A method and structure for draining groundwater from the bottom and surrounding areas of a basement

Abstract

The present invention discloses a method and structure for draining groundwater from the basement bottom and surrounding areas. The method comprises installing vertically and horizontally intersecting drainage ditches around the basement and at the basement bottom, and providing water collection wells at the intersections to temporarily collect water from the drainage ditches and then direct it to precipitation wells located at the four corners of the basement's exterior walls. Submersible pumps within the precipitation wells pump the water from the precipitation wells to outdoor ground-based water storage and sedimentation tanks, where the settled water is reused as construction water. The present invention effectively solves the problem of drainage during foundation pit construction, speeds up construction, converts construction wastewater into reclaimed water for comprehensive water resource utilization, and achieves water conservation and construction cost reduction. It also reduces groundwater pressure, avoids the risk of leakage from the basement floor and exterior walls, and ensures project quality.

Description

Technical Field

[0001] The invention relates to a method and structure for draining groundwater at the bottom and around a basement, and belongs to the technical field of prefabricated component construction of bridge engineering. Background Art

[0002] With the rapid expansion of modern buildings, construction land is gradually becoming scarce. The topography of construction project sites is often complex and diverse, with deep foundation pits, large foundation pit areas, and a large amount of groundwater and rainwater in the foundation pits. This makes it difficult to drain groundwater during foundation pit construction, and the construction progress is slow. After the building is put into use, a large number of water leakage points will appear on the floor and exterior walls, and the subsequent anti-seepage and plugging of leaks will be quite difficult. The use of existing technologies for drainage and precipitation cannot ensure the orderly development of the construction surface during the construction process. When the groundwater level rises during the flood season, the groundwater exerts pressure on the floor, which will damage the basement foundation structure and cause leakage of the floor and exterior walls. In addition, the use of existing technologies to treat the water in the foundation pit, especially the deep foundation pit, and then discharge it into the municipal sewage network is costly, difficult to construct, and not conducive to the utilization of water resources. Therefore, the existing technology still has shortcomings and needs to be improved. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and structure for draining groundwater at the bottom and around the basement, so as to solve technical problems such as difficulty in draining groundwater during foundation pit construction, leakage caused by excessive water pressure on the bottom plate and basement outer wall, and impact on the quality of the foundation structure, thereby overcoming the shortcomings of the existing technology.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a method for draining groundwater at the bottom and around a basement. The method comprises setting up vertically and horizontally intersecting drainage ditches around and at the bottom of the basement, and setting up water collection wells at the vertical and horizontal intersections to temporarily collect water from the drainage ditches and then lead the water to precipitation wells located at the four corners of the basement outer wall. The water in the precipitation wells is pumped to a water storage sedimentation tank on the outdoor ground by a submersible pump in the precipitation wells, and the water after sedimentation is reused as construction water.

[0006] In the above-mentioned method of draining groundwater from the bottom and surrounding areas of the basement, the construction steps of the above method are as follows:

[0007] a. When excavating the basement foundation pit, the foundation pit should be excavated to a depth of 200mm below the bottom surface of the basement floor;

[0008] b. Continue digging at the four corners of the basement's outer wall to a depth of 3m below the basement floor elevation, and then use reinforced concrete to cast a drainage well in the deep pit;

[0009] c. Tamp the bottom of the foundation pit to form a rammed earth layer; pour a 100mm thick concrete cushion layer on top of the rammed earth layer;

[0010] d. Use gray bricks to build water collection wells on the concrete cushion layer. The water collection wells are arranged in rows and columns on the concrete cushion layer outside the basement floor and basement exterior wall to be poured;

[0011] e. Lay the lower geotextile on the concrete cushion layer, and lay the filter layer on the lower geotextile;

[0012] f. Install drainage trenches on the top surface of the filter layer, connecting all water collection wells and precipitation wells at the four corners of the basement exterior wall through the drainage trenches to form a drainage grid;

