Foundation pit dewatering well structure

Abstract

The foundation pit dewatering well structure is applied to the field of foundation pit dewatering facilities and comprises a dewatering well hole formed in a foundation and a well pipe arranged in the dewatering well hole, the depth of the dewatering well hole is larger than that of a foundation pit, the well pipe is composed of a bridge type water filtering pipe and a sand setting pipe, and the bridge type water filtering pipe is communicated with the sand setting pipe; a first filter screen is arranged at the bottom of the sand setting pipe, a first filter layer is arranged between the bottom of the dewatering well hole and the sand setting pipe, a second filter screen is arranged on the periphery of the bridge type filter pipe, the second filter screen and the bridge type filter pipe are arranged at intervals to form a sand setting area, and a second filter layer is arranged between the side wall of the dewatering well hole and the second filter screen. And the first filter layer and the second filter layer are filled gravel filter materials. On the basis of the filter layer filled with the gravel filter material and the bridge type filter pipe, the first filter screen is additionally arranged at the bottom of the well casing, and the second filter screen and the sand setting area are additionally arranged on the side face of the well casing, so that the filter capacity of the dewatering well can be improved, the amount of fine-particle silt entering the well casing is reduced, and normal operation of a water suction pump is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of foundation pit dewatering facilities, and in particular to a foundation pit dewatering well structure. Background Art

[0002] When excavating a foundation pit, the groundwater level is often higher than the bottom of the excavation pit, and groundwater will continuously seep into the pit. In order to ensure that the foundation pit can be constructed under dry conditions, a certain number of foundation pit dewatering wells can be set up around the foundation pit to collect groundwater in the dewatering wells. Pumping equipment can then be used to pump out the water in the wells to keep the soil in the foundation pit construction area dry, thereby preventing the foundation pit from experiencing slope instability, foundation sand flow, pit bottom uplift, pit bottom pipe gushing, and reduced foundation bearing capacity.

[0003] The existing foundation pit drainage well structure is to dig a hole on the foundation, and then lower a well pipe into the drainage well hole. The well pipe is composed of a bridge-type water filter pipe and a sand settling pipe at the bottom. Before lowering the well pipe, filter material must be filled at the bottom of the well hole. After the well pipe is lowered, the filter material between the sand settling pipe and the bottom of the well hole forms a filter layer that can be passed through by groundwater. At the same time, filter material is also filled between the side wall of the well pipe and the side wall of the well hole. The filter material between the bridge-type water filter pipe and the side wall of the well hole also forms a filter layer that can be passed through by groundwater. The filter layer is filled with gravel, but the filtration effect of the filter layer formed by gravel filling alone is not ideal. Even if the bridge-type water filter pipe itself is a water filtration device with filtration function, the overall filtration effect is difficult to meet the requirements. Fine particles of mud and sand can still enter the well pipe with groundwater, causing a burden on the operation of the water pump. Utility Model Content

[0004] In order to improve the defect that the filtering effect of existing foundation pit dewatering wells is not ideal, fine particles of sediment can still enter the well pipe along with groundwater, causing the operating burden of the water pump, the present application provides a foundation pit dewatering well structure.

[0005] The present application provides a foundation pit dewatering well structure, which adopts the following technical solution:

[0006] A foundation pit drainage well structure, comprising a drainage well hole arranged on a foundation and a well pipe arranged in the drainage well hole, the depth of the drainage well hole is greater than the depth of the foundation pit, the well pipe is composed of a bridge-type water filter pipe and a sand settling pipe, the bridge-type water filter pipe and the sand settling pipe are sequentially connected from top to bottom;

[0007] Among them, a first filter net is provided at the bottom of the sand settling pipe, a first filter layer is provided between the bottom of the precipitation wellbore and the sand settling pipe, a second filter net is provided on the outer periphery of the bridge-type water filter pipe, the second filter net and the bridge-type water filter pipe are spaced apart to form a sand settling area, a second filter layer is provided between the side wall of the precipitation wellbore and the second filter net, and the first filter layer and the second filter layer are both filled with gravel filter material.

[0008] By adopting the above technical solution, on the basis of the filter layer and bridge-type water filter pipe formed by filling gravel filter material, a first filter screen is added to the bottom of the well pipe, and a second filter screen and a sand settling area are added to the side of the well pipe, so as to improve the filtering capacity of the precipitation well filtration structure as a whole, reduce the amount of fine particles of sediment entering the well pipe with groundwater, so as to ensure the normal operation of the pump. Among them, the role of the sand settling area is that its function is the same as that of the sand settling pipe, and it can precipitate the sediment in the groundwater. The difference is that the sand settling pipe precipitates the sediment in the groundwater that enters the well pipe, while the sand settling area precipitates the sediment in the groundwater that has not entered the well pipe in the sand settling area, so as to achieve the effect of prior sedimentation and filtration, reduce the amount of sediment entering the well pipe, and thus reduce the operating burden of the pump.

