A dewatering device for soft soil layer super-large foundation pit earthwork excavation

Abstract

The utility model provides a kind of soft soil layer super-large foundation pit earthwork excavation uses precipitation device, including precipitation well, multiple the precipitation well is arranged in the side of foundation pit, multiple recharge well is arranged between the precipitation well and building;Sediment tank is connected by multiple high-pressure water pumps respectively the precipitation well and the recharge well;The top of the precipitation well and the recharge well is equipped with adjusting mechanism, the adjusting mechanism includes fixed cylinder, the top of the precipitation well and the recharge well is equipped with fixed cylinder, the top of the fixed cylinder is equipped with cylinder cover, multiple spring is installed between the cylinder cover and compression plate, the sidewall of the compression plate is equipped with sealing gasket, and the sealing gasket slidingly connects the inboard wall of the fixed cylinder;The return pipe is communicated the sediment tank, the sediment tank is communicated compression mechanism, and the compression mechanism is communicated the adjusting mechanism.The utility model provides the soft soil layer super-large foundation pit earthwork excavation uses precipitation device with the advantage that effectively slows down pipe well siltation.

Description

Technical Field

[0001] This utility model relates to the field of foundation pit dewatering technology, and in particular to a dewatering device for excavating large foundation pits in soft soil layers. Background Technology

[0002] Soft soil layers contain high moisture content and a large void ratio, typically exhibiting high compressibility and low shear strength. Since the area of ​​ultra-large foundation pits exceeds 10,000 square meters, groundwater from the soft soil layer continuously seeps into the pit during excavation, leading to accidents such as slope instability, quicksand in the foundation, pit bottom heave, piping at the pit bottom, and a decrease in foundation bearing capacity. Therefore, deep well point dewatering is employed. Deep well point dewatering has advantages such as large drainage capacity, large dewatering depth, and large dewatering range. Deep well point dewatering lowers the confined water level, helping to reduce pressure and ensure the safety of the foundation pit.

[0003] During the process of using deep well point dewatering, because the interior of the soft soil layer is a loose sand layer, under the action of dynamic water pressure, the fine sand particles flow with the water along the pores between the coarse particles into the well and continuously settle, causing siltation and reducing the dewatering efficiency.

[0004] Therefore, it is necessary to provide a new dewatering device for excavating large foundation pits in soft soil layers to solve the above problems. Utility Model Content

[0005] The technical problem solved by this utility model is to provide a dewatering device for excavating large foundation pits in soft soil layers that effectively reduces the accumulation of silt in wells.

[0006] To solve the above-mentioned technical problems, the present invention provides a dewatering device for excavation of large foundation pits in soft soil layers, comprising: dewatering wells, multiple dewatering wells disposed on one side of the foundation pit, and multiple recharge wells disposed between the dewatering wells and the building; a sedimentation tank connected to the dewatering wells and the recharge wells respectively via multiple high-pressure water pumps; an adjustment mechanism installed at the top of each of the dewatering wells and the recharge wells, the adjustment mechanism comprising a fixed cylinder, a fixed cylinder installed at the top of each of the dewatering wells and the recharge wells, a cylinder cover installed at the top of the fixed cylinder, multiple springs installed between the cylinder cover and a compression plate, a sealing gasket installed on the side wall of the compression plate, and the sealing gasket slidably connected to the inner side wall of the fixed cylinder; a limiting block installed at the bottom of the fixed cylinder, and an adjustment pipe and a return pipe installed on the surface of the cylinder cover, valves installed on the side walls of the adjustment pipe and the return pipe; the return pipe connecting to the sedimentation tank, the sedimentation tank connecting to the compression mechanism, and the compression mechanism connecting to the adjustment mechanism.

[0007] Preferably, both the dewatering well and the recharge well are composed of a gravel filling layer, a support rod, and a geotextile layer. A gravel filling layer is provided around the support rod, the side wall of the support rod is provided with multiple through holes, and the surface of the support rod is covered with a geotextile layer.

[0008] Preferably, a pumping pipe is installed inside the dewatering well, and a high-pressure water pump is installed at one end of the pumping pipe. The high-pressure water pump is connected to the interior of the sedimentation tank through a drain pipe.

[0009] Preferably, multiple first partitions are installed alternately inside the sedimentation tank, and a second partition with an arc-shaped sidewall is installed on one side of the sedimentation tank. Multiple baffles with a long semi-circular sidewall at one end are installed on the surface of the second partition, and the baffles are aligned with the water outlet end of the drain pipe.

