Front support grouting steel pipe bottom plate water stop structure

Abstract

The utility model provides a front bracing grouting steel pipe bottom plate water stop structure which comprises a front bracing steel pipe, the two ends of the front bracing steel pipe are an injection end and a supporting end respectively, the injection end is supported at the top of a fender post, the supporting end is supported below the bottom of a foundation pit before excavation, and the bottom of the foundation pit after excavation is suitable for pouring and forming a bottom plate. The front supporting steel pipe comprises a cutting part and a retaining part which sequentially extend between the injection end and the supporting end. According to the front support grouting steel pipe bottom plate water stop structure, the inner water stop piece is connected to the radial inner side of the front support steel pipe in a sealed mode and further matched with the clay ball filled in the inner side, located below the bottom of a foundation pit, of the front support steel pipe so that an upper reverse seepage channel in the pipe can be cut off, and water leakage of the inner side of the front support steel pipe is avoided; meanwhile, the radial outer side of the water stop area, corresponding to the bottom plate, of the front supporting steel pipe is provided with a plurality of outer water stop pieces arranged at intervals in the length direction of the front supporting steel pipe to cut off upward reverse seepage of the outer wall of the pipe, and water leakage of the outer side wall of the front supporting steel pipe is avoided.

Description

Technical Field

[0001] This utility model relates to the field of foundation pit engineering technology, and in particular to a water-stopping structure for a front-supported grouting steel pipe bottom plate. Background Technology

[0002] The pre-supported grouting steel pipe foundation pit retaining method has been widely used in foundation pit engineering. After the foundation pit excavation and basement construction are completed, and the pre-supported grouting steel pipe is removed, the water-stopping of the steel pipe in the bottom slab area becomes particularly important. For example, patent application CN114737618A discloses a construction method for water-stopping the pre-supported grouting steel pipe, proposing a waterproof structure by setting a water-stopping steel plate around the steel pipe in the water-facing area of ​​the basement bottom slab to prevent water seepage around the steel pipe. Chinese utility model patent CN220789866U discloses a water-stopping structure for the pre-supported grouting steel pipe passing through the bottom slab, proposing a waterproof structure by setting a water-stopping steel plate around the steel pipe in the water-facing area of ​​the basement bottom slab, setting another water-stopping steel plate inside, and filling it with concrete to prevent water seepage around and inside the steel pipe.

[0003] However, the existing front-supported grouting steel pipe waterstop has the following problems:

[0004] A water-stop steel plate is installed around the steel pipe. However, due to welding defects between the water-stop steel plate and the outside of the steel pipe, water leakage still occurs on the outer side wall of the steel pipe. In addition, the filling and grouting of the steel pipe are not dense, forming a seepage channel inside the pipe. The water-stop steel plate installed inside cannot completely stop the water, and internal leakage often occurs.

[0005] To address the aforementioned problems, this utility model proposes a front-support grouting steel pipe bottom plate water-stop structure that can prevent water leakage on the inner and outer sides of the steel pipe. Utility Model Content

[0006] To address the problems existing in the current front-supported grouting steel pipe water-stop structure, this utility model provides a front-supported grouting steel pipe bottom plate water-stop structure.

[0007] According to one objective of this utility model, this utility model provides a front-supported grouting steel pipe bottom plate water-stop structure, including a front-supported steel pipe, the two ends of which are an injection end and a support end, respectively. The injection end is supported on the top of the retaining pile, and the support end is supported below the bottom of the foundation pit before excavation. The bottom of the foundation pit after excavation is suitable for casting a bottom plate. The front-supported steel pipe includes a cut-off part and a retained part extending sequentially between the injection end and the support end. The cut-off part is located above the surface of the formed bottom plate, and the retained part is located below the surface of the formed bottom plate. The retained part is sequentially filled with first crushed stone, clay and second crushed stone in a manner away from the support end. The cut-off part is filled with second crushed stone. Both the first crushed stone and the second crushed stone are compacted by grouting.

