock and soil layer; the float 8-1 can move freely under the action of water. When external water source flows back into the pipe mouth, the float 8-1 can fit tightly with the L-shaped rubber sealing part 8-3 under the action of water to prevent external water source from flowing back into the rock and soil layer.

[0048] Specifically, the front cone-shaped tip 1-1 and the middle section with holes are seamlessly connected to the front end of the pipe body, so as to facilitate the penetration into the rock and soil layer when laying the drainage pipe during the construction of the retaining wall; the rear end holeless section 1-2 is made integrally with the middle section with holes, so as to prevent water flow from eroding the internal structure of the retaining wall during future drainage.

[0049] Specifically, a plurality of rows of drainage holes 1-3 are provided along the axis of the middle perforated section, and two adjacent rows of drainage holes 1-3 are arranged alternately. The diameter and distribution number of the drainage holes 1-3 are determined by the local climate conditions and local soil conditions.

[0050] Specifically, the spring 6-2 should select a suitable stiffness coefficient to control the displacement of the water stopper 6-4 in the drainage hole 1-3 by its own extension or shortening after being subjected to force, so as to achieve the effect that the water stopper 6-4 and the top baffle 6-5 fit tightly when external water flows back, and the water stopper 6-4 is opened when the water flow in the rock and soil layer is unblocked; the connecting rod 6-3 is a crescent-shaped iron sheet that can tightly connect the spring 6-2 and the water stopper 6-4; the water stopper 6-4 is an integrally formed rubber water stopper, and the narrower part on the outside should be slightly wider than the opening part of the top baffle 6-5; the bottom pad 6-1 and the top baffle 6-5 are both fixedly connected to the inner wall of the drainage hole 1-3 to prevent internal components from slipping or being lost or damaged.

[0051] Specifically, the float 8-1 should be made of impermeable material to prevent external water from flowing back into the rock and soil layer; the pad 8-2 has a curvature slightly smaller than the diameter of the float 8-1 on the side close to the pipe mouth to prevent the float 8-1 from slipping out of the hole during drainage and to ensure normal drainage; the L-shaped rubber sealing part 8-3 should have a curvature that just fits the float 8-1 at the contact surface with the float 8-1 to prevent external water from flowing back into the rock and soil layer.

[0052] In this embodiment, for the slope protection project, according to the difference in rainfall in the climatic conditions of different regions, two corresponding processing methods can be used, as described below:

[0053] Case 1: When it is necessary to install retaining wall drain pipes in areas with low rainfall, conventional retaining wall drain pipes are used, such as Figure 8As shown, the conventional retaining wall drainage pipe includes a perforated PVC pipe 1, a first wire mesh 2, a first anti-filter geotextile 3 and a third wire mesh 4; the perforated PVC pipe 1 is composed of a front cone-shaped tip 1-1, a middle perforated section and a rear end non-perforated section 1-2; the middle perforated section is provided with a plurality of drainage holes 1-3 for connecting the internal drainage channel 5 with the external rock and soil layer; the drainage holes 1-3 are provided with a first wire mesh 2, a first anti-filter geotextile 3 and a third wire mesh 4 in sequence from the outside to the inside, the first anti-filter geotextile 3 is used to filter groundwater in the rock and soil layer, dredge the groundwater but retain mud and sand, and the first wire mesh 2 and the third wire mesh 4 are used to protect and support the first anti-filter geotextile 3 during the installation and insertion of the drainage pipe.

[0054] When precipitation occurs in the area or the water level in the water-rich area of ​​the rock and soil layer behind the retaining wall in the area rises, the conventional retaining wall drainage pipe starts to work, and the water mixed with mud and water is filtered through the first anti-filter geotextile 3 in the drainage holes 1-3, while the mud is left in the rock and soil layer, and the filtered water is discharged through the drainage channel 5.

[0055] Case 2: Installing the double anti-backflow retaining wall drainage pipe of the present invention in areas with heavy rainfall to prevent backflow caused by rising water levels, specifically including the following steps:

[0056] (1) Prefabricate the double anti-backflow retaining wall drainage pipe in the factory, transport the prefabricated drainage pipe to the construction site, check whether the first wire mesh 2, the first anti-filter geotextile 3 and the anti-backflow system I 6 are fixed in the drainage holes 1-3, and check whether the second anti-filter geotextile 9, the second wire mesh 7 and the anti-backflow system II 8 are fixed in the drainage channel 5 near the drainage pipe outlet;

[0057] (2) According to the design and construction drawings, after on-site investigation, determine the hole position of the double backflow prevention retaining wall drainage pipe, insert the double backflow prevention retaining wall drainage pipe into the water-rich area in the rock and soil layer by oblique drilling or oblique pushing at a certain speed, and confirm that the double backflow prevention retaining wall drainage pipe is not loose and does not slip after installation;