[0013] g. Lay the upper geotextile on the top surface of the filter layer and drainage ditch; backfill the top surface of the upper geotextile with the covering soil layer to the bottom surface level of the basement floor and tamp it;

[0014] h. Complete the concrete pouring construction of the basement floor and basement exterior wall on the top surface of the covering soil layer; backfill the soil outside the basement exterior wall to the outdoor ground level and tamp it;

[0015] i. Construct a water storage and sedimentation tank on one side of the wellhead of the precipitation well; and install a float valve and a submersible pump at the bottom of the precipitation well. The submersible pump pumps the water in the precipitation well to the water storage and sedimentation tank through the pumping pipe for reuse after sedimentation.

[0016] In the above-mentioned method of diverting and draining groundwater at the bottom and around the basement, the drainage ditch is paved with a finished ∩-shaped trough; the lower opening of the ∩-shaped trough is 400mm wide and 500mm high; a semicircular hole with a radius of 200mm is provided in the middle of the bottom of the two side walls of the ∩-shaped trough as a water inlet hole.

[0017] In the above-mentioned method of draining groundwater from the bottom of and around the basement, when laying the drainage ditch, the connections between each section of the ∩-shaped trough and between it and the collection well or precipitation well are connected with M10.0 cement mortar; the drainage ditch should be laid with the middle high and the four corners low to form a drainage slope of 0.5%.

[0018] In the above-mentioned method of draining groundwater at the bottom and around the basement, the filtration layer is composed of a pebble layer and a crushed stone layer; when laying the crushed stone layer, the crushed stone layer forms an oblique triangular accumulation at the bottom of both sides of the drainage ditch; the top height of the triangular accumulation should cover the water inlet holes on both sides of the drainage ditch.

[0019] In the above-mentioned method of draining groundwater at the bottom and around the basement, when laying the upper layer of geotextile on the gravel layer and the top surface of the drainage ditch, the geotextile should be laid close to the top surface of the drainage ditch and the triangular pile.

[0020] In the above-mentioned method of groundwater drainage at the bottom and around the basement, the pouring of the precipitation well is carried out in sections. During pouring, a steel ladder is embedded in the well wall on one side of the precipitation well. The first pouring height is higher than the elevation of the basement floor to be poured. After the construction of the rammed earth layer, concrete cushion layer, water collection well, lower geotextile, filter layer and upper geotextile is completed, the upper section of the precipitation well is poured to the ground elevation.

[0021] The present invention is a basement bottom and surrounding groundwater drainage structure constructed according to the above-mentioned basement bottom and surrounding groundwater drainage method, including precipitation wells located at the four corners of the basement and a group of collection wells located below the basement floor and outside the basement outer wall; the group of collection wells and the precipitation wells at the four corners of the basement are connected via drainage trenches; a submersible pump and a float valve are provided in the precipitation well, and the submersible pump is located on the precipitation well floor; the submersible pump is connected to a water storage sedimentation tank on the outdoor ground via a pumping pipe.

[0022] In the aforementioned groundwater drainage structure at the bottom and around the basement, the drainage ditch is a connecting piece composed of a group of ∩-shaped grooves; the lower mouth of the ∩-shaped groove is 400mm wide and 500mm high; a water inlet hole with a radius of 200mm is provided in the middle of the bottom of the two side walls of the ∩-shaped groove.

[0023] In the above-mentioned groundwater drainage structure at the bottom and around the basement, an upper layer of geotextile is arranged in sequence from bottom to top between the top of the drainage ditch and the bottom surface of the basement floor, and a covering soil layer is provided on the top surface of the upper geotextile; a crushed stone layer, a pebble layer, a concrete cushion layer and a rammed soil layer are arranged in sequence from top to bottom below the drainage ditch; among them, the crushed stone layer is provided with a triangular accumulation on the outside of the drainage ditch to cover the water inlet hole of the drainage ditch.

