Bored pile deep foundation pit supporting structure and construction method thereof

Abstract

The application discloses a bored pile deep foundation pit supporting structure and a construction method thereof, and relates to the deep foundation pit supporting field. The bored pile deep foundation pit supporting structure comprises a foundation pit to-be-excavated area surrounded by a plurality of bored piles. A buffer layer is arranged on the periphery of the bored piles, which is used for reducing the extrusion force generated during the construction of the bored piles. A plurality of support piles are arranged between the buffer layer and the bored piles, which are distributed along the circumferential direction of the center of the bored piles and are used for supporting the buffer layer. Elastic cloth is arranged between the buffer layer and the plurality of bored piles, and the plurality of support piles are arranged in the elastic cloth. The elastic cloth is wrapped on the outer surface of the bored piles and is used for transmitting the extrusion force of the bored piles to the buffer layer. A cross beam is arranged on the top of the plurality of bored piles. A waterproof curtain pile is arranged on the periphery of the bored piles. Through the above technical scheme, the extrusion force generated during the pouring of the concrete can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of deep foundation pit support, and in particular to a bored pile deep foundation pit support structure and a construction method thereof. BACKGROUND

[0002] A bored pile is a foundation engineering technology, which is usually used to create a deep and solid foundation support in soil and is often used in structures such as buildings and bridges. A bored pile needs to dig a hole in the ground, and then pour concrete into the hole to form a solid pile or column. The bored pile can have various diameters and depths to adapt to different engineering needs, and is usually used to enhance the bearing capacity of the soil to provide a stable foundation support to prevent buildings from sinking or tilting. Deep foundation pit is an engineering technology for creating a deep underground excavation structure (such as an underground parking lot, basement, underground passage, etc.). When excavating a deep foundation pit, the surrounding soil and geological conditions usually require special support measures to prevent the collapse of the excavation project or soil seepage, including support frames, concrete support walls, bored piles, etc.

[0003] For some construction areas around or near the construction area, natural gas pipelines may be buried. In general, construction will be avoided around natural gas pipelines. However, in some cities where land resources are scarce, construction often needs to continue. The process of concrete bored pile construction will generate extrusion force on the surrounding soil, especially in the area around the bored pile. In the prior art, in order to avoid damaging the natural gas pipeline, additional measures are usually taken around the pipeline, such as strengthening the pipeline support structure or improving the soil, to reduce the impact of extrusion force. However, strengthening the support structure of the pipeline or improving the soil is usually very troublesome, has a long cycle, and has poor protection effect. SUMMARY

[0004] The present application aims to provide a bored pile deep foundation pit support structure and a construction method thereof to solve the technical problem that the process of concrete bored pile construction will generate a large extrusion force on the surrounding soil.

[0005] First aspect

[0006] The present application provides a bored pile deep foundation pit support structure, which comprises:

[0007] A plurality of bored piles, the plurality of bored piles enclose a foundation pit to be excavated area, a buffer layer is provided outside the bored piles, the buffer layer is used to reduce the extrusion force of the bored pile construction, a plurality of support piles are provided between the buffer layer and the bored piles, the plurality of support piles are distributed in a circumferential array along the center of the bored piles, and the support piles are used to support the buffer layer.

[0008] Elastic cloth, located between the buffer layer and a plurality of the bored piles, a plurality of the support piles are located in the elastic cloth, the elastic cloth is wrapped outside the bored piles, and the elastic cloth is used to transfer the extrusion force of the bored piles to the buffer layer;

[0009] Crossbeam, arranged at the top of a plurality of the bored piles;

[0010] Water-stop curtain pile, arranged around the periphery of the bored piles.

[0011] By adopting the above technical scheme, the buffer layer is arranged around a plurality of the bored piles, and the buffer layer reduces the extrusion force of the concrete on the surrounding soil during construction. A plurality of support piles are arranged in the buffer layer, and the support piles are distributed in the circumferential direction along the center of the bored piles, which are used to effectively support and stabilize the buffer layer. The elastic cloth is wrapped outside the bored piles, which is used to transfer the extrusion force of the bored piles to the buffer layer, so as to further reduce the extrusion effect on the surrounding soil. In addition, in order to ensure the sealing and stability of the foundation pit, the water-stop curtain pile is arranged around the bored piles. In summary, by arranging the buffer layer and the elastic cloth, the extrusion force of the concrete pouring is effectively reduced during the construction of the bored piles.