[0008] The reserved portion of the front support steel pipe is provided with a water-stopping area corresponding to the bottom plate. The water-stopping area is provided with a number of external water-stopping components arranged sequentially from top to bottom along the length direction of the front support steel pipe. The external water-stopping components are located on the radial outer side of the front support steel pipe and are arranged along the circumference of the front support steel pipe. The external water-stopping components are provided with casting holes. The radial inner side of the reserved portion is sealed with an internal water-stopping component, which corresponds to the arrangement of the second crushed stone.

[0009] Preferably, both the first and second crushed stones are graded crushed stones, and the clay is spherical clay.

[0010] Preferably, the outer waterstop is annular, and there are two outer waterstops, namely an upper outer waterstop and a lower outer waterstop. The upper outer waterstop and the lower outer waterstop are arranged from top to bottom on the outside of the front support steel pipe, and the radial dimension of the upper outer waterstop is larger than that of the lower outer waterstop.

[0011] Preferably, the outer waterstop is a steel outer waterstop, the inner ring side of the outer waterstop is welded to the radial outer side of the front support steel pipe, and the outer waterstop is divided into two semi-rings in the circumferential direction.

[0012] Preferably, there are multiple casting holes, which are arranged at intervals along the circumference of the outer waterstop.

[0013] Preferably, the diameter of the casting hole is not less than the maximum coarse aggregate particle size of the cast base plate.

[0014] Preferably, the radial outer side of the inner waterstop and the radial inner side of the front support steel pipe are welded together, and a weld is formed between the radial outer side of the inner waterstop and the radial inner side of the front support steel pipe. The waterstop strip is provided on the side of the inner waterstop facing the cut-off part, and the waterstop strip seals and connects the weld.

[0015] Preferably, the inner water-stopping component is an elliptical inner water-stopping component made of plate-shaped steel.

[0016] Preferably, a filling area is reserved between the inner waterstop and the upper end face of the base plate, and the filling area is filled with micro-expansion concrete.

[0017] Preferably, the top of the retaining pile is provided with a ring beam that connects to the injection end of the front support steel pipe.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] The water-stop structure of the grouting steel pipe bottom plate has an inner water-stop component sealed on the radial inner side of the grouting steel pipe. It is further combined with the clay ball filled on the inner side of the grouting steel pipe below the bottom of the foundation pit to isolate the upper reverse seepage channel inside the pipe and prevent water leakage on the inner side of the grouting steel pipe.

[0020] The front support steel pipe corresponds to the water-stopping area of ​​the base plate. Several external water-stopping components are arranged at intervals along the length of the front support steel pipe on its radial outer side. Furthermore, pouring holes are opened on the external water-stopping components. The concrete for pouring the base plate can pass through the pouring holes, which facilitates the concrete pouring below the water-stopping steel plate and between adjacent water-stopping steel plates to ensure compaction. This isolates the upward seepage on the outer wall of the pipe, achieving a better water-stopping effect on the outer wall of the front support steel pipe and preventing water leakage on the outer side of the front support steel pipe.

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

[0022] Figure 1 This is a schematic diagram of one of the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model.

[0023] Figure 2 This is a second schematic diagram of the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model;

[0024] Figure 3 This is a third schematic diagram of the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model;

[0025] Figure 4 This is a fourth schematic diagram illustrating the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model.

[0026] Figure 5 This is a fifth schematic diagram of the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model;

[0027] Figure 6 This is a schematic diagram of the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model.

[0028] Figure 7 This is a schematic diagram of the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model.

[0029] Figure 8 This is a schematic diagram of the construction conditions of the front-supported grouting steel pipe bottom plate water-stop structure described in this utility model.