[0009] Optionally, the particle size of the gravel filter material is 8-12 mm.

[0010] By adopting the above technical solution, the appropriate gravel particle size range can improve the filtering effect of the precipitation well.

[0011] Optionally, the mesh size of the first filter is 1.5-3 mm, and the mesh size of the second filter is also 1.5-3 mm.

[0012] By adopting the above technical solution, on the basis of the primary filtration of the gravel filter material, the filter net performs secondary filtration, and the filtration accuracy is better than that of the gravel filter material, thereby improving the sand filtering effect of the precipitation well. The setting of the second filter net also plays the role of separating the gravel filter material and the well pipe and forming a sand settling area. After the primary and secondary filtration, the silt in the groundwater is precipitated and filtered in the sand settling area, and the overall filtration effect will be better.

[0013] Optionally, the bridge hole gap of the bridge type water filter pipe is 0.5-2.5mm.

[0014] By adopting the above technical solution, the bridge-type water filter pipe is used as the final filtering step. The appropriate bridge hole gap range can improve the filtering effect of the precipitation well, and the filtering accuracy of the bridge-type water filter pipe is better than that of the filter net.

[0015] Optionally, the second filter screen extends downward to the sand settling pipe, so the sand settling area also extends downward to the sand settling pipe.

[0016] By adopting the above technical solution, since the wall of the sand settling pipe is different from that of the bridge-type water filter pipe and has a non-porous structure, the sand settling area is extended downward to the sand settling pipe. In this way, the precipitated sand will be better stored at the bottom of the sand settling area and will not easily enter the well pipe through the gap of the bridge hole.

[0017] Optionally, the radial space of the sand settling area at the sand settling pipe is larger than the radial space at the bridge-type water filter pipe.

[0018] By adopting the above technical solution, the sedimentation and storage capacity of the sand settling area can be increased.

[0019] Optionally, the length of the bridge-type water filter pipe extending out of the wellhead of the precipitation wellbore is 0.15-0.3m, and a sealing cover is provided on the top of the bridge-type water filter pipe.

[0020] By adopting the above technical solution, the bridge filter pipe extends out of the wellhead of the precipitation well hole, which can prevent surface sewage from flowing into the well pipe. The cover is used to seal the top of the bridge filter pipe to prevent foreign objects from falling into the well pipe during construction, and can also improve the safety of construction area operations.

[0021] Optionally, the cover is detachably fixed to the top of the bridge-type water filter pipe, wherein a notch is provided at the edge of the cover for the water suction pipe to pass through.

[0022] By adopting the above technical solution, the cover can be detachably fixed on the top of the bridge-type water filter pipe, and a notch for the pumping pipe to pass through is provided at the edge of the cover, thereby facilitating the installation and use of the pumping pump and the pumping pipe in the well pipe.

[0023] In summary, this application includes the following beneficial technical effects:

[0024] 1. On the basis of the filter layer formed by gravel filter material and the bridge-type water filter pipe, a first filter screen is added to the bottom of the well pipe, and a second filter screen and a sand settling area are added to the side of the well pipe, so as to improve the filtering capacity of the precipitation well filter structure as a whole and reduce the amount of fine particles of sand entering the well pipe with groundwater, thereby ensuring the normal operation of the water pump.

[0025] 2. The function of the sand settling area is the same as that of the sand settling pipe, which can precipitate the silt in the groundwater. The difference is that the sand settling pipe precipitates the silt in the groundwater that enters the well pipe, while the sand settling area precipitates the silt in the groundwater that is in the sand settling area but has not yet entered the well pipe, thereby achieving the effect of prior precipitation and filtration, reducing the amount of silt entering the well pipe, thereby reducing the operating burden of the pump. At the same time, the sand settling area is extended downward to the sand settling pipe, so that the precipitated silt will be better stored at the bottom of the sand settling area, and it is not easy to enter the well pipe through the gap of the bridge hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the foundation pit dewatering well structure in an embodiment of the present application.