[0012] Optionally, the elastic cloth is provided with a plurality of accommodating cavities, the accommodating cavities are used to accommodate the support piles, the inner wall of the elastic cloth is in abutment with the support piles, and the side of the elastic cloth away from the ground plane is fixedly connected with a mounting block.

[0013] By adopting the above technical scheme, the gravity of the mounting block is greater than that of the elastic cloth, and the mounting block and the elastic cloth are placed into the drilled hole by using the gravity of the mounting block itself, thereby achieving the technical effect of facilitating construction.

[0014] Optionally, the support pile comprises:

[0015] Support pipe, which is connected with the mounting block, and can be inserted into the accommodating cavity;

[0016] Pile body, which is arranged in the lumen of the support pipe, and is fixedly connected with the support pipe.

[0017] By adopting the above technical scheme, the support pipe can be inserted into the accommodating cavity, the pile body is stably fixed in the support pipe, and the gravity of the mounting block helps to place the support system into the drilled hole, so that the construction process is more convenient. The support pipe provides a support structure, which ensures that the elastic cloth and the buffer layer remain stable when bearing the extrusion force, and helps to maintain the stability of the foundation pit. By adopting the above scheme, the stability of the support pile is further enhanced, thereby achieving the purpose of enhancing the buffering effect of the elastic cloth and the buffer layer.

[0018] Optionally, further comprising:

[0019] A ring-shaped positioning plate is detachably connected with the support pile, and the ring-shaped positioning plate is provided with a plurality of installation notches which are matched with the outer surface of the installation block.

[0020] By adopting the above technical scheme, the ring-shaped positioning plate is detachably connected with the support pile, and the ring-shaped positioning plate can be easily separated from the support pile when needed, which helps to conveniently position and assemble the elastic cloth and the support pipe. After the installation and positioning of the elastic cloth and the support pipe are completed, the ring-shaped positioning plate is disassembled and removed, and the positioning of the next elastic cloth and support pipe is performed, thereby reducing the installation time cost and material cost. The plurality of installation notches on the ring-shaped positioning plate are matched with the outer surface of the installation block, so that the elastic cloth can be conveniently formed into a ring shape. The elastic cloth can be tightly wrapped around the support pile and effectively transmit and disperse the extrusion force.

[0021] Optionally, a plurality of installation grooves are formed on the side of the ring-shaped positioning plate close to the bored pile, and electromagnets are installed in the installation grooves.

[0022] The installation block is fixedly connected with a magnetic member on the side away from the bored pile, and the magnetic member is magnetically connected with the electromagnets.

[0023] By adopting the above technical scheme, electromagnets are arranged in the installation grooves, and magnetic members are arranged on the installation blocks. The magnetic connection between the electromagnets and the magnetic members enables the installation blocks to be magnetically attracted and matched with the installation notches of the ring-shaped positioning plate, so that the installation blocks can be quickly positioned in the installation notches of the ring-shaped positioning plate. Then, the support pipe and the installation block are engaged and matched through the protrusions and the grooves, thereby achieving the effect of facilitating the installation and positioning of the elastic cloth and the support pipe.

[0024] Optionally, the water-stop curtain pile comprises:

[0025] A cement-based waterproof layer is arranged on the side of the water-stop curtain pile away from the bored pile.

[0026] A water-stop pile is fixedly connected with the cement-based waterproof layer.

[0027] By adopting the above technical scheme, the cement-based waterproof layer is arranged on the side of the water-stop curtain pile away from the bored pile, thereby providing an effective waterproof barrier for preventing groundwater or water in the soil from penetrating into the foundation pit, thereby maintaining the dry state of the foundation pit, which is crucial for the stability of the deep foundation pit support structure and the protection of the surrounding soil. In addition, the water-stop pile is fixedly connected with the cement-based waterproof layer, thereby enhancing the stability of the water-stop curtain pile.

[0028] Optionally, the buffer layer is filled with medium sand.