[0030] Figure 9 This is a cross-sectional schematic diagram of a front-supported grouting steel pipe bottom plate water-stop structure according to the present invention;

[0031] Figure 10This is a top view schematic diagram of a front-supported grouting steel pipe bottom plate water-stop structure according to the present invention;

[0032] Figure 11 This is a schematic diagram of the outer upper waterstop component of the front-supported grouting steel pipe bottom plate waterstop structure described in this utility model;

[0033] Figure 12 This is a schematic diagram of the lower outer waterstop component of the front-supported grouting steel pipe bottom plate waterstop structure described in this utility model;

[0034] Figure 13 for Figure 9 Schematic diagram of the cross section of section aa. Detailed Implementation

[0035] The following description is intended to provide a detailed account of the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0036] Please see Figure 7-13 This utility model provides a technical solution: a front-supported grouting steel pipe bottom plate water-stop structure, comprising:

[0037] A front support steel pipe 100 has an injection end 100a and a support end 100b at its two ends. The injection end 100a is supported on the top of the retaining pile 200, and the support end 100b is supported below the bottom of the foundation pit 300 before excavation. The bottom of the foundation pit 300 after excavation is suitable for casting a base plate 400. The front support steel pipe 100 includes a cut-off part 101 and a retaining part 102 extending sequentially between the injection end 100a and the support end 100b. The cut-off part 101 is located above the surface of the formed base plate 400, and the retaining part 102 is located below the surface of the formed base plate 400.

[0038] The retained portion 102 is sequentially filled with first crushed stone 103, clay 104 and second crushed stone 105 in a manner away from the support end 100b. The cut portion 101 is filled with second crushed stone 105. The front support steel pipe 100 is compacted by grouting. The retained portion 102 of the front support steel pipe 100 is provided with a water-stopping area 106 corresponding to the bottom plate 400. The water-stopping area 106 is provided with a plurality of external water-stopping components 500 arranged sequentially from top to bottom along the length direction of the front support steel pipe 100. The external water-stopping components 500 are located on the radial outer side of the front support steel pipe 100 and are arranged along the circumference of the front support steel pipe 100. The external water-stopping components 500 are provided with casting holes 501.

[0039] The radially inner side of the retention portion 102 is sealed with an inner water-stopping component 600, which is arranged corresponding to the second gravel 105.

[0040] The water-stopping structure of the bottom plate of the grouting steel pipe of the front support has an inner water-stopping component 600 sealed on the radial inner side of the front support steel pipe 100. It is further combined with the clay ball 104 filled on the inner side of the front support steel pipe 100 below the bottom of the foundation pit to isolate the upper reverse seepage channel in the pipe and prevent water leakage on the inner side of the front support steel pipe 100.

[0041] Several external waterstops 500 are arranged at intervals along the length of the front support steel pipe 100 on the radial outer side. Furthermore, a pouring hole 501 is opened on the external waterstop 500. The concrete for pouring the base plate 400 can pass through the pouring hole 501, which facilitates the concrete pouring below the waterstop steel plate and between adjacent waterstop steel plates to achieve a better water-stopping effect on the outer wall of the front support steel pipe 100 and prevent water leakage on the outer side of the front support steel pipe 100.

[0042] Furthermore, both the first crushed stone 103 and the second crushed stone 105 are graded crushed stones, and the clay 104 is spherical clay 104.

[0043] The outer waterstop 500 is annular, and there are two outer waterstops 500, namely an upper outer waterstop 502 and a lower outer waterstop 503. The upper outer waterstop 502 and the lower outer waterstop 503 are arranged sequentially from top to bottom on the outer side of the front support steel pipe 100. Further, see Figure 10 The radial dimension of the upper outer waterstop 502 is larger than the radial dimension of the lower outer waterstop 503. In one embodiment, the outer waterstop 500 is a steel outer waterstop 500, and the inner ring side of the outer waterstop 500 is welded to the radial outer side of the front support steel pipe 100.

[0044] Further, see Figure 11 and 12 The external water stop 500 is divided into several fan rings in the circumferential direction, and further, the external water stop 500 is divided into two half rings in the circumferential direction.

[0045] Furthermore, there are multiple casting holes 501, which are arranged at intervals along the circumference of the outer waterstop 500. Preferably, the casting holes 501 are arranged at equal intervals along the circumference of the outer waterstop 500.

[0046] Furthermore, the diameter of the casting hole 501 is not less than the maximum coarse aggregate particle size of the base plate 400 being cast.

