Deep foundation pit dewatering structure for near water hose and construction method

Abstract

The invention discloses a deep foundation pit dewatering structure used for a near water hose and a construction method of the deep foundation pit dewatering structure used for the near water hose, the deep foundation pit dewatering structure used for the near water hose comprises a surrounding retaining wall, a dewatering well, a filtering barrel and a drainage pipe, the surrounding retaining wall extends along the periphery of a deep foundation pit, the surrounding retaining wall is in a closed ring shape, and the dewatering well is arranged in the surrounding retaining wall. The depth of the part, inserted into the foundation, of the retaining wall is larger than that of the deep foundation pit; the dewatering well is located on the inner side of the retaining wall; the filtering barrel is inserted into the dewatering well, water filtering holes are formed in the barrel wall of the filtering barrel, and a filtering layer is arranged between the filtering barrel and the well wall of the dewatering well; the top end of the drainage pipe is detachably connected with a water pumping mechanism, and the lower end of the drainage pipe is provided with a combined filtering piece. Deformation or settlement of the side wall of the deep foundation pit caused by local water level difference is avoided, and the overall structural stability of the deep foundation pit in the follow-up construction process is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of house building structure, and particularly relates to a deep foundation pit dewatering structure for a water belt and a construction method. BACKGROUND

[0002] In the field of building engineering, deep foundation pit construction is a core pre-link of high-rise buildings, underground garages, subway tunnels and other projects, and the dryness of the construction environment directly determines the safety of the foundation pit excavation, the construction precision of the structure and the overall progress of the project. Due to the high underground water level of most building sites, underground water is easy to flow into the pit after the foundation pit is excavated, which leads to problems such as instability of the foundation pit slope, uplift of the foundation, and inability of construction machinery to work. The existing deep foundation pit dewatering system generally has problems such as poor water interception effect, low pumping efficiency, high maintenance cost, and high construction risk, and it is difficult to meet the requirements of modern building engineering for the safety, efficiency and economy of the foundation pit construction. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a deep foundation pit dewatering structure for a water belt, which can ensure the overall stability of the structure during the subsequent construction of the deep foundation pit.

[0004] The present application also provides a construction method for the deep foundation pit dewatering structure for a water belt.

[0005] The deep foundation pit dewatering structure for a water belt according to the first aspect of the present application comprises a retaining wall, a dewatering well, a filter barrel and a drain pipe. The retaining wall is arranged along the periphery of the deep foundation pit. The retaining wall is in the form of a closed ring and encloses the deep foundation pit. The depth of the retaining wall inserted into the foundation is greater than the depth of the deep foundation pit. The dewatering well is located on the inner side of the retaining wall. A plurality of dewatering wells are arranged along the extension direction of the retaining wall. The filter barrel and the dewatering well correspond to each other. The filter barrel is inserted into the dewatering well. The barrel wall of the filter barrel is provided with a water filtering hole. A filter layer is arranged between the filter barrel and the well wall of the dewatering well. The drain pipe is embedded in the filter barrel. The drain pipe and the filter barrel are detachably connected. The top end of the drain pipe is detachably connected with a water pumping mechanism. The lower end of the drain pipe is deep into the bottom of the filter barrel. The lower end of the drain pipe is provided with a combined filter.

[0006] The deep foundation pit dewatering structure for a water belt according to the present application has at least the following beneficial effects. The plurality of dewatering wells arranged along the extension direction of the retaining wall can uniformly extract the underground water in the deep foundation pit from multiple points, balance the water pressure in each area of the deep foundation pit, avoid the deformation or settlement of the deep foundation pit sidewall caused by local water level difference, and ensure the overall stability of the structure during the subsequent construction of the deep foundation pit.

[0007] According to some embodiments of the present application, the lower part of the enclosing wall is connected with rotary jet piles, the rotary jet piles are arranged continuously along the extending direction of the enclosing wall, the top of the rotary jet pile is provided with a groove, and the lower end of the enclosing wall is provided with a protrusion which is embedded in the groove.