[0029] By adopting the technical scheme, the medium sand has moderate particle size and distribution, which enables the medium sand to effectively disperse the extrusion force applied thereon during the filling process. The uniformity of the medium sand particles helps to uniformly transmit the extrusion force to the surrounding soil, reducing the generation of local extrusion force. This helps to maintain the stability of the soil around the foundation pit and reduces the risk of soil subsidence caused by extrusion. In addition, the medium sand in the buffer layer can reduce the impact of the extrusion force on the support structure. During construction, the extrusion force is usually caused by concrete filling, and the use of medium sand as a buffer layer can effectively buffer such impact and reduce the bearing pressure on the support structure. By adopting the above scheme, the effect of reducing the extrusion force on the nearby natural gas pipeline is achieved.

[0030] Optionally, it further comprises:

[0031] The prestressed anchor cable is fixedly connected with the bored pile.

[0032] By adopting the technical scheme, the prestressed anchor cable can effectively increase the stability and bearing capacity of the support structure. By providing additional tension to resist external load and extrusion force, the risk of displacement or deformation of the support structure is reduced. In addition, during the deep foundation pit support process, the prestressed anchor cable can effectively resist the horizontal and vertical pressure of the soil to prevent the deep foundation pit from collapsing.

[0033] The second aspect

[0034] The application provides a bored pile deep foundation pit support construction method, which utilizes the construction of the above-mentioned bored pile deep foundation pit support structure, and comprises the following steps:

[0035] S1, construction of a waterproof curtain pile;

[0036] S2, construction of a bored pile;

[0037] S3, gradually constructing excavation in the foundation pit area to be excavated, and providing a prestressed anchor cable fixedly connected with the bored support pile;

[0038] S4, building a cross beam on the top of the bored pile.

[0039] By adopting the technical scheme, a variety of support structures are combined, including a waterproof curtain pile, a bored pile, a prestressed anchor cable, and a cross beam. The stability of the foundation pit and the safety of the structure can be effectively maintained, and different types of soil conditions can be dealt with. In addition, by gradually constructing excavation in the foundation pit area to be excavated and providing a prestressed anchor cable connected with the bored pile, the prestressed anchor cable can resist extrusion force and reduce the extrusion impact on the soil layer.

[0040] Optionally, the S2 further comprises:

[0041] S21: drilling a hole with a radius equal to the radius of the bored pile and the thickness of the buffer layer;

[0042] S22, providing a ring-shaped positioning plate, a support pipe and a mounting block, placing the ring-shaped positioning plate at the bottom of the hole, inserting the support pipe into the elastic cloth and clamping the mounting block, placing the elastic cloth and the mounting block into the hole so that the mounting block abuts against the ring-shaped positioning plate;

[0043] S23, pouring concrete into the support pipe;

[0044] S24, pouring a buffer layer between the elastic cloth and the inner wall of the hole;

[0045] S25, pouring concrete in the area enclosed by the elastic cloth.

[0046] By adopting the above technical scheme, the extrusion force generated during the concrete pouring construction process is effectively reduced.

[0047] In summary, the present application includes at least one of the following beneficial technical effects:

[0048] 1. By providing a plurality of bored piles, a buffer layer, an elastic cloth, a support pile, a beam and a waterproof curtain pile, the extrusion force generated during the concrete pouring construction process of the bored pile is effectively reduced;

[0049] 2. By providing a ring-shaped positioning plate, the plurality of mounting notches on the ring-shaped positioning plate and the outer surface of the mounting block are adapted to each other, so that the elastic cloth can be easily formed into a ring shape, and the elastic cloth can be tightly wrapped around the support pile to effectively transfer and disperse the extrusion force;

[0050] 3. By providing a prestressed anchor cable, the horizontal and vertical pressure of the soil is effectively resisted, the deep foundation pit is prevented from collapsing, and the extrusion force of the concrete on the soil layer during the construction process is also reduced;

[0051] 4. By providing a bored pile deep foundation pit supporting construction method, the extrusion force of the concrete bored pile construction process on the surrounding soil layer is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 is a schematic view of the overall structure in embodiment 1 of the present application;

[0053] Figure 2 is an enlarged view of A of Figure 1 ;

[0054] Figure 3 is a schematic view of the elastic cloth structure in embodiment 1;

[0055] Figure 4 is an enlarged view of B in Figure 3

[0056] Figure 5 is a structural schematic diagram of the ring-shaped positioning plate in Example 2;

[0057] Figure 6 is a half-section schematic diagram of the ring-shaped positioning plate in Example 2;

[0058] Figure 7 is a top view of the overall structure in Example 2.