[0027] Figure numerals: 1. precipitation well hole; 2. well pipe; 21. bridge-type water filter pipe; 22. sand settling pipe; 3. first filter screen; 4. second filter screen; 5. first filter layer; 6. second filter layer; 7. sand settling area; 8. cover; 81. gap. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1 This application is described in further detail.

[0029] The present application embodiment discloses a foundation pit dewatering well structure, referring to Figure 1 The foundation pit drainage well structure includes a drainage well hole 1 arranged on the foundation and a well pipe 2 arranged in the drainage well hole 1. The depth of the drainage well hole 1 is set to h, and the depth of the foundation pit is set to H, then h>H. Before lowering the well pipe 2 into the drainage well hole 1, gravel filter material must be filled at the bottom of the drainage well hole 1. The gravel filter material at this position is the first filter layer 5. The well pipe 2 is composed of a bridge-type water filter pipe 21 and a sand settling pipe 22 at the bottom of the bridge-type water filter pipe 21. The bridge-type water filter pipe 21 and the sand settling pipe 22 can be welded or fixed by clamping or screwing. The bridge-type water filter pipe 21 and the sand settling pipe 22 are coaxial and connected. The length of the sand settling pipe 22 is 0.3-0.5m. After the well pipe 2 is lowered into the precipitation well hole 1, the sand settling pipe 22 lands on the gravel filter material at the bottom of the precipitation well hole 1, so that the first filter layer 5 between the bottom of the sand settling pipe 22 and the bottom of the precipitation well hole 1 can play a role in sand blocking and filtering. In addition, a first filter net 3 is provided at the bottom of the sand settling pipe 22. The first filter net 3 not only plays a role in blocking the gravel filter material from entering the well pipe 2, but also mainly plays a role in increasing the ability of the bottom of the well pipe 2 to filter sediment.

[0030] Reference Figure 1 After the well pipe 2 is lowered, the length of the bridge filter pipe 21 extending out of the wellhead of the precipitation well hole 1 is 0.15-0.3m. The purpose of this design is to prevent surface sewage from flowing into the well pipe 2.

[0031] Reference Figure 1Furthermore, a second filter screen 4 is provided on the periphery of the well pipe 2. The second filter screen 4 is arranged around the well pipe 2 and keeps a distance from the well pipe 2 to form a sand settling area 7 between the two. The sand settling area 7 can be used for sedimentation of groundwater when passing through. It should be emphasized here that the upper and lower ends of the second filter screen 4 are welded and fixed to the outer wall of the well pipe 2. The second filter screen 4 extends downward to the sand settling pipe 22 and extends upward to the wellhead where the bridge-type water filter pipe 21 does not extend out of the precipitation wellbore 1. The purpose of this design is that the sand settling area 7 can cover the area where the sand settling pipe 22 is located. Since the wall of the sand settling pipe 22 is a non-porous structure, which is different from the wall structure of the bridge-type water filter pipe 21, the precipitated sediment can be better stored at the bottom of the sand settling area 7, and it is not easy to pass through the bridge hole gap of the bridge-type water filter pipe 21 and enter the well pipe 2. In addition, the radial space of the sand settling area 7 at the sand settling pipe 22 is larger than the radial space at the bridge-type water filter pipe 21, which can improve the sand storage capacity at the bottom of the sand settling area 7, thereby extending the service life of the sand settling area 7.

[0032] Reference Figure 1 After the well pipe 2 is lowered, there is a gap between the second filter screen 4 and the side wall of the precipitation well hole 1. Gravel filter material is filled between the second filter screen 4 and the side wall of the precipitation well hole 1. The gravel filter material in this part is the second filter layer 6, which can also play a role in sand blocking and filtering. It should be emphasized here that the gravel filter material in this part can actually be completely mixed with the gravel filter material at the bottom of the precipitation well hole 1, and there is no clear dividing line between the two gravel filter materials.

[0033] Reference Figure 1 Specifically, the particle size of the gravel filter material filled in the first filter layer 5 and the second filter layer 6 is 8-12 mm, and the mesh size of the first filter screen 3 and the second filter screen 4 is 1.5-3 mm, preferably 2.5 mm, which can not only filter but also block the gravel filter material. The gap of the bridge hole of the bridge filter pipe 21 is 0.5-2.5 mm, preferably 1.5 mm. The filtering accuracy of the bridge filter pipe 21 is better than that of the filter screen.