[0008] According to some embodiments of the present application, the width of the groove is 1 / 2 to 1 / 3 of the width of the rotary jet pile.

[0009] According to some embodiments of the present application, further comprising a cushion layer, a waterproof layer and a protective bottom layer, the cushion layer covers the surface of the bottom of the deep foundation pit, the cushion layer is made of concrete; the waterproof layer covers the surface of the cushion layer, the waterproof layer is made of SBS waterproof coiled material; the protective bottom layer covers the surface of the waterproof layer, the protective bottom layer is made of fine stone concrete; wherein the pipe body of the drainage pipe is provided with a first water stop ring and a second water stop ring, the first water stop ring is fixedly connected with the cushion layer and covers the dewatering well; the second water stop ring is fixedly connected with the protective bottom layer, and the second water stop ring is located above the first water stop ring.

[0010] According to some embodiments of the present application, the waterproof layer wraps the outer wall of the drainage pipe, and the waterproof layer extends to abut against the second water stop ring.

[0011] According to some embodiments of the present application, the filter layer is made of a mixture of gravel and sand.

[0012] According to some embodiments of the present application, the drainage pipe is provided with a plurality of water-permeable holes in the part embedded in the filter barrel, the plurality of water-permeable holes are distributed in a matrix on the pipe wall of the drainage pipe, and the water-permeable holes are covered with non-woven fabric.

[0013] According to some embodiments of the present application, the combined filter member comprises a filter screen, a filter sponge and a limiting screen, and the filter screen, the filter sponge and the limiting screen are arranged in layers from top to bottom.

[0014] According to some embodiments of the present application, the water pumping mechanism comprises a water pump and a hose, two ends of the hose are fixedly connected with the water pump and the upper end of the drainage pipe respectively, the filter barrel is embedded with a water level sensor, the water level sensor is electrically connected with the pump, and the output power of the pump is controlled by the water level sensor.

[0015] According to the construction method of the second aspect of the present application, for constructing the deep foundation pit dewatering structure for the near water area of the first aspect of the present application, the method comprises the following steps:

[0016] Step 1, construction of a surrounding wall: first, measure and mark the surrounding wall construction boundary around the deep foundation pit; the surrounding wall is constructed by using steel sheet piles, continuous concrete walls and other technologies along the boundary to ensure that the surrounding wall is in the form of a closed ring and wraps the deep foundation pit, and the depth of the surrounding wall inserted into the foundation is greater than the depth of the deep foundation pit; after construction, check the sealing and verticality of the surrounding wall to avoid gaps or tilting;

[0017] Step 2, construction of a dewatering well: mark multiple dewatering well points in the inner side area of the surrounding wall according to the preset interval distance to ensure that the points are evenly distributed along the extension direction of the surrounding wall; drill holes at the marked points using drilling machinery, and the drilling depth needs to meet the groundwater extraction requirements; after the hole is formed, the hole is cleaned to form a dewatering well;

[0018] Step 3, installation of a filter barrel and a filter layer: prepare a filter barrel matching the dewatering well, insert the filter barrel into each dewatering well one by one, adjust the position of the filter barrel to form a uniform gap between the barrel wall and the well wall, and fill the filter layer in layers into the gap, and lightly compact each layer after filling to ensure that the filter layer is fully filled and the filter holes are not blocked;

[0019] Step 4, installation of a drainage pipe: install a combined filter at the lower end of the drainage pipe, and then embed the drainage pipe into the filter barrel, so that the lower end of the drainage pipe is deep into the bottom of the filter barrel;

[0020] Step 5, connection of a water pumping mechanism and debugging: the water pumping mechanism is connected to the top end of the drainage pipe through a detachable connection; after checking the sealing of the components, the water pumping mechanism is started for trial operation, and it is observed whether the groundwater flows into the drainage pipe through the filter layer, the filter hole of the filter barrel, the combined filter and is pumped out, and at the same time, the water level in the deep foundation pit is monitored to ensure that the construction effect meets the requirements.