[0059] In the figure: 1, cast-in-place pile; 2, buffer layer; 21, support pile; 211, support pipe; 212, pile body; 3, elastic cloth; 31, mounting block; 311, magnetic part; 4, waterproof curtain pile; 41, cement-based waterproof layer; 42, waterproof pile; 5, ring-shaped positioning plate; 51, mounting notch; 52, electromagnet; 6, prestressed anchor cable; 7, rope. DETAILED DESCRIPTION

[0060] The present application is further described in detail below with reference to the accompanying drawings. Figure 1 - the accompanying drawings Figure 7 , which make further detailed description of the present application.

[0061] The first aspect

[0062] Example 1:

[0063] With reference to Figure 1 , a cast-in-place pile deep foundation pit support structure includes: a plurality of cast-in-place piles 1, a buffer layer 2, an elastic cloth 3, a cross beam (not shown in the figure) and a waterproof curtain pile 4.

[0064] With reference to Figure 1 and Figure 2 ​, the multiple bored piles 1 enclose the area to be excavated, and the buffer layer 2 is arranged outside the bored piles 1, which is used to reduce the extrusion force of the concrete during the construction of the bored piles 1. In this embodiment, the buffer layer 2 is filled with medium sand. The medium sand has moderate particle size and distribution, which makes it effective to disperse the extrusion force applied to it during the filling process. The uniformity of the medium sand particles helps to evenly transmit the extrusion force to the surrounding soil, reducing the generation of local extrusion force. It helps to maintain the stability of the soil around the foundation pit, reducing the risk of soil subsidence caused by extrusion. In addition, the medium sand in the buffer layer 2 can reduce the impact of the extrusion force on the support structure. During the construction process, the extrusion force is usually caused by the pouring of concrete. Using medium sand as a buffer layer 2 can effectively buffer this impact, reducing the bearing pressure on the support structure and reducing the extrusion force on the nearby natural gas pipeline. In other embodiments, the buffer layer 2 can use other soft soil or fine sand with the function of absorbing extrusion force.

[0065] With reference to Figure 1 and Figure 2 , the elastic cloth 3 is located between the buffer layer 2 and the multiple bored piles 1, and the elastic cloth 3 is wrapped around the bored piles 1, which is used to transmit the extrusion force of the bored piles 1 to the buffer layer 2. The elastic cloth 3 is wrapped around the outside of the bored piles 1, which is used to transmit the extrusion force of the bored piles 1 to the buffer layer 2, to further reduce the extrusion effect on the surrounding soil. The multiple support piles 21 are arranged between the buffer layer 2 and the bored piles 1, and the multiple support piles 21 are arranged in a circumferential array along the center of the bored piles 1, which is used to support the buffer layer 2. The crossbeam is arranged on the top of the multiple bored piles 1, which further improves the stability of the bored piles 1.

[0066] With reference to Figure 2 and Figure 3 , the buffer layer 2 reduces the extrusion force of the concrete on the surrounding soil layer during the construction process. The support piles 21 are arranged in a circumferential array along the center of the bored piles 1, which is used to effectively support and stabilize the buffer layer 2. The elastic cloth 3 is provided with multiple accommodation cavities, which are used to accommodate the support piles 21. The inner wall of the elastic cloth 3 is in abutment with the support piles 21, and the side (bottom) of the elastic cloth 3 away from the ground is fixedly connected with the mounting block 31. The mounting block 31 has a protrusion, and the gravity of the mounting block 31 is greater than that of the elastic cloth 3. The mounting block 31 itself is used to facilitate the placement of the elastic cloth 3 in the hole with a diameter greater than that of the bored pile, thereby achieving the technical effect of facilitating construction.

[0067] With reference to Figure 1, the waterproof curtain pile 4 is surrounded by the bored pile 1, the waterproof curtain pile 4 includes a cement-based waterproof layer 41 and a waterproof pile 42, the cement-based waterproof layer 41 is arranged on the side of the waterproof curtain pile 4 away from the bored pile 1, and the waterproof pile 42 is fixedly connected with the cement-based waterproof layer 41. By arranging the cement-based waterproof layer 41 on the side of the waterproof curtain pile 4 away from the bored pile 1, an effective waterproof barrier is provided for preventing groundwater or water in the soil from penetrating into the interior of the foundation pit, thereby maintaining the dry state of the foundation pit, which is crucial for the stability of the deep foundation pit support structure and the protection of the surrounding soil. In addition, the waterproof pile 42 is fixedly connected with the cement-based waterproof layer 41, thereby enhancing the stability of the waterproof curtain pile 4.