[0010] Preferably, the high-pressure water pump is connected to the other side of the sedimentation tank, and a reinjection pipe is installed on the surface of the high-pressure water pump. The reinjection pipe is installed inside the reinjection well. A compression plate is slidably connected to the side walls of the reinjection pipe and the pumping pipe, and a sealing gasket is installed at the connection between the compression plate and the reinjection pipe and the pumping pipe.

[0011] Preferably, the compression mechanism includes a mounting box, a motor that drives the crank connecting rod to rotate is mounted on the surface of the mounting box, and a compression cylinder is mounted on the side wall of the mounting box; a piston is slidably connected inside the compression cylinder, the piston is rotatably connected to the crank connecting rod, and the diameter of the piston is smaller than the diameter of the compression plate; an adjusting pipe and a suction pipe are installed at one end of the compression cylinder, and the suction pipe communicates with the interior of the sedimentation tank.

[0012] Preferably, both the regulating pipe and the suction pipe are equipped with a closed cylinder and a fixing net inside, the surface of the fixing net abuts against the float, and the float engages with the closed cylinder, which has an internal funnel shape.

[0013] Compared with related technologies, the dewatering device for excavation of ultra-large foundation pits in soft soil layers provided by this utility model has the following beneficial effects:

[0014] This utility model provides a dewatering device for excavating large foundation pits in soft soil layers. While groundwater enters the dewatering well within the soft soil layer, groundwater that has been settled in the sedimentation tank flows back into the soft soil layer through the recharge well, maintaining a stable groundwater level and preventing uneven settlement of buildings around the foundation pit. After the groundwater enters the dewatering well, a high-pressure water pump extracts the accumulated water through the pumping pipe. During pumping, a compression mechanism forces water from the sedimentation tank into the fixed cylinder through the regulating pipe. The water pushes a compression plate downwards within the fixed cylinder, stretching the spring. The area around the compression plate... The sealing gasket maintains the seal around the compression plate, facilitating the compression plate to squeeze the water inside the fixed cylinder. The compression plate squeezes the water inside the fixed cylinder and the dewatering well, increasing the water pressure inside the dewatering well and slowing down the rate at which groundwater enters the dewatering well. By slowly dewatering through the dewatering well, the hydraulic head difference and hydraulic gradient in the soft soil layer are reduced, keeping the fine sand particles inside the soft soil layer below the critical state for quicksand, reducing the possibility of water and sand moving together, preventing fine sand from flowing into the dewatering well, and effectively slowing down the rate of siltation in the dewatering well. Furthermore, when groundwater is recharged through the recharge well, the compression plate regulates the water pressure inside the recharge well, facilitating the entry of groundwater into the soft soil layer. Attached Figure Description

[0015] Figure 1 A schematic diagram of a preferred embodiment of the dewatering device for excavation of ultra-large foundation pits in soft soil layers provided by this utility model;

[0016] Figure 2 for Figure 1 The diagram shows an enlarged view of the structure at point A.

[0017] Figure 3 for Figure 1 The diagram shows an enlarged view of the structure at point B.

[0018] Figure 4 for Figure 3 The diagram shows an enlarged view of the structure at point C.

[0019] Figure 5 for Figure 1 The diagram shows the internal structure of the sedimentation tank.

[0020] Numbered in the diagram: 1. Dewatering well, 11. Crushed stone filling layer, 12. Support rod, 13. Through hole, 14. Geotextile layer, 2. Recharge well, 21. Recharge pipe, 3. Sedimentation tank, 31. First partition, 32. Second partition, 33. Baffle, 4. High-pressure water pump, 41. Pumping pipe, 42. Drainage pipe, 5. Adjusting mechanism, 51. Fixed cylinder, 52. Compression plate, 53. Sealing gasket, 54. Limiting block, 55. Spring, 56. Cylinder cover, 57. Adjusting pipe, 58. Return pipe, 6. Valve, 7. Compression mechanism, 71. Mounting box, 72. Motor, 73. Crank connecting rod, 74. Piston, 75. Compression cylinder, 76. Suction pipe, 77. Sealed cylinder, 78. Float, 79. Fixing net, 8. Building, 9. Foundation pit. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Please see Figures 1 to 5 , Figure 1 A schematic diagram of a preferred embodiment of the dewatering device for excavation of ultra-large foundation pits in soft soil layers provided by this utility model; Figure 2 for Figure 1 The diagram shows an enlarged view of the structure at point A. Figure 3 for Figure 1 The diagram shows an enlarged view of the structure at point B. Figure 4 for Figure 3 The diagram shows an enlarged view of the structure at point C. Figure 5 for Figure 1 The diagram shows the internal structure of the sedimentation tank. The dewatering device for excavating a large foundation pit in soft soil includes: dewatering wells 1, multiple dewatering wells 1 are located on one side of the foundation pit 9, and multiple recharge wells 2 are located between the dewatering wells 1 and the building 8; both the dewatering wells 1 and the recharge wells 2 are composed of a gravel filling layer 11, support rods 12, and a geotextile layer 14. A gravel filling layer 11 is arranged around the support rods 12, and the sidewalls of the support rods 12 have multiple through holes 13. The surface of the support rods 12 is covered with a geotextile layer 14. During use, the geotextile layer 14 and the gravel filling layer 11 prevent sediment from entering the interior of the support rods 12, and facilitate the even flow of groundwater through the geotextile layer 14 and the gravel filling layer 11 into the soft soil layer or the interior of the support rods 12.