[0021] According to the construction method of the embodiment of the present application, at least the following beneficial effects are obtained: the multiple dewatering wells arranged along the extension direction of the surrounding wall uniformly extract the groundwater in the deep foundation pit from multiple points, balance the water pressure in each area of the deep foundation pit, avoid the deformation or settlement of the side wall of the deep foundation pit caused by local water level difference, and ensure the overall stability of the structure in the subsequent construction process of the deep foundation pit.

[0022] Additional aspects and advantages of the application will be described in part in the following description, some of which will become apparent, or will be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0023] The application will be further described below in conjunction with the drawings and examples, in which:

[0024] Figure 1 FIG. 1 is a schematic view of a deep foundation pit dewatering structure for a near water zone according to an embodiment of the present application;

[0025] Figure 2 For Figure 1 An enlarged schematic view of part A is shown.

[0026] 100, enclosing wall; 110, protrusion;

[0027] 200, dewatering well;

[0028] 300, filter barrel; 310, water filtering hole; 320, filter layer;

[0029] 400, drain pipe; 401, first water stop ring; 402, second water stop ring; 403, water permeable hole; 410, water pumping mechanism; 411, water pump; 412, hose; 420, combined filter; 421, filter screen; 422, filter sponge; 423, limiting screen;

[0030] 500, rotary jet pile; 510, groove;

[0031] 600, cushion layer;

[0032] 700, waterproof layer;

[0033] 800, protective bottom layer; DETAILED DESCRIPTION

[0034] Embodiments of the present application are described in detail below with reference to the attached drawings, which show by way of example, embodiments in which the same or similar elements or elements having the same or similar functions are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and should not be understood as limiting the present application.

[0035] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be understood as limiting the present application.

[0036] In the description of the present application, several meanings are one or more, and multiple meanings are two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If the first, second, etc. are described, they are only used for the purpose of distinguishing technical features, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0037] In the description of the present application, unless otherwise explicitly defined, the words such as arrangement, installation, connection and the like should be understood broadly, and the person skilled in the art can determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0038] Referring to Figures 1 to 2 The deep foundation pit dewatering structure for the near water belt in the embodiment of the present application comprises a coffer wall 100, a dewatering well 200, a filter barrel 300 and a drain pipe 400. The coffer wall 100 is arranged along the periphery of the deep foundation pit. The coffer wall 100 is in the form of a closed ring and wraps the deep foundation pit. The depth of insertion of the coffer wall 100 into the foundation is greater than the depth of the deep foundation pit. The dewatering well 200 is located on the inner side of the coffer wall 100. A plurality of dewatering wells 200 are arranged. The plurality of dewatering wells 200 are arranged at intervals along the extension direction of the coffer wall 100. The filter barrel 300 and the dewatering well 200 correspond to each other. The filter barrel 300 is inserted into the dewatering well 200. The barrel wall of the filter barrel 300 is provided with a water filtering hole 310. A filter layer 320 is arranged between the barrel wall of the filter barrel 300 and the well wall of the dewatering well 200. The drain pipe 400 is embedded in the filter barrel 300. The drain pipe 400 and the filter barrel 300 are detachably connected. The top end of the drain pipe 400 is detachably connected with a water pumping mechanism 410. The lower end of the drain pipe 400 is deep into the bottom of the filter barrel 300. The lower end of the drain pipe 400 is provided with a combined filter 420.

[0039] In actual construction, the construction method for constructing the deep foundation pit dewatering structure of the embodiment comprises the following steps:

[0040] Step 1, construction of the coffer wall 100: first, measure and mark the periphery of the deep foundation pit to determine the construction boundary of the coffer wall 100; use steel sheet piles, concrete continuous walls and other processes to construct the coffer wall 100 along the boundary to ensure that the coffer wall 100 is in the form of a closed ring wrapping the deep foundation pit and the depth of insertion of the coffer wall 100 into the foundation is greater than the depth of the deep foundation pit; after construction, check the closure and verticality of the coffer wall 100 to avoid gaps or tilting;