[0068] With reference to Figure 2 , the support pile 21 includes a support pipe 211 and a pile body 212, the support pipe 211 can be inserted into the accommodating cavity of the elastic cloth 3 and is engaged with the protrusion of the mounting block 31 (combined Figure 4 ), and the support pipe 211 can be inserted into the accommodating cavity. The pile body 212 is arranged in the pipe cavity of the support pipe 211, and the pile body 212 is fixedly connected with the support pipe 211. The support pipe 211 provides a support structure for the buffer layer 2, ensuring that the elastic cloth 3 and the buffer layer 2 remain stable when subjected to extrusion pressure, thereby helping to maintain the stability of the foundation pit. With the above scheme, the stability of the support pile 21 is further enhanced, thereby achieving the purpose of enhancing the buffering effect of the elastic cloth 3 and the buffer layer 2.

[0069] The implementation principle of the embodiment 1 of the present application is as follows:

[0070] By arranging the buffer layer 2 and the elastic cloth 3, the buffering function is effectively achieved. The buffer layer 2 is filled with medium sand, which can reduce the extrusion pressure of the concrete on the surrounding soil during construction and disperse the extrusion pressure applied thereon, thereby reducing the generation of local extrusion pressure, maintaining the stability of the soil around the foundation pit, and reducing the risk of soil subsidence. In addition, the medium sand buffer layer 2 can reduce the impact of extrusion pressure on nearby pipelines. The elastic cloth 3 is located between the buffer layer 2 and the bored pile 1 and is wrapped outside the bored pile 1, playing a role in transmitting extrusion pressure to the buffer layer 2. The elastic cloth 3 can effectively transmit the extrusion pressure of the bored pile 1 to the buffer layer 2, further reducing the extrusion impact on the surrounding soil. Meanwhile, a plurality of support piles 21 are arranged in the buffer layer 2 and are distributed in a circumferential array along the center of the bored pile 1, for supporting and stabilizing the buffer layer 2.

[0071] Embodiment 2

[0072] With reference to Figures 5-7 , which is basically the same as embodiment 1, the difference lies in that a ring-shaped positioning plate 5 and a prestressed anchor cable 6 are additionally arranged.

[0073] With reference to Figure 5 and Figure 6The annular positioning plate 5 is detachably connected with the support pile 21, and the annular positioning plate 5 can be easily separated from the support pile 21 when needed, which helps to conveniently position and assemble the elastic cloth 3 and the support pipe 211. The outer radius of the annular positioning plate 5 is equal to the sum of the thickness of the buffer layer 2 and the radius of the bored pile 1. After the installation and positioning of the elastic cloth 3 and the support pipe 211 are completed, the annular positioning plate 5 is removed, and the positioning of the next elastic cloth 3 and support pipe 211 is performed, which reduces the installation time cost and material cost. The annular positioning plate 5 is provided with a plurality of installation notches 51, and the plurality of installation notches 51 and the outer surface of the mounting block 31 are mutually matched and fitted, so that the elastic cloth 3 can be conveniently formed into a cylindrical shape. It can be ensured that the elastic cloth 3 is tightly wrapped around the support pile 21 and effectively transmits and disperses the extrusion force.

[0074] As a further preferred, the annular positioning plate 5 is provided with a plurality of installation grooves on the side close to the bored pile 1, and an electromagnet 52 is installed in the installation groove. The electromagnet 52 is electrically connected with an external power supply (not shown in the figure) and a switch. The mounting block 31 is fixedly connected with a magnetic member 311 on the side away from the bored pile 1, and the magnetic member 311 is magnetically connected with the electromagnet 52. The installation notches 51 and the outer surface of the mounting block 31 are matched and fitted by manually adjusting the mounting block 31, which is low in efficiency and not accurate enough. Therefore, by the electromagnet 52 and the magnetic member 311 on the mounting block 31, the magnetic connection between the electromagnet 52 and the magnetic member 311 is used to magnetically attract and fit each mounting block 31 and the installation notches 51 of the annular positioning plate 5, so that the mounting block 31 can be quickly and accurately positioned in the installation notches 51 of the annular positioning plate 5.