[0058] (3) After the installation of the double backflow prevention retaining wall drainage pipe is completed, maintenance is required. A wet towel slightly smaller than the opening of the double backflow prevention retaining wall drainage pipe is used to block the hole to prevent impurities from entering the drainage channel 5 during the subsequent construction process, causing the drainage holes 1-3 to be blocked, affecting the drainage effect during subsequent use;

[0059] (4) After the acceptance of the retaining wall project is completed, pull out the wet towel and put the double anti-backflow retaining wall drainage pipe into use;

[0060] (5) When precipitation occurs in the area or the water level in the water-rich area of ​​the rock and soil layer behind the retaining wall in the area rises, the double anti-backflow retaining wall drainage pipe starts to work, and the groundwater mixed with mud and water is filtered through the first anti-filter geotextile 3 in the drainage hole 1-3, while the mud is left in the rock and soil layer. Due to the effect of water pressure, the spring 6-2 contracts, the water retaining plug 6-4 opens, and the filtered groundwater flows out to the outside through the drainage channel 5, thereby achieving the effect of reducing the hydrostatic pressure behind the rock and soil layer;

[0061] When the external water level rises sharply and submerges the retaining wall drainage pipe, under the action of water pressure, the anti-backflow system II8 starts to work, and the float 8-1 fits tightly with the L-shaped rubber seal 8-3 to achieve the effect of preventing the first level of external water source from backflowing into the rock and soil layer behind the retaining wall. If the anti-backflow system II8 fails, then under the action of water pressure, the spring 6-2 in the anti-backflow system I6 extends and the water stopper 6-4 closes to achieve the effect of preventing the second level of external water source from backflowing into the rock and soil layer behind the retaining wall.

[0062] The above description is only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanation here, those skilled in the art can associate other specific implementations of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A double anti-backflow retaining wall drainage pipe, characterized in that: It comprises a perforated PVC pipe (1), a first wire mesh (2), a first anti-filter geotextile (3), an anti-backflow system I (6), a second wire mesh (7), a second anti-filter geotextile (9) and an anti-backflow system II (8); the perforated PVC pipe (1) comprises a front cone-shaped tip (1-1), a middle perforated section and a rear non-perforated section (1-2); the middle perforated section is provided with a plurality of drainage holes (1-3) for connecting an internal drainage channel (5) with an external rock layer; The drainage holes (1-3) are provided with a first wire mesh (2), a first anti-filter geotextile (3) and an anti-backflow system I (6) in sequence from the outside to the inside; the anti-backflow system I (6) is used to clear the groundwater in the rock and soil layer after being filtered by the first anti-filter geotextile (3) and prevent external water from backflowing into the rock and soil layer from the drainage channel (5); The anti-backflow system I (6) comprises, from the inside to the outside, a bottom pad (6-1), a spring (6-2), a connecting rod (6-3), a water stopper (6-4) and a top baffle (6-5); the bottom pad (6-1) is a circular PVC plate fixed on the inner wall of the drainage hole (1-3) and used to support the upper structure and drain the filtered groundwater; one end of the spring (6-2) is fixed on the bottom pad (6-1), and the other end is connected to the bottom pad (6-1) through the connecting rod (6-3). The water retaining plug (6-4) is fixedly connected; the spring (6-2) controls the displacement of the water retaining plug (6-4) in the drainage hole (1-3) by extending or shortening itself after being stressed; the water retaining plug (6-4) is a solid body with a wider inner side and a narrower outer side, the inner side is a V-shaped structure connected to the connecting rod (6-3), and the outer side is a cylindrical structure that can be tightly fitted with the top baffle (6-5) in a closed state; the top baffle (6-5) is a PVC plate with a hole in the middle; The rear end non-porous section (1-2) is provided with a second anti-filter geotextile (9), a second wire mesh (7) and an anti-backflow system II (8) in sequence from the inside to the outside; the anti-backflow system II (8) is used to dredge the groundwater in the rock and soil layer after being filtered by the second anti-filter geotextile (9) and prevent external water from backflowing into the rock and soil layer through the drainage channel (5); The anti-backflow system II (8) comprises a float (8-1), a pad (8-2), an L-shaped rubber sealing portion (8-3) and a pressure plate (8-4); the pad (8-2) is a cylindrical structure fixed on the inner wall of the rear end non-porous section (1-2); the float (8-1) is spherical and can move freely in the inner space of the pad (8-2) and has a cavity with the inner wall of the pad (8-2), the cavity is used for groundwater to pass through, and the pad (8-2) is a cylindrical structure fixed on the inner wall of the rear end non-porous section (1-2); the float (8-1) is spherical and can move freely in the inner space of the pad (8-2) and has a cavity with the inner wall of the pad (8-2), and the cavity is used for groundwater to pass through. ) an inlet end is provided with a limiting structure for preventing the float (8-1) from sliding out of the internal space of the pad (8-2); an L-shaped rubber sealing portion (8-3) is provided at the outlet end of the pad (8-2) for tightly fitting with the float (8-1) during backflow prevention work to prevent external water from backflowing into the rock and soil layer; the pressure plate (8-4) tightly fixes the L-shaped rubber sealing portion (8-3) to the pad (8-2) via rivets (8-5); The front cone-shaped tip (1-1) and the middle section with holes are seamlessly connected to the front end of the pipe body, so that the drainage pipe can be more conveniently pushed into the rock layer when laying the drainage pipe during the construction of the retaining wall; the rear end section without holes (1-2) and the middle section with holes are made in one piece, so as to prevent the water flow from eroding the internal structure of the retaining wall during the drainage process; A plurality of rows of drainage holes (1-3) are provided along the axis of the middle perforated section, and two adjacent rows of drainage holes (1-3) are arranged in a staggered manner. The diameter and distribution number of the drainage holes (1-3) are determined by local climate conditions and local soil conditions.