[0041] Step 2, construction of the dewatering well 200: in the area on the inner side of the coffer wall 100, mark a plurality of dewatering well 200 points according to the preset interval distance to ensure that the points are uniformly distributed along the extension direction of the coffer wall 100; use drilling machinery to drill holes at the marked points. The drilling depth needs to meet the underground water pumping requirements. After the hole is formed, the hole is cleaned to form the dewatering well 200;

[0042] Step 3, install filter barrel 300 and fill filter layer 320: prepare filter barrels 300 matching the specifications of dewatering wells 200, insert filter barrels 300 into each dewatering well 200 one by one, adjust the position of filter barrels 300 to form a uniform gap between the barrel wall and the well wall of dewatering well 200; fill the gap with filter layer 320 in layers, and lightly compact each layer after filling to ensure that the filter layer 320 is filled and the filter water hole 310 is not blocked;

[0043] Step 4, install drain pipe 400: install combined filter 420 at the lower end of drain pipe 400, and then embed drain pipe 400 into filter barrel 300, so that the lower end of drain pipe 400 is deep into the bottom of filter barrel 300;

[0044] Step 5, connect water pumping mechanism 410 and debug: connect water pumping mechanism 410 to the top end of drain pipe 400 by detachable connection; after checking the sealing of each part, start the water pumping mechanism 410 for trial operation, observe whether the underground water passes through filter layer 320, filter water hole 310 of filter barrel 300, combined filter 420 into drain pipe 400 and is pumped out in turn, and monitor the water level drop in deep foundation pit to ensure that the construction effect meets the requirements.

[0045] After the above structure is constructed, the underground water in the foundation pit seeps into the dewatering well 200 with a lower water level; the underground water first passes through the filter layer 320 between the filter barrel 300 and the well wall of the dewatering well 200, and preliminarily intercepts large-particle silt impurities; then passes through the filter water hole 310 of the barrel wall of the filter barrel 300 into the inside of the filter barrel 300; then the underground water contacts the combined filter 420 at the lower end of the drain pipe 400, and further filters small impurities; finally, the water pumping mechanism 410 is started, a negative pressure is formed in the drain pipe 400, the filtered underground water is pumped out of the foundation pit along the drain pipe 400, and the water level in the foundation pit is lowered; wherein the closed ring design and depth control of the enclosing wall 100 can block the lateral seepage of underground water outside the foundation pit, and prevent the water level in the foundation pit from abnormally rising; the multiple dewatering wells 200 arranged at intervals can form a uniform water level drawdown funnel, and ensure that the water level in each area of the foundation pit drops synchronously; the multi-layer filter structure of filter layer 320 + filter water hole 310 + combined filter 420 can effectively intercept silt impurities in the underground water, and prevent the drain pipe 400 from being blocked.

[0046] In some embodiments, reference is made to Figure 1The lower part of the enclosing wall 100 is connected with a rotary jet pile 500, the rotary jet pile 500 is continuously arranged along the extension direction of the enclosing wall 100, the top of the rotary jet pile 500 is provided with a groove 510, the low end of the enclosing wall 100 is provided with a protrusion 110, and the protrusion 110 is embedded in the groove 510. The boundary line is designed along the enclosing wall 100, the high-pressure rotary jet drilling machine is used to drill a hole, the cement slurry is sprayed into the hole and rotated and lifted to form a continuous rotary jet pile 500, the groove 510 is reserved at the top of the rotary jet pile 500, and the protrusion 110 is prefabricated at the low end of the enclosing wall 100. After the rotary jet pile 500 is cured to the strength standard, the protrusion 110 of the enclosing wall 100 is aligned with the groove 510 of the rotary jet pile 500, and the protrusion 110 is slowly lowered to be embedded in the groove 510 to form a connection. The continuous rotary jet pile 500 enhances the foundation bearing capacity of the lower part of the enclosing wall 100 and avoids the settlement of the enclosing wall 100; the concave-convex embedded connection improves the connection strength of the enclosing wall 100 and the rotary jet pile 500 and prevents the separation of the two; the rotary jet pile 500 and the enclosing wall 100 cooperate to enhance the overall water-blocking effect and avoid the leakage of underground water from the connection between the enclosing wall 100 and the rotary jet pile 500. Specifically, the width of the groove 510 is 1 / 2 to 1 / 3 of the width of the rotary jet pile 500. If the width of the groove 510 is too narrow (<1 / 3 of the width of the rotary jet pile 500), the embedded depth of the protrusion 110 will be insufficient, and the connection strength will be low; if the width is too wide (>1 / 2 of the width of the rotary jet pile 500), the effective stress section of the top of the rotary jet pile 500 will be too small, and the rotary jet pile 500 is easy to crack when bearing the load of the enclosing wall 100; the ratio of 1 / 2 to 1 / 3 can balance the “embedded strength” and the “strength of the pile body” itself.