[0075] Referring to Figure 7 The prestressed anchor cable 6 is fixedly connected with the bored pile 1, and the prestressed anchor cable 6 can effectively increase the stability and bearing capacity of the supporting structure. By providing additional tension to resist external loads and extrusion forces, the risk of displacement or deformation of the supporting structure is reduced. In addition, during the deep foundation pit supporting process, the prestressed anchor cable 6 can effectively resist the horizontal and vertical pressure of the soil to avoid the collapse of the deep foundation pit.

[0076] The implementation principle of the embodiment 2 of the application is as follows:

[0077] The implementation principle is basically the same as that of example 1, except that the annular positioning plate 5 is used to facilitate the rapid installation and positioning of the elastic cloth 3, and the subsequent pouring of the buffer layer 2. The annular positioning plate 5 is suspended by the rope 7 and placed into the hole. Then the switch of the electromagnet 52 is turned on, the elastic cloth 3 with the mounting block 31 is placed into the hole, the electromagnet 52 adsorbs the magnetic part 311 on the mounting block 31, and the automatic positioning of each mounting block 31 is performed, thereby making the elastic cloth 3 automatically form a cylindrical shape, facilitating the subsequent pouring of the buffer layer 2. In addition, the prestressed anchor cable 6 is added to offset the external extrusion force and prevent the deep foundation pit from collapsing.

[0078] Second aspect

[0079] A bored pile deep foundation pit support construction method uses the construction of the above-mentioned bored pile deep foundation pit support structure, including the following steps:

[0080] S1, construction of the waterproof curtain pile 4: determine the position and spacing of the waterproof curtain pile 4, and arrange according to the design requirements. Use appropriate mechanical equipment to drill holes and install the waterproof curtain pile body 212 in the drilled holes. The waterproof pile 42 is a cement mixing pile formed by cement mixing and pouring, and a cement-based waterproof layer 41, such as polyurethane waterproof coating, is poured around the cement mixing pile to effectively prevent groundwater from penetrating.

[0081] S2, construction of the bored pile 1: determine the arrangement position and spacing of the bored pile 1, and set according to the pre-designed structural design requirements.

[0082] Wherein S2 further includes the following steps:

[0083] S21: use appropriate drilling equipment to drill holes until the designed top elevation of the pile is reached. After drilling, perform a first hole cleaning and a second hole cleaning to ensure that the hole is clean. When drilling, the hole radius must be equal to the radius of the bored pile 1 and the thickness of the buffer layer 2.

[0084] S22, provide the annular positioning plate 5, the support pipe 211 and the mounting block 31, place the annular positioning plate 5 at the bottom of the hole, then install the fixed elastic cloth 3 in the drilled hole, insert the support pipe 211 into the elastic cloth 3 and connect the mounting block 31, place the mounting block 31 into the drilled hole in S21 due to its own gravity, so that the mounting block 31 abuts against the annular positioning plate 5, facilitating the subsequent pouring of the buffer layer 2.

[0085] S23, pour concrete into the support pipe 211 to increase the support performance of the support pile 21.

[0086] S24, fill the buffer layer 2 with medium sand or other materials with buffering function between the elastic cloth 3 and the inner wall of the hole. Then fill the steel cage or reinforcing bar in the inner layer. Before pouring the concrete, ensure that the position of the steel cage and the longitudinal reinforcement meet the design requirements.

[0087] S25, pour the concrete in the area enclosed by the elastic cloth 3, and ensure that the concrete is full and has no voids.

[0088] S3, excavate gradually according to the needs of foundation pit construction, ensure the stability of the foundation pit slope during excavation, and take corresponding supporting measures. Set prestressed anchor cable 6 on the foundation pit slope or bottom, connect it with bored pile 1 through fixed anchor rod, provide additional support and stability. Ensure the installation quality of prestressed anchor cable 6 and the control of tension force, tension according to the design requirements and monitor.

[0089] S4, build beam on the top of bored pile 1: according to the design requirements of structure, set beam on the top of bored pile 1, which is used for bearing and transferring load. Install scaffold or other supporting equipment to support and connect the beam on the top of bored pile 1, and ensure its stability and safety. According to the design requirements, carry out the construction of beam, including concrete pouring, maintenance and other procedures, to ensure that the strength and stiffness of the beam meet the design requirements.