[0024] Due to the adoption of the above technical solution, compared with the existing technology, this invention effectively utilizes the concept of "combining drainage and comprehensive utilization" by draining groundwater and rainwater from under the floor and around the basement exterior walls into precipitation wells, and then pumping the water out through the precipitation wells to outdoor water storage and sedimentation tanks. This solves the drainage problem during foundation pit construction, speeds up construction, converts construction wastewater into reclaimed water for comprehensive water resource utilization, saves water and reduces construction costs, reduces groundwater pressure, avoids the risk of leakage in the basement floor and basement exterior walls, and ensures project quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention;

[0026] Figure 2 It is the front view of the cross section of the concealed drainage blind ditch;

[0027] Figure 3 It is a structural diagram of the ∩-shaped groove.

[0028] The markings in the figure are as follows: 1-drainage ditch, 2-water collection well, 3-precipitation well, 4-water storage sedimentation tank, 5-basement floor, 6-basement exterior wall, 7-outdoor ground, 8-concrete cushion, 9-pebble layer, 10-lower geotextile, 11-rammed soil layer, 12-covering soil layer, 13-submersible pump, 14-float valve, 15-pumping pipe, 16-steel ladder, 17-precipitation well cover, 18-well wall, 19-precipitation well floor, 20-water inlet, 21-upper geotextile, 22-gravel layer, 23-triangular accumulation. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] The present invention provides a method for draining groundwater from the bottom and surrounding areas of a basement. Figures 1 to 3 As shown, the method is to set up vertical and horizontal intersecting drainage ditches 1 around and at the bottom of the basement, and set up collection wells 2 at the vertical and horizontal intersections to temporarily collect water from the drainage ditches 1 and then lead it to precipitation wells 3 located at the four corners of the basement outer wall 6. The water in the precipitation well 3 is pumped to the water storage sedimentation tank 4 on the outdoor ground 7 by the submersible pump 13 in the precipitation well 3, and the water after sedimentation is reused as construction water.

[0031] The construction steps for the above-mentioned method of draining groundwater from the bottom and surrounding areas of the basement are as follows:

[0032] a. When excavating the basement foundation pit, the foundation pit should be excavated to a depth of 200mm below the bottom surface of the basement floor 5;

[0033] b. Continue digging at the four corners of the basement exterior wall 6 to a depth of 3m below the basement floor 5 elevation, and then use reinforced concrete to cast a drainage well 3 in the deep pit;

[0034] c. Tamp the bottom of the foundation pit to form a rammed earth layer 11; pour a 100 mm thick concrete cushion layer 8 on top of the rammed earth layer 11;

[0035] d. Use gray bricks to build water collection wells 2 on the concrete cushion 8. The water collection wells 2 are arranged in rows and columns on the concrete cushion 8 outside the basement floor 5 and the basement outer wall 6 to be poured;

[0036] e. Laying a lower layer of geotextile 10 on the concrete cushion 8, and laying an anti-filtration layer on the lower layer of geotextile 10;

[0037] f. Install a drainage ditch 1 on the top surface of the filter layer, and connect all the water collection wells 2 and the precipitation wells 3 located at the four corners of the basement outer wall 6 through the drainage ditch 1 to form a drainage grid;

[0038] g. Lay an upper geotextile 21 on the top surface of the filter layer and the drainage ditch 1; backfill the top surface of the upper geotextile 21 with a covering soil layer 12 to the bottom surface level of the basement floor 5 and compact it;

[0039] h. Complete the concrete pouring construction of the basement floor 5 and the basement exterior wall 6 on the top surface of the covering soil layer 12; backfill the soil outside the basement exterior wall 6 to the outdoor ground level 7 and tamp it;

[0040] i. Build a water storage sedimentation tank 4 on one side of the wellhead of the precipitation well 3; and install a float valve 14 and a submersible pump 13 at the bottom of the precipitation well 3. The submersible pump 13 pumps the water in the precipitation well 3 to the water storage sedimentation tank 4 through a pumping pipe 15 for reuse after sedimentation.