[0047] In some embodiments, with reference to Figure 1 , the deep foundation pit further comprises a cushion layer 600, a waterproof layer 700 and a protective bottom layer 800, the cushion layer 600 is made of concrete and covers the surface of the bottom of the deep foundation pit, the waterproof layer 700 is made of SBS waterproof coiled material and covers the surface of the cushion layer 600, and the protective bottom layer 800 is made of fine stone concrete and covers the surface of the waterproof layer 700; wherein the pipe body of the drainage pipe 400 is provided with a first water stop ring 401 and a second water stop ring 402, the first water stop ring 401 is fixedly connected with the cushion layer 600 and covers the dewatering well 200, and the second water stop ring 402 is fixedly connected with the protective bottom layer 800 and is located above the first water stop ring 401.

[0048] As a further optimization of the above construction method, in the present embodiment, a pre-step needs to be performed before step 1, the pre-step comprising:

[0049] Cushion layer 600 construction: after the deep foundation pit is excavated to the designed bottom elevation, the bottom surface is leveled, and the cushion layer 600 made of concrete is poured and constructed;

[0050] First water stop ring 401 installation: Fix the first water stop ring 401 at the position corresponding to the cushion layer 600 of the drain pipe 400, fix the first water stop ring 401 and the cushion layer 600 through expansion bolts, and ensure that the first water stop ring 401 completely covers the wellhead of the dewatering well 200;

[0051] Waterproof layer 700 construction: Lay SBS waterproof coiled material on the surface of the cushion layer 600, and paste it by hot melting method to ensure that it is tightly attached to the cushion layer 600;

[0052] Protection layer 800 construction: Pour the protection layer 800 made of fine stone concrete on the surface of the waterproof layer 700;

[0053] Second water stop ring 402 installation: Fix the second water stop ring 402 at the position corresponding to the protection layer 800 of the drain pipe 400, fix the second water stop ring 402 and the protection layer 800 through expansion bolts, and ensure that it is located above the first water stop ring 401.

[0054] Wherein, when step 4 is performed, the drain pipe 400 passes through the first water stop ring 401 and the second water stop ring 402 from top to bottom, the outer wall of the drain pipe 400 abuts against the inner wall of the first water stop ring 401 and the second water stop ring 402, and then the second water stop ring 402 and the outer wall of the drain pipe 400 are welded and fixed.

[0055] Through the above structure, the SBS waterproof coiled material has good water resistance, forms a continuous waterproof film through hot melting and pasting, and blocks the penetration of underground water; the fine stone concrete has high hardness and can resist mechanical impact and sharp object scratching during construction, thereby protecting the waterproof layer 700; and the water stop ring is based on the "water stop sealing principle", the fixed connection of the water stop ring and the cushion layer 600 and the protection layer 800 forms an annular sealing band, increases the path length of the underground water penetrating along the outer wall of the pipe, and realizes the water stop effect.

[0056] It should be noted that, with reference to Figure 1 , the waterproof layer 700 wraps the outer wall of the drain pipe 400, and the waterproof layer 700 extends to abut against the second water stop ring 402.

[0057] In some embodiments, with reference to Figure 1 , the filter layer 320 is formed by mixing gravel and sand. The gravel forms large pores, which facilitates the rapid penetration of underground water and intercepts large particles of silt; and the sand fills the gaps between the gravel and intercepts small impurities to prevent them from entering the filter bucket 300.