[0023] The sedimentation tank 3 is connected to the dewatering well 1 and the recharge well 2 respectively by multiple high-pressure water pumps 4; a pumping pipe 41 is installed inside the dewatering well 1, and a high-pressure water pump 4 is installed at one end of the pumping pipe 41. The high-pressure water pump 4 is connected to the interior of the sedimentation tank 3 through a drain pipe 42; after groundwater enters the interior of the dewatering well 1, the high-pressure water pump 4 pumps the water out of the interior of the dewatering well 1 through the pumping pipe 41, and then pumps the groundwater into the interior of the sedimentation tank 3 through the drain pipe 42.

[0024] The sedimentation tank 3 has multiple first partitions 31 installed in an alternating pattern inside. A second partition 32 with an arc-shaped sidewall is installed on one side of the sedimentation tank 3. Multiple baffles 33 with one long semi-circular sidewall are installed on the surface of the second partition 32, and these baffles 33 are aligned with the outlet end of the drain pipe 42. When water enters the sedimentation tank 3 through the drain pipe 42, it rushes towards the second partition 32. The water, in contact with the baffles 33, moves outwards along the sidewall of the baffles 33, colliding with each other. This reduces the impact force on the second partition 32 and slows the flow rate, allowing the water to move upwards along the arc-shaped sidewall of the second partition 32, facilitating the downward sedimentation of impurities. Furthermore, as the water moves within the sedimentation tank 3, it continuously moves up and down between the multiple first partitions 31, causing further sedimentation of impurities and reducing the amount of impurities in the water.

[0025] The high-pressure water pump 4 is connected to the other side of the sedimentation tank 3. A reinjection pipe 21 is installed on the surface of the high-pressure water pump 4, and the reinjection pipe 21 is installed inside the reinjection well 2. The settled water is pumped into the reinjection pipe 21 by the high-pressure water pump 4, and then enters the soft soil layer through the reinjection well 2 to maintain a stable groundwater level. A compression plate 52 is slidably connected to the side walls of the reinjection pipe 21 and the pumping pipe 41. Sealing gaskets 53 are installed at the connection points of the compression plate 52 with the reinjection pipe 21 and the pumping pipe 41. In order to keep the side wall of the compression plate 52 sealed by the sealing gaskets 53, it is convenient for the compression plate 52 to adjust the water pressure inside the fixed cylinder 51.

[0026] Both the dewatering well 1 and the recharge well 2 are equipped with adjusting mechanisms 5 at their top ends. Each adjusting mechanism 5 includes a fixed cylinder 51. A cylinder cover 56 is installed at the top of each cylinder 51. Multiple springs 55 are installed between the cylinder cover 56 and the compression plate 52. A sealing gasket 53 is installed on the side wall of the compression plate 52, and the sealing gasket 53 is slidably connected to the inner side wall of the fixed cylinder 51. A limiting block 54 is installed at the bottom end of the fixed cylinder 51. An adjusting pipe 57 and a return pipe 58 are installed on the surface of the cylinder cover 56. Valves 6 are installed on the side walls of both the adjusting pipe 57 and the return pipe 58. During pumping, the compression mechanism 7 operates to force water from the sedimentation tank 3 into the fixed cylinder 51 through the adjusting pipe 57. The water pushes the compression plate 52 downwards inside the fixed cylinder 51, stretching the springs 55. The compression plate 52 is surrounded by... The sealing gasket 53 maintains the seal around the compression plate 52, facilitating the compression plate 52 to squeeze the water inside the fixed cylinder 51. The compression plate 52 squeezes the water inside the fixed cylinder 51 and the dewatering well 1, increasing the water pressure inside the dewatering well 1 and slowing down the rate at which groundwater enters the dewatering well 1. By slowly lowering the water level through the dewatering well 1, the hydraulic head difference and hydraulic gradient in the soft soil layer are reduced, keeping the fine sand particles inside the soft soil layer below the critical state for quicksand, reducing the possibility of water and sand moving together, preventing fine sand from flowing into the dewatering well 1, and effectively slowing down the rate of siltation in the dewatering well 1. When the water pressure inside the dewatering well 1 is too high, the return pipe 58 is opened, and the spring 55 contracts, causing the compression plate 52 to move upward. The water above the compression plate 52 enters the sedimentation tank 3 through the return pipe 58, reducing the squeezing force of the compression plate 52 on the water and reducing the water pressure inside the dewatering well 1.