[0041] In the above method, the drainage ditch 1 is laid using a pre-made ∩-shaped trough. The ∩-shaped trough has a bottom width of 400mm and a height of 500mm. A semicircular hole with a radius of 200mm is provided in the center of the bottom of each side wall of the ∩-shaped trough, serving as the water inlet 20. During the laying of the drainage ditch 1, each section of the ∩-shaped trough and the connections to the water collection well 2 or precipitation well 3 are connected using M10.0 cement mortar. The drainage ditch 1 should be laid with the center higher and the four corners lower, forming a drainage slope of 0.5%. The filter layer consists of a pebble layer 9 and a crushed stone layer 22. During the laying of the crushed stone layer 22, the crushed stone layer 22 forms an oblique triangular pile 23 at the bottom of each side of the drainage ditch 1. The top of the triangular pile 23 should be high enough to cover the water inlet 20 on both sides of the drainage ditch 1. When laying the upper geotextile 21 on the gravel layer 22 and the top surface of the drainage ditch 1, the geotextile should be laid closely to the top surface of the drainage ditch 1 and the triangular pile 23. The precipitation well 3 is cast in sections, with a steel ladder 16 embedded in the well wall 18 on one side of the precipitation well 3. The initial casting height is higher than the elevation of the basement floor 5 to be cast. After the construction of the rammed earth layer 11, concrete cushion layer 8, water collection well 2, lower geotextile 10, filter layer, and upper geotextile 21 is completed, the upper section of the precipitation well 3 is cast to the ground level.

[0042] The present invention is a basement bottom and surrounding groundwater drainage structure constructed according to the above method, such as Figures 1 to 3As shown, the structure includes drainage wells 3 located at the four corners of the basement and a set of water collection wells 2 located below the basement floor 5 and outside the basement exterior wall 6. The water collection wells 2 are connected to the four corner drainage wells 3 via a drainage culvert 1. A submersible pump 13 and a float valve 14 are installed within the drainage wells 3. The submersible pump 13 is located on the drainage well floor 19. The submersible pump 13 is connected to the water storage and sedimentation tank 4 on the outdoor ground 7 via a pumping pipe 15. The drainage culvert 1 is a connecting piece consisting of a set of ∩-shaped grooves. The lower opening of the ∩-shaped grooves is 400 mm wide and 500 mm high. Water inlet holes 20 with a radius of 200 mm are located in the center of the bottom of the two side walls of the ∩-shaped grooves. An upper layer of geotextile 21 is arranged between the top of the drainage ditch 1 and the bottom surface of the basement floor 5 from bottom to top, and a covering soil layer 12 is provided on the top surface of the upper geotextile 21; a crushed stone layer 22, a pebble layer 9, a concrete cushion layer 8 and a rammed soil layer 11 are arranged below the drainage ditch 1 from top to bottom; among them, the crushed stone layer 22 is provided with a triangular pile 23 on the outside of the drainage ditch 1 to cover the water inlet 20 of the drainage ditch 1. Example