[0058] In some embodiments, with reference to Figure 1The part of the drain pipe 400 built in the filter barrel 300 is provided with a plurality of water permeable holes 403, the plurality of water permeable holes 403 are distributed in the pipe wall of the drain pipe 400 in a matrix, and the water permeable holes 403 are covered with non-woven fabric. The matrix-distributed water permeable holes 403 increase the water inlet area of the drain pipe 400 and improve the water pumping efficiency; the non-woven fabric intercepts small impurities (such as silt particles) in water to prevent them from entering the drain pipe 400 and blocking the pipeline; the non-woven fabric has water permeability and does not affect the underground water entering the drain pipe 400.

[0059] In some embodiments, with reference to Figure 1 The combined filter 420 includes a filter screen 421, a filter sponge 422, and a limiting screen 423, which are arranged in layers from top to bottom. In actual use, the upper filter screen 421 intercepts large-particle impurities (such as small stones) to prevent them from damaging the filter sponge 422; the middle filter sponge 422 intercepts small impurities (such as silt particles) to improve the filtering precision; and the lower limiting screen 423 fixes the position of the filter sponge 422 to prevent the sponge from being sucked into the drain pipe 400 during water pumping, while allowing the filtered water to enter the pipe. The three-layer structure realizes multi-stage filtering and greatly reduces the risk of drain pipe 400 blockage.

[0060] In some embodiments, with reference to Figure 1 The water pumping mechanism 410 includes a water pump 411 and a hose 412, both ends of the hose 412 are fixedly connected with the water pump 411 and the upper end of the drain pipe 400, respectively, and the filter barrel 300 is built in a water level sensor, which is electrically connected with the pump and controls the output power of the pump. The water level sensor converts the liquid level signal into an electrical signal and transmits it to the pump control system; the control system adjusts the voltage / current of the pump according to the signal, thereby changing the output power, to realize the linkage adjustment of "water level-power".

[0061] The embodiments of the application are described in detail above in combination with the drawings, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A deep foundation pit dewatering structure for use in near-water zones, characterized in that, include: A retaining wall (100) is provided extending along the perimeter of the deep foundation pit. The retaining wall (100) is in the form of a closed ring and encloses the deep foundation pit. The depth to which the retaining wall (100) is inserted into the foundation is greater than the depth of the deep foundation pit. A rainwater well (200) is located inside the retaining wall (100). Multiple rainwater wells (200) are provided and are arranged at intervals along the extension direction of the retaining wall (100). A filter bucket (300) corresponds one-to-one with a rainwater well (200). The filter bucket (300) is inserted into the rainwater well (200). The filter bucket (300) has filter holes (310) on its wall. A filter layer (320) is provided between the filter bucket (300) and the well wall of the rainwater well (200). A drain pipe (400) is embedded in the filter barrel (300). The drain pipe (400) and the filter barrel (300) are detachably connected. A water pumping mechanism (410) is detachably connected to the top of the drain pipe (400). The lower end of the drain pipe (400) extends into the bottom of the filter barrel (300). A combined filter element (420) is provided at the lower end of the drain pipe (400).

2. The deep foundation pit dewatering structure for near-water zones according to claim 1, characterized in that, The lower part of the retaining wall (100) is connected to a jet grouting pile (500), the jet grouting pile (500) is continuously arranged along the extension direction of the retaining wall (100), the top of the jet grouting pile (500) is provided with a groove (510), and the lower end of the retaining wall (100) is provided with a protrusion (110), the protrusion (110) is embedded in the groove (510).

3. The deep foundation pit dewatering structure for near-water zones according to claim 1, characterized in that, The width of the groove (510) is 1 / 2 to 1 / 3 of the width of the jet grouting pile (500).