[0090] The above are the preferred embodiments of the present application, which do not limit the protection scope of the present application. Therefore, any equivalent changes made on the basis of the structure, shape and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A deep foundation pit support structure for bored cast-in-place piles, characterized in that, include: Multiple bored piles (1) are arranged to form a foundation pit to be excavated. A buffer layer (2) is provided around the bored piles (1). The buffer layer (2) is used to reduce the squeezing pressure during the construction of the bored piles (1). Multiple support piles (21) are provided between the buffer layer (2) and the bored piles (1). The multiple support piles (21) are arranged in a circumferential array along the center of the bored piles (1). The support piles (21) are used to support the buffer layer (2). An elastic cloth (3) is located between the buffer layer (2) and the plurality of bored piles (1), and the plurality of support piles (21) are located inside the elastic cloth (3). The elastic cloth (3) wraps around the bored piles (1), and the elastic cloth (3) is used to transmit the compressive force of the bored piles (1) to the buffer layer (2). A crossbeam is set on the top of the piles of the plurality of the drilled piles (1); Water-stopping curtain piles (4) are arranged around the borehole cast-in-place piles (1); The elastic cloth (3) array has multiple receiving cavities, which are used to receive the support pile (21). The inner wall of the elastic cloth (3) abuts against the support pile (21), and an installation block (31) is fixedly connected to the side of the elastic cloth (3) away from the ground plane.

2. The deep foundation pit support structure for bored cast-in-place piles according to claim 1, characterized in that, The support pile (21) includes: A support tube (211) is snapped into the mounting block (31), and the support tube (211) can be inserted into the receiving cavity; The pile body (212) is disposed inside the cavity of the support pipe (211) and is fixedly connected to the support pipe (211).

3. The deep foundation pit support structure for bored cast-in-place piles according to claim 1, characterized in that, Also includes: The annular positioning plate (5) is detachably connected to the support pile (21). The annular positioning plate (5) has multiple installation notches (51), and the installation notches (51) are fitted to the outer surface of the mounting block (31).

4. The deep foundation pit support structure for bored cast-in-place piles according to claim 3, characterized in that, The annular positioning plate (5) has multiple mounting slots on the side near the bored pile (1), and an electromagnet (52) is installed in the mounting slot; A magnetic component (311) is fixedly connected to the side of the mounting block (31) away from the bored pile (1), and the magnetic component (311) is magnetically connected to the electromagnet (52).

5. A deep foundation pit support structure for bored cast-in-place piles according to claim 1, characterized in that, The water-stop curtain piles (4) include: A cement-based waterproof layer (41) is provided on the side of the water-stop curtain pile (4) away from the bored pile (1); Water-stopping pile (42) is fixedly connected to the cement-based waterproof layer (41).

6. The deep foundation pit support structure for bored cast-in-place piles according to claim 1, characterized in that, The buffer layer (2) is formed by grouting medium sand.

7. The deep foundation pit support structure for bored cast-in-place piles according to claim 1, characterized in that, Also includes: The prestressed anchor cable (6) is fixedly connected to the bored pile (1).

8. A method for constructing deep foundation pit support using bored cast-in-place piles, based on the deep foundation pit support structure using bored cast-in-place piles as described in any one of claims 1-7, characterized in that, Includes the following steps: S1, Construction of water-stop curtain piles (4); S2, Construction of bored piles (1); S3. Gradually excavate the area to be excavated in the foundation pit, and provide prestressed anchor cables (6) to be fixedly connected to the bored piles (1); S4. Construct a crossbeam on the top of the bored pile (1).

9. A method for constructing deep foundation pit support using bored cast-in-place piles according to claim 8, characterized in that, S2 further includes: S21: Drilling, the radius of the hole is equal to the radius of the drilled pile (1) and the thickness of the buffer layer (2); S22. Provide an annular positioning plate (5), a support tube (211), and a mounting block (31). Place the annular positioning plate (5) at the bottom of the hole, insert the support tube (211) into the elastic cloth (3) and engage it with the mounting block (31), and place the elastic cloth (3) and the mounting block (31) into the hole so that the mounting block (31) abuts against the annular positioning plate (5). S23. Pour concrete into the support pipe (211); S24. A buffer layer (2) is injected between the elastic cloth (3) and the inner wall of the hole; S25. Pour concrete into the area enclosed by the elastic cloth (3).

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