[0027] The return pipe 58 connects to the sedimentation tank 3, the sedimentation tank 3 connects to the compression mechanism 7, and the compression mechanism 7 connects to the adjustment mechanism 5. The compression mechanism 7 includes a mounting box 71, on the surface of which a motor 72 is mounted to drive the crank connecting rod 73 to rotate, and a compression cylinder 75 is mounted on the side wall of the mounting box 71. A piston 74 is slidably connected inside the compression cylinder 75, and the piston 74 is rotatably connected to the crank connecting rod 73. The diameter of the piston 74 is smaller than the diameter of the compression plate 52. To facilitate the movement of the piston 74, the compression cylinder 75 is... Water inside the fixed cylinder 51 is squeezed into the interior of the fixed cylinder 51, pushing the compression plate 52 downward to squeeze the water inside the fixed cylinder 51; one end of the compression cylinder 75 is equipped with the regulating pipe 57 and the suction pipe 76, and the suction pipe 76 is connected to the interior of the sedimentation tank 3; both the regulating pipe 57 and the suction pipe 76 are equipped with a closed cylinder 77 and a fixed net 79, the surface of the fixed net 79 abuts against the float 78, and the float 78 engages with the funnel-shaped closed cylinder 77; when water pressure needs to be adjusted, the motor 72 is turned on. 2 drives the crank connecting rod 73 to rotate, and the crank connecting rod 73 drives the piston 74 to move back and forth continuously in the compression cylinder 75; the fixed net 79, the float 78 and the closed cylinder 77 form a one-way valve. When the piston 74 moves towards the mounting box 71, suction is generated inside the compression cylinder 75. At this time, the float 78 inside the suction pipe 76 abuts against the fixed net 79, and the float 78 inside the regulating pipe 57 engages with the closed cylinder 77, sealing the inside of the regulating pipe 57, so that the sedimentation tank 3 is filled with water. Water enters the interior of the compression cylinder 75 through the suction pipe 76; when the piston 74 moves toward the regulating pipe 57, the water inside the compression cylinder 75 pushes the float 78 inside the suction pipe 76 to engage the sealing cylinder 77, and the float 78 inside the regulating pipe 57 abuts against the fixing net 79, sealing the interior of the suction pipe 76 and pushing the water inside the compression cylinder 75 into the regulating pipe 57. As the piston 74 continues to move, the water inside the sedimentation tank 3 is continuously pushed into the regulating pipe 57.

[0028] The working principle of this utility model is as follows: The device is connected to an external power source, and the high-pressure water pump 4 is turned on to pump water from the dewatering well 1 through the pumping pipe 41. Then, the groundwater is pumped into the sedimentation tank 3 through the drainage pipe 42. The water enters the sedimentation tank 3 and flows towards the second partition 32. Multiple baffles 33 with one sidewall of a semi-circular shape are installed on the surface of the second partition 32. The water contacts the baffles 33 and moves outwards along the sidewalls of the baffles 33, colliding with each other. This reduces the impact force on the second partition 32 and slows the flow rate, allowing the water to move upwards along the arc-shaped surface of the second partition 32, facilitating the downward sedimentation of impurities. Furthermore, as the water moves within the sedimentation tank 3, it continuously moves up and down between the multiple first partitions 31, causing further sedimentation of impurities and reducing their concentration. The settled water is then pumped by the high-pressure water pump 4 into the reinjection pipe 21, and then through the reinjection well 2 into the soft soil layer, maintaining a stable groundwater level. When it is necessary to increase the water pressure inside the dewatering well 1 or the reinjection well 2, the motor 72 is turned on. The motor 72 drives the crank connecting rod 73 to rotate, and the crank connecting rod 73 drives the piston 74 to move back and forth continuously in the compression cylinder 75, pushing the water inside the compression cylinder 75 into the regulating pipe 57. As the piston 74 moves continuously, it pushes the water inside the sedimentation tank 3 into the regulating pipe 57. The valve 6 on the side wall of the regulating pipe 57 is opened, and the water is forced into the fixed cylinder 51 through the regulating pipe 57. The water pushes the compression plate 52 to move downward inside the fixed cylinder 51, stretching the spring 55. The sealing gasket 53 around the compression plate 52 maintains the sealing around the compression plate 52, facilitating the compression plate 52 to squeeze the water inside the fixed cylinder 51. The compression plate 52 squeezes the fixed cylinder 51 and the dewatering well. The water pressure inside the dewatering well 1 increases, slowing down the rate at which groundwater enters the well. This slow water flow through the well reduces the head difference and hydraulic gradient in the soft soil layer, lowering the fine sand particles below the critical level for quicksand and reducing the likelihood of simultaneous water and sand movement. This prevents fine sand from flowing into the well and effectively slows down the siltation rate. When the water pressure inside the well 1 is too high, the return pipe 58 is opened, and the spring 55 contracts, causing the compression plate 52 to move upwards. Water above the compression plate 52 enters the sedimentation tank 3 through the return pipe 58, reducing the pressure exerted by the compression plate 52 on the water and decreasing the water pressure inside the well 1. Similarly, the water pressure inside the recharge well 2 is adjusted in the same way to facilitate water entering the soft soil layer, maintaining a stable groundwater level and effectively preventing uneven settlement of the building.