4. The deep foundation pit dewatering structure for near-water zones according to claim 1, characterized in that, Also includes: A cushion layer (600) is provided to cover the surface of the bottom of the deep foundation pit; the cushion layer (600) is made of concrete. A waterproof layer (700) is provided, covering the surface of the padding layer (600), the waterproof layer (700) being made of SBS waterproof membrane; A protective base layer (800) covers the surface of the waterproof layer (700), the protective base layer (800) being made of fine aggregate concrete; The drain pipe (400) is provided with a first water-stop ring (401) and a second water-stop ring (402) on its body. The first water-stop ring (401) is fixedly connected to the pad layer (600) and covers the dewatering well (200). The second water-stop ring (402) is fixedly connected to the protective bottom layer (800) and is located above the first water-stop ring (401).

5. The deep foundation pit dewatering structure for near-water zones according to claim 4, characterized in that, The waterproof layer (700) wraps around the outer wall of the drain pipe (400) and extends to abut against the second water-stop ring (402).

6. The deep foundation pit dewatering structure for near-water zones according to claim 1, 4, or 5, characterized in that, The filter layer (320) is composed of a mixture of gravel and sand.

7. The deep foundation pit dewatering structure for near-water zones according to claim 6, characterized in that, The portion of the drain pipe (400) built into the filter bucket (300) is provided with a plurality of water-permeable holes (403), which are arranged in a matrix on the pipe wall of the drain pipe (400) and are covered with non-woven fabric.

8. The deep foundation pit dewatering structure for near-water zones according to claim 6, characterized in that, The combined filter element (420) includes a filter screen (421), a filter sponge (422), and a limiting net (423), which are stacked from top to bottom.

9. The deep foundation pit dewatering structure for near-water zones according to claim 1, characterized in that, The pumping mechanism (410) includes a pump (411) and a hose (412). The two ends of the hose (412) are fixedly connected to the pump (411) and the upper end of the drain pipe (400), respectively. The filter tank (300) has a built-in water level sensor. The water level sensor is electrically connected to the pump and controls the output power of the pump.

10. A construction method, characterized in that, For constructing the deep foundation pit dewatering structure according to any one of claims 1 to 9, the following steps are included: Step 1, Construction of retaining wall (100): First, measure and lay out the perimeter of the deep foundation pit to determine the construction boundary of the retaining wall (100); construct the retaining wall (100) along the boundary using steel sheet piles, concrete continuous walls and other techniques to ensure that the retaining wall (100) forms a closed ring around the deep foundation pit, and control the depth of the retaining wall (100) inserted into the foundation to be greater than the depth of the deep foundation pit; after construction, check the sealing and verticality of the retaining wall (100) to avoid gaps or tilting. Step 2, Construction of dewatering wells (200): In the inner area of ​​the retaining wall (100), mark multiple dewatering well (200) points according to the preset interval distance, ensuring that the points are evenly distributed along the extension direction of the retaining wall (100); use drilling machinery to drill holes at the marked points, the drilling depth must meet the groundwater extraction requirements, and clean the soil inside the hole after drilling to form a dewatering well (200); Step 3: Install the filter bucket (300) and fill the filter layer (320): Prepare a filter bucket (300) that matches the specifications of the rainwater well (200). Insert the filter bucket (300) into each rainwater well (200) one by one. Adjust the position of the filter bucket (300) so that a uniform gap is formed between the bucket wall and the well wall (200). Fill the gap with the filter layer (320) in layers. After each layer is filled, press it lightly to make it compact, so that the filter layer (320) is fully filled and the filter holes (310) are not blocked. Step 4: Install the drain pipe (400): Install the combined filter element (420) at the lower end of the drain pipe (400), and then insert the drain pipe (400) into the filter barrel (300) so that the lower end of the drain pipe (400) extends into the bottom of the filter barrel (300). Step 5, Connect and debug the pumping mechanism (410): Connect the pumping mechanism (410) to the top of the drainage pipe (400) via a detachable connection; after checking the sealing of each component connection, start the pumping mechanism (410) for trial operation, observe whether the groundwater enters the drainage pipe (400) and is pumped out in sequence through the filter layer (320), the filter bucket (300) filter holes (310), and the combined filter element (420), while monitoring the water level drop in the deep foundation pit to ensure that the construction effect meets the requirements.

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