[0047] The internal water-stop component 600 is a plate-shaped steel internal water-stop component 600, see [link / reference]. Figure 9 and 13 A waterstop strip 601 is provided between the inner waterstop 600 and the radially inner side of the front support steel pipe 100. Furthermore, the inner waterstop 600 is an elliptical inner waterstop 600, with its radially outer side welded to the radially inner side of the front support steel pipe 100, forming a weld between them. The waterstop strip 601 is provided on the side of the inner waterstop 600 facing the cut-off portion 101, and the waterstop strip 601 seals the weld.

[0048] Further, see Figure 9 A filling area is reserved between the inner waterstop 600 and the upper end face of the base plate 400, and the filling area is filled with micro-expansion concrete 107.

[0049] Furthermore, a ring beam 201 is provided at the top of the retaining pile 200 to connect to the injection end 100a of the front support steel pipe 100.

[0050] The construction process for the front-supported grouting steel pipe base plate waterstop structure is as follows:

[0051] S1. See also Figure 1 200 retaining piles were constructed, and 100 steel pipes for front support were driven in.

[0052] S2. See also Figure 2 Install 108 grouting pipes;

[0053] S3. See also Figure 3 Fill the first crushed stone 103 at the bottom of the front support steel pipe 100;

[0054] S4. See also Figure 4 Below the bottom of the foundation pit, the bare section of the 100mm steel pipe supporting the foundation is filled with spherical clay 104.

[0055] S5. See also Figure 5 The second crushed stone 105 on the upper part of the front support steel pipe 100 is filled to the injection end 100a;

[0056] S6. See also Figure 6 The front support steel pipe is 100mm thick and grouted, and the construction ring beam is 201mm thick.

[0057] S7. See also Figure 7 Excavate the foundation pit to the bottom;

[0058] S8. See also Figure 8 The upper and lower waterstops 502 and the lower waterstop 503 are installed outside the base plate 400 area, and the base plate 400 is cut off. The cut-off part 101 of the front support steel pipe 100 is also cut off.

[0059] The water-stopping structure for the 400 area of ​​the base plate in step S8 is as follows:

[0060] 1. Two circular outer waterstops 500 are installed around the area of ​​the base plate 400 of the front support steel pipe 100. An elliptical steel inner waterstop 600 is installed inside the front support steel pipe 100. The inner waterstop 600 is welded to the front support steel pipe 100. A waterstop strip 601 is installed above the inner waterstop 600 to seal the weld between the inner waterstop 600 and the front support steel pipe 100. Micro-expansion concrete 107 is used to fill the area between the waterstop and the upper surface of the base plate 400.

[0061] 2. Two annular outer upper waterstops 502 and outer lower waterstops 503. The radial dimension of the outer upper waterstop 502 is larger than that of the outer lower waterstop 503. The outer waterstops 500 are all composed of symmetrical semi-circles. A casting hole 501 is opened around one ring of the outer waterstop 500. The diameter of the casting hole 501 is larger than the maximum coarse aggregate particle size of the casting base plate 400. The outer waterstops 500 are welded to the front support steel.

[0062] In summary, the water-stopping structure of the front-supported grouting steel pipe bottom plate has a section of clay ball 104 filled in the bare pipe section below the bottom of the foundation pit of the front-supported steel pipe 100, which isolates the upper reverse seepage channel inside the pipe and reduces the occurrence of water leakage inside the steel pipe from the source. A water-stop strip 601 is installed on the water-stopping component 600 inside the front-supported steel pipe 100 and on the weld seam around the inside of the front-supported steel pipe 100 to prevent water leakage due to weld quality defects.

[0063] Two circular outer waterstops 500 are installed around the front support steel pipe 100. The two outer waterstops 500 form a double waterstop around the front support steel pipe 100. In addition, a pouring hole 501 is opened around the outer waterstop 500 to facilitate the concrete pouring under the outer waterstop 500 and between the two outer waterstops 500, so as to achieve a better waterstop effect.

[0064] The embodiments described above are only used to illustrate the technical ideas and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. The scope of patent application of this utility model should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in this utility model still fall within the patent scope of this utility model.