[0029] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A dewatering device for excavating large foundation pits in soft soil layers, characterized in that, include: The dewatering wells are arranged on one side of the foundation pit, and multiple recharge wells are arranged between the dewatering wells and the building. The sedimentation tank is connected to the dewatering well and the reinjection well via multiple high-pressure water pumps. Both the dewatering well and the recharge well are equipped with an adjustment mechanism at their top. The adjustment mechanism includes a fixed cylinder, and a cylinder cover is installed at the top of both the dewatering well and the recharge well. Multiple springs are installed between the cylinder cover and the compression plate. A sealing gasket is installed on the side wall of the compression plate, and the sealing gasket is slidably connected to the inner side wall of the fixed cylinder. A limiting block is installed at the bottom of the fixed cylinder, and an adjustment pipe and a return pipe are installed on the surface of the cylinder cover. Valves are installed on the side walls of both the adjustment pipe and the return pipe. The reflux pipe is connected to the sedimentation tank, the sedimentation tank is connected to the compression mechanism, and the compression mechanism is connected to the adjustment mechanism.

2. The dewatering device for excavation of ultra-large foundation pits in soft soil layers according to claim 1, characterized in that, Both the dewatering well and the recharge well are composed of a gravel filling layer, a support rod, and a geotextile layer. A gravel filling layer is provided around the support rod, the side wall of the support rod has multiple through holes, and the surface of the support rod is covered with a geotextile layer.

3. The dewatering device for excavation of ultra-large foundation pits in soft soil layers according to claim 2, characterized in that, A pumping pipe is installed inside the dewatering well, and a high-pressure water pump is installed at one end of the pumping pipe. The high-pressure water pump is connected to the interior of the sedimentation tank through a drain pipe.

4. The dewatering device for excavation of ultra-large foundation pits in soft soil layers according to claim 3, characterized in that, The sedimentation tank has multiple first partitions installed inside in an alternating pattern. A second partition with an arc-shaped sidewall is installed on one side of the sedimentation tank. Multiple baffles with a long semi-circular sidewall at one end are installed on the surface of the second partition, and the baffles are aligned with the water outlet end of the drain pipe.

5. The dewatering device for excavation of ultra-large foundation pits in soft soil layers according to claim 4, characterized in that, The high-pressure water pump is connected to the other side of the sedimentation tank. A reinjection pipe is installed on the surface of the high-pressure water pump and is installed inside the reinjection well. A compression plate is slidably connected to the side walls of the reinjection pipe and the pumping pipe. A sealing gasket is installed at the connection between the compression plate and the reinjection pipe and the pumping pipe.

6. The dewatering device for excavation of ultra-large foundation pits in soft soil layers according to claim 1, characterized in that, The compression mechanism includes a mounting box, on the surface of which a motor that drives the crank connecting rod to rotate is mounted, and a compression cylinder is mounted on the side wall of the mounting box; a piston is slidably connected inside the compression cylinder, and the piston is rotatably connected to the crank connecting rod, and the diameter of the piston is smaller than the diameter of the compression plate; an adjusting pipe and a suction pipe are mounted at one end of the compression cylinder, and the suction pipe communicates with the interior of the sedimentation tank.

7. The dewatering device for excavation of ultra-large foundation pits in soft soil layers according to claim 6, characterized in that, Both the regulating pipe and the suction pipe are equipped with a closed cylinder and a fixing net inside. The surface of the fixing net abuts against the float, and the float engages with the closed cylinder, which has a funnel-shaped interior.

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