[0034] For the bottom of the well pipe 2, the groundwater must first pass through the first filter layer 5 filled with 8-12mm gravel filter material, and then pass through the first filter screen 3 with a mesh size of 2.5mm. After two filtrations, it finally enters the well pipe 2. For the side of the well pipe 2, the groundwater must first pass through the second filter layer 6 filled with 8-12mm gravel filter material, and then pass through the second filter screen 4 with a mesh size of 2.5mm, and then pass through the sand settling area 7 to precipitate and filter the silt in the groundwater, and then pass through the bridge-type water filter pipe 21 with a bridge hole gap of 1.5mm. After four filtrations, it finally enters the well pipe 2. In addition, the silt in the groundwater in the well pipe 2 that has not been precipitated and filtered before can also be precipitated again in the sand settling pipe 22. Therefore, the ability of the foundation pit dewatering well of the present application to filter silt in groundwater is relatively ideal compared with the prior art. The overall filtering effect can meet the requirements, and the amount of fine silt in the groundwater entering the well pipe 2 can be significantly reduced, thereby reducing the burden on the pump and ensuring that the pump can operate normally.

[0035] Reference Figure 1 A cover 8 is provided on the top of the bridge filter pipe 21. The cover 8 can be detachably fixed by bolts. During construction, the cover 8 seals the top of the bridge filter pipe 21 to prevent foreign objects from falling into the well pipe 2 during construction, which can also improve the safety of construction area operations. In addition, a notch 81 is provided at the edge of the cover 8 for the pumping pipe to pass through. During construction, the cover 8 can be opened first, the pumping pump can be placed in the well pipe 2, and then the cover 8 can be closed, and the pumping pipe can pass through the notch 81 at the edge of the cover 8.

[0036] The implementation principle of a foundation pit drainage well structure in an embodiment of the present application is as follows: on the basis of a filter layer formed by filling gravel filter material and a bridge-type water filter pipe 21, a first filter screen 3 is added to the bottom of the well pipe 2, and a second filter screen 4 and a sand settling area 7 are added to the side of the well pipe 2, thereby being able to improve the filtering capacity of the drainage well filter structure as a whole and reduce the amount of fine particles of sediment that enter the well pipe 2 along with groundwater, thereby ensuring that the water pump can operate normally.

[0037] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A foundation pit dewatering well structure, characterized in that: It comprises a drainage well hole (1) arranged on a foundation and a well pipe (2) arranged in the drainage well hole (1), the depth of the drainage well hole (1) is greater than the depth of the foundation pit, the well pipe (2) is composed of a bridge-type water filter pipe (21) and a sand settling pipe (22), and the bridge-type water filter pipe (21) and the sand settling pipe (22) are sequentially connected from top to bottom; A first filter screen (3) is provided at the bottom of the sand settling pipe (22), a first filter layer (5) is provided between the bottom of the precipitation wellbore (1) and the sand settling pipe (22), a second filter screen (4) is provided on the periphery of the bridge-type water filter pipe (21), the second filter screen (4) and the bridge-type water filter pipe (21) are spaced apart to form a sand settling area (7), a second filter layer (6) is provided between the side wall of the precipitation wellbore (1) and the second filter screen (4), and the first filter layer (5) and the second filter layer (6) are both filled with gravel filter material.

2. A foundation pit dewatering well structure as claimed in claim 1, characterized in that: The particle size of the gravel filter material is 8-12 mm.

3. A foundation pit dewatering well structure as claimed in claim 1, characterized in that: The mesh diameter of the first filter screen (3) is 1.5-3 mm, and the mesh diameter of the second filter screen (4) is also 1.5-3 mm.

4. A foundation pit dewatering well structure as claimed in claim 1, characterized in that: The bridge hole gap of the bridge type water filter pipe (21) is 0.5-2.5 mm.

5. The foundation pit dewatering well structure according to claim 1, characterized in that: The second filter screen (4) extends downward to the sand settling pipe (22), so the sand settling area (7) also extends downward to the sand settling pipe (22).

6. A foundation pit dewatering well structure as claimed in claim 5, characterized in that: The radial space of the sand settling area (7) at the sand settling pipe (22) is larger than the radial space at the bridge-type water filter pipe (21).

7. The foundation pit dewatering well structure according to claim 1, characterized in that: The length of the portion of the bridge-type water filter pipe (21) extending out of the wellhead of the precipitation wellbore (1) is 0.15-0.3 m, and a sealing cover (8) is provided on the top of the bridge-type water filter pipe (21).

8. A foundation pit dewatering well structure as claimed in claim 7, characterized in that: The sealing cover (8) is detachably fixed to the top of the bridge-type water filter pipe (21), wherein a notch (81) is provided at the edge of the sealing cover (8) for the water suction pipe to pass through.

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