2. A double backflow prevention retaining wall drainage pipe according to claim 1, characterized in that: The spring (6-2) controls the displacement of the water retaining plug (6-4) in the drainage hole (1-3) by extending or shortening itself after being subjected to force, so as to achieve the effect that the water retaining plug (6-4) and the top baffle (6-5) are tightly fitted when external water flows back, and the water retaining plug (6-4) is opened when the water flow in the rock and soil layer is unblocked; the connecting rod (6-3) is a crescent-shaped iron sheet that can tightly connect the spring (6-2) and the water retaining plug (6-4); the water retaining plug (6-4) is an integrally formed rubber water retaining plug, and the narrower outer portion of the water retaining plug should be slightly wider than the opening portion of the top baffle (6-5).

3. A double anti-backflow retaining wall drainage pipe according to claim 1, characterized in that: The float (8-1) is made of impermeable material; the pad (8-2) has an arc slightly smaller than the diameter of the float (8-1) on the side close to the pipe mouth, so as to prevent the float (8-1) from sliding out of the pipe mouth during drainage work and ensure normal drainage work; the L-shaped rubber sealing part (8-3) should have an arc that just fits the float (8-1) at the contact surface with the float (8-1), so as to prevent external water from flowing back into the rock and soil layer.

4. A double backflow prevention retaining wall drainage pipe according to claim 1, characterized in that: The perforated PVC tube (1) has certain strength and rigidity to ensure that it will not bend or deform during insertion and extraction.

5. A method for using the double anti-backflow retaining wall drainage pipe according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: (1) Prefabricate the double anti-backflow retaining wall drainage pipe in the factory, transport the prefabricated retaining wall drainage pipe to the construction site, check whether the first wire mesh (2), the first anti-filter geotextile (3) and the anti-backflow system I (6) are fixed in the drainage hole (1-3), and check whether the second anti-filter geotextile (9), the second wire mesh (7) and the anti-backflow system II (8) are fixed in the drainage channel (5) near the drainage pipe outlet; (2) According to the design and construction drawings, after on-site investigation, determine the hole position of the double backflow prevention retaining wall drainage pipe, insert the retaining wall drainage pipe into the water-rich area in the rock and soil layer by oblique drilling or oblique pushing at a certain speed, and confirm that the retaining wall drainage pipe is not loose and does not slip after installation; (3) After the installation of the double backflow prevention retaining wall drainage pipe is completed, maintenance is required, and the hole is blocked with a wet towel to prevent impurities from entering the drainage channel (5) during the subsequent construction process, causing the drainage holes (1-3) to be blocked, affecting the drainage effect during subsequent use; (4) After the acceptance of the retaining wall project is completed, pull out the wet towel and put the double anti-backflow retaining wall drainage pipe into use; (5) When precipitation occurs in the area or the water level in the water-rich area of ​​the rock and soil layer behind the retaining wall in the area rises, the double anti-backflow retaining wall drainage pipe starts to work, and the groundwater mixed with mud and water is filtered through the first anti-filter geotextile (3) in the drainage hole (1-3), while the mud is left in the rock and soil layer. Due to the effect of water pressure, the spring (6-2) contracts, the water retaining plug (6-4) opens, and the filtered groundwater is discharged through the drainage channel (5), thereby achieving the effect of reducing the hydrostatic pressure behind the rock and soil layer; When the external water level rises sharply and submerges the retaining wall drainage pipe, the anti-backflow system II (8) starts to work under the action of water pressure, and the float (8-1) and the L-shaped rubber seal (8-3) fit tightly together, so as to achieve the effect of preventing the first level of external water from backflowing into the rock and soil layer behind the retaining wall. If the anti-backflow system II (8) fails, the spring (6-2) in the anti-backflow system I (6) will extend under the action of water pressure, and the water stopper (6-4) will close, so as to achieve the effect of preventing the second level of external water from backflowing into the rock and soil layer behind the retaining wall.

6. The method according to claim 5, characterized in that: In the step (2), the angle of the bevel and the speed are determined by testing in the laboratory or according to the design and construction drawings.

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