Claims

1. A front support grouting steel pipe bottom plate water stop structure, comprising a front support steel pipe (100), the two ends of the front support steel pipe (100) are respectively an injection end (100a) and a support end (100b), the injection end (100a) is supported on the top of a retaining pile (200), and the support end (100b) is supported below a foundation pit bottom (300) before excavation, and a formed bottom plate (400) is suitable for being poured and formed after excavation, the front support steel pipe (100) comprises a cut-off part (101) and a retained part (102) extending between the injection end (100a) and the support end (100b) in sequence, wherein the cut-off part (101) is located above the surface of the formed bottom plate (400), and the retained part (102) is located below the surface of the formed bottom plate (400), and the front support steel pipe (100) is filled by grouting. The retained part (102) is filled with first gravel (103), clay (104) and second gravel (105) in sequence away from the support end (100b), the cut-off part (101) is filled with second gravel (105), and the front support steel pipe (100) is compacted by grouting. The retained part (102) of the front support steel pipe (100) is provided with a water stop area (106) corresponding to the bottom plate (400), the water stop area (106) is provided with a plurality of outer water stop pieces (500) arranged in sequence from top to bottom along the length direction of the front support steel pipe (100), the outer water stop pieces (500) are located on the radial outer side of the front support steel pipe (100) and are arranged along the circumferential direction of the front support steel pipe (100), the outer water stop pieces (500) are provided with pouring holes (501), and the radial inner side of the retained part (102) is sealingly connected with an inner water stop piece (600), and the inner water stop piece (600) is arranged corresponding to the second gravel (105).

2. A front support grouting steel pipe bottom plate waterstop structure according to claim 1, characterized in that, The first gravel (103) and the second gravel (105) are both graded gravel, and the clay (104) is spherical clay.

3. A front support grouting steel pipe bottom plate waterstop structure according to claim 1, characterized in that, The outer water stop piece (500) is annular, the number of the outer water stop piece (500) is two, which are an outer upper water stop piece (502) and an outer lower water stop piece (503), the outer upper water stop piece (502) and the outer lower water stop piece (503) are arranged in sequence from top to bottom on the outer side of the front support steel pipe (100), and the radial dimension of the outer upper water stop piece (502) is greater than that of the outer lower water stop piece (503).

4. A front support grouting steel pipe bottom plate waterstop structure according to claim 3, characterized in that, The outer water stop piece (500) is a steel outer water stop piece, the inner ring side of the outer water stop piece (500) is welded with the radial outer side of the front support steel pipe (100), and the outer water stop piece (500) is divided into two half rings in the circumferential direction.

5. A front support grouting steel pipe bottom plate waterstop structure according to claim 1, characterized in that, The number of the pouring holes (501) is a plurality, and the pouring holes (501) are arranged in intervals along the circumferential direction of the outer water stop piece (500).

6. A front support grouting steel pipe bottom plate waterstop structure according to claim 1, characterized in that, The hole diameter of the pouring hole (501) is not less than the maximum coarse aggregate particle size of the poured and formed bottom plate (400).

7. A front support grouting steel pipe bottom plate waterstop structure according to claim 1, characterized in that, The radially outer side of the inner water stop (600) and the radially inner side of the front support steel pipe (100) are welded, a weld joint is formed between the radially outer side of the inner water stop (600) and the radially inner side of the front support steel pipe (100), and a water stop strip (601) is arranged on the side of the inner water stop (600) facing the cutting part (101), which seals the weld joint.

8. A front support grouting steel pipe bottom plate waterstop structure according to claim 7, characterized in that, The inner water stop (600) is an elliptical plate-shaped steel water stop.

9. A front support grouting steel pipe bottom plate waterstop structure according to claim 1, characterized in that, A filling area is reserved between the inner water stop (600) and the upper end surface of the bottom plate (400), and micro-expansive concrete (107) is filled in the filling area.

10. A front support grouting steel pipe bottom plate waterstop structure according to claim 1, characterized in that, A ring beam (201) is arranged at the top of the enclosure pile (200) and connected to the injection end (100a) of the front support steel pipe (100).

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