[0043] The structure of this example is as follows Figures 1 to 3As shown, it includes: drainage culvert 1, water collection well 2, precipitation well 3, water storage sedimentation tank 4. The foundation pit groundwater and rainwater are distributed in a grid pattern below the basement floor 5 and along the periphery of the basement outer wall 6 through the drainage culvert 1. The water is then temporarily collected through the hidden water collection well 2 at the intersection of the drainage culvert 1. The water is then gradually drained through the drainage culvert 1 and the water collection well 2 to the precipitation well 3 at the four corners of the basement outer wall 6. The water level is controlled by a submersible pump 13 and a float valve 14 in the precipitation well 3. The water is then pumped through the pumping pipe 15 in the precipitation well to the water storage sedimentation tank on the outdoor ground 7 for comprehensive recycling. The drainage culvert 1 uses a pre-made ∩-shaped trough, which is positioned and pre-excavated according to the actual situation on site during the foundation pit excavation. The excavation surface at the bottom of the ∩-shaped trough extends 200mm beyond the trough on both sides. The lower soil is compacted mechanically or manually. A 100mm thick concrete cushion layer 8 is poured on the rammed soil layer 11, covered with a geotextile as a mud and sand barrier. A pebble layer 9 and a crushed stone layer 22 are laid at the bottom of the ∩-shaped trough as a filter layer. The ∩-shaped trough is then installed and fixed with M10.0 cement mortar. The longitudinal drainage slope of the ∩-shaped trough is 0.5%. Pebble layers 9 and crushed stone layers 22 are laid on both sides of the ∩-shaped trough to form a triangular accumulation 23 and covered with a geotextile as a mud and sand barrier. The ∩-shaped trough is then filled with a covering soil layer 12, and the basement floor construction process is carried out. Groundwater and rainwater from the foundation pit enter the drainage culvert 1 through blocks and are discharged to the collection well 2. The side walls of the water collection well 2 are constructed with sand-lime bricks, and the cover is a precast reinforced concrete slab. The concealed water collection well 2 measures 1.0m high, 1.0m wide, and 1.5m long. It is located at the intersection of the drainage culvert 1. A drainage well 3 is located around the basement exterior wall 6. This reinforced concrete structure utilizes the basement shear wall as its inner side. The bottom of the drainage well 3 is 3m lower than the basement floor elevation. The well measures 2m wide and 2m long, and descends 3m from the floor elevation to the outdoor ground level. The drainage well 3 was constructed simultaneously with the adjacent basement exterior wall 6. Groundwater and rainwater from the foundation pit are channeled through the drainage culvert 1 and the water collection well 2 to the drainage well 3. A submersible pump 13 of appropriate size is installed at the bottom of the precipitation well 3, based on the water volume. A DN100 galvanized steel pipe 15 is installed as a pumping pipe to pump water from the precipitation well 3 to a water storage and sedimentation tank 4 located outdoors on the ground 7. A float valve 14 controls the water level in the precipitation well 3. The water pumped to the water storage and sedimentation tank 4 undergoes sedimentation treatment, allowing for comprehensive water resource utilization based on actual on-site construction.

[0044] This invention effectively utilizes the concept of "combining drainage and comprehensive utilization" by channeling groundwater and rainwater from beneath the floor and around the basement's exterior walls into drainage wells, which are then pumped out to outdoor water storage and sedimentation tanks. This solves the drainage problem during foundation pit construction, speeds up construction, converts construction wastewater into recycled water for comprehensive water resource utilization, conserves water, reduces construction costs, lowers groundwater pressure, and prevents the risk of leakage from the basement floor and exterior walls, ensuring project quality.

Claims

1. A method for draining groundwater from the bottom and surrounding areas of a basement, characterized by: This method involves setting up vertical and horizontal intersecting drainage ditches around the basement and at the bottom. Collection wells are then set up at the intersections to temporarily collect water from the drainage ditches and direct it to precipitation wells located at the four corners of the basement's outer walls. Submersible pumps in the precipitation wells pump the water from the precipitation wells to outdoor ground-based water storage and sedimentation tanks, where the settled water is reused as construction water. The construction steps of the above method are as follows: a. When excavating the basement foundation pit, the foundation pit should be excavated to a depth of 200mm below the bottom surface of the basement floor; b. Continue digging at the four corners of the basement's outer wall to a depth of 3m below the basement floor elevation, and then use reinforced concrete to pour a drainage well in the deep pit; c. Tamp the bottom of the foundation pit to form a rammed soil layer; pour a 100mm thick concrete cushion layer on top of the rammed soil layer; d. Use gray bricks to build water collection wells on the concrete cushion layer. The water collection wells are arranged in rows and columns on the concrete cushion layer outside the basement floor and basement exterior wall to be poured; e. Lay the lower layer of geotextile on the concrete cushion, and lay the filter layer on the lower layer of geotextile; f. Install drainage ditches on the top surface of the filter layer, and connect all the water collection wells and the precipitation wells located at the four corners of the basement outer wall through the drainage ditches to form a drainage grid; g. Lay the upper geotextile on the top surface of the filter layer and drainage ditch; backfill the covering soil layer on the top surface of the upper geotextile to the bottom surface level of the basement floor and tamp it; h. Complete the concrete pouring construction of the basement floor and basement exterior wall on the top surface of the covering soil layer; backfill the soil outside the basement exterior wall to the outdoor ground level and tamp it; i. Construct a water storage and sedimentation tank on one side of the wellhead of the precipitation well; install a float valve and a submersible pump at the bottom of the precipitation well. The submersible pump pumps the water in the precipitation well to the water storage and sedimentation tank through the pumping pipe for reuse after sedimentation; The drainage ditch is laid with a finished ∩-shaped trough; the width of the lower mouth of the ∩-shaped trough is 400mm and the height is 500mm; a semicircular hole with a radius of 200mm is provided in the middle of the bottom of the two side walls of the ∩-shaped trough as a water inlet hole; when laying the drainage ditch, the connection between each section of the ∩-shaped trough and between the water collection well or precipitation well is connected with M10.0 cement mortar; the drainage ditch should be laid with the middle high and the four corners low to form a drainage slope of 0.5%.

2. The method for draining groundwater from the bottom and surrounding areas of a basement according to claim 1, characterized in that: The filter layer is composed of a pebble layer and a crushed stone layer. When the crushed stone layer is laid, the crushed stone layer forms an oblique triangle accumulation at the bottom of both sides of the drainage ditch. The top height of the triangular accumulation should cover the water inlet holes on both sides of the drainage ditch.

3. The method for draining groundwater from the bottom and surrounding areas of a basement according to claim 2, characterized in that: When laying the upper layer of geotextile on the gravel layer and the top surface of the drainage ditch, the geotextile should be laid close to the top surface of the drainage ditch and the triangular accumulation.

4. The method for draining groundwater from the bottom and surrounding areas of a basement according to claim 1, characterized in that: The pouring of the precipitation well adopts a segmented pouring method. During pouring, a steel ladder is embedded in the well wall on one side of the precipitation well; the first pouring height is higher than the elevation of the basement floor to be poured; after the construction of the rammed earth layer, concrete cushion layer, water collection well, lower geotextile, filter layer and upper geotextile is completed, the upper section of the precipitation well is poured to the ground elevation.

5. A basement bottom and surrounding groundwater drainage structure constructed according to the basement bottom and surrounding groundwater drainage method according to any one of claims 1 to 4, comprising precipitation wells (3) located at the four corners of the basement and a group of water collection wells (2) located below the basement floor (5) and outside the basement outer wall (6); characterized in that: A group of water collection wells (2) are connected to the precipitation wells (3) at the four corners of the basement via a drainage culvert (1); a submersible pump (13) and a float valve (14) are provided in the precipitation well (3); the submersible pump (13) is located on the bottom plate (19) of the precipitation well; the submersible pump (13) is connected to a water storage sedimentation tank (4) connected to the outdoor ground (7) via a pumping pipe (15).

6. The underground water drainage structure at the bottom and around the basement according to claim 5, characterized in that: The drainage ditch (1) is a connecting piece consisting of a group of ∩-shaped grooves; the lower opening of the ∩-shaped groove is 400 mm wide and 500 mm high; a water inlet hole (20) with a radius of 200 mm is provided in the middle of the bottom of the two side walls of the ∩-shaped groove.

7. The underground water drainage structure at the bottom and around the basement according to claim 5, characterized in that: An upper geotextile (21) is sequentially provided between the top of the drainage ditch (1) and the bottom surface of the basement floor (5) from bottom to top, and a covering soil layer (12) is provided on the top surface of the upper geotextile (21); a crushed stone layer (22), a pebble layer (9), a concrete cushion layer (8) and a rammed earth layer (11) are sequentially provided below the drainage ditch (1) from top to bottom; wherein the crushed stone layer (22) is provided with a triangular pile (23) outside the drainage ditch (1) to cover the water inlet (20) of the drainage ditch (1).

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