A post-installation method for a hanging barrel type anchor structure used to reduce the amount of foundation pit excavation

Abstract

The present invention relates to the field of foundation pit excavation, and discloses a post-installation method of a hanging barrel type anchor structure for reducing the foundation pit excavation volume. By installing a space inside the pile body and setting the anchor inside the pile body, the raised structure formed by the traditional external anchor head is solved, thereby avoiding problems such as the increased foundation pit excavation volume, increased investment, longer construction period, and safety risks of implementing the fat groove caused by the fat groove filling; at the same time, by using the post-installation method, it effectively avoids the close contact between the concrete pouring conduit of the pile body and the hanging barrel type anchor under the extrusion of liquid concrete, resulting in the concrete conduit connection flange being stuck by this device and unable to be pulled out, delaying the concrete pouring, and further avoiding the risk of pile body scrapping; it can also avoid that when pouring the pile body concrete, the flowing concrete will form a large buoyancy on the hanging barrel type anchor buried in the pile body. If it cannot be firmly fixed, it is extremely easy to cause problems such as deviation and floating of the hanging barrel type anchor.

Description

Technical Field

[0001] The present invention relates to the field of foundation pit excavation, and particularly to a method for post-installing a hanging barrel type anchor structure for reducing the foundation pit excavation volume. Background Art

[0002] Foundation pits are used for the foundation construction of building projects or municipal projects. Generally, the larger the structure, the larger the foundation, and the larger the required foundation pit. When the foundation pit support structure adopts the pile + cable anchor support type, it is necessary to first use a drilling tool to drill a hole on the pile body at an angle of 15° - 25°, and then place a cable anchor in the hole for prestress tensioning. To facilitate the tensioning construction of the cable anchor, the anchor is generally located outside the pile body, and a reinforced concrete or steel inclined support (external anchor head) is padded between the anchor and the pile body. The height of the reinforced concrete and the steel inclined support is 400 mm - 600 mm, and numerous protrusions are formed on the side wall of the foundation pit after tensioning. On the other hand, in order to facilitate the pasting of an external waterproof layer on the side wall of the foundation pit, measures such as shotcrete and brick wall masonry are also required to level the aforementioned protrusions.

[0003] The above measures will form a fat groove filling layer with a width of 450 mm - 600 mm between the retaining pile and the outer side wall of the underground main structure. Before excavation, it is necessary to consider in advance including the fat groove filling layer in the excavation volume. For large foundation pits with a perimeter of hundreds of meters, thousands of cubic meters of excavation and a large amount of support costs need to be increased. This not only increases the investment and construction period, but also has a greater risk of high-altitude operation (usually after excavation, a scaffold is erected for operation), and also increases the pollution and damage to the surrounding rock and soil, which is not conducive to environmental protection, green energy conservation and low carbon, and realizing the sustainable development of urban construction. Summary of the Invention

[0004] The present invention aims to provide a method for post-installing a hanging barrel type anchor structure for reducing the foundation pit excavation volume, so as to cancel the fat groove filling layer, reduce the foundation pit excavation, protect the environment, and achieve green energy conservation and low carbon.

[0005] To achieve the above object, the present invention adopts the following technical solution: A method for post-installing a hanging barrel type anchor structure for reducing the foundation pit excavation volume, comprising the following steps:

[0006] Step 1: Prepare a steel reinforcement cage, and additional circular reinforcing stirrups need to be added at the positions where the hanging barrel type anchor needs to be installed; place the steel reinforcement cage into the pile hole and pour pile body concrete;

[0007] Step 2: Excavate the foundation pit. When the foundation pit is excavated to the predetermined position for tensioning the cable anchor, drill an anchor hole on the pile body through a drilling tool, place a cable anchor in the anchor hole, and grout the anchor hole;

[0008] Step 3: Excavate the concrete at the position on the pile body where the hanging barrel-type anchor is to be installed. Then, cut some of the main bars and stirrups of the steel reinforcement cage, and bend the cut main bars and stirrups outward to form an installation space. The hanging barrel-type anchor includes a core barrel. The size of the installation space is adapted to the core barrel. The core barrel is fixedly arranged in the installation space. A pressure-bearing adjustment unit is arranged in the core barrel, and external stiffening ribs are fixed outside the core barrel. After the hanging barrel-type anchor is placed in the installation space and adjusted in place, restore the bent pile body steel bars and weld them to the external stiffening ribs;

[0009] Step 4: The pressure-bearing member is provided with a first receiving hole. The inner diameter of the first receiving hole is smaller than the anchor. The steel cable passes through the first receiving hole and the anchor in sequence, tension the anchor cable, and seal the anchor.

[0010] The beneficial effects of this solution are as follows: In this solution, an installation space is provided inside the pile body, and the anchor is arranged on the inner side of the pile body, thus solving the raised structure formed by the traditional external anchor head, and further avoiding problems such as the increased foundation pit excavation volume, increased investment, longer construction period, and safety risks of implementing the fat groove caused by the fat groove filling;

[0011] This solution adopts a post-installation solution. First, pour the pile body, and then install the hanging barrel-type anchor on the pile body, effectively avoiding the close contact between the concrete pouring conduit of the pile body and the core barrel of this device under the extrusion of the liquid concrete, resulting in the flange of the concrete conduit being stuck and unable to be pulled out, delaying the concrete pouring, and further avoiding the risk of pile body scrapping;

[0012] It can also avoid that when pouring the pile body concrete, the flowing concrete will form a large buoyancy on the hanging barrel-type anchor buried in the pile body. If it cannot be firmly fixed, it is extremely easy to cause problems such as the deviation and floating of the hanging barrel-type anchor.

[0013] Further, the core barrel includes a core barrel body and bolts. The external stiffening ribs are fixedly arranged on the core barrel body. The bolts are annular and fixedly arranged at the free end of the external stiffening ribs. The steel reinforcement cage includes main steel bars. The main steel bars pass through between the core barrel body and the bolts and are fixedly connected to the stiffening ribs.

[0014] Beneficial effects: External stiffening ribs are arranged outside the core barrel body, and bolts are arranged at the free end of the external stiffening ribs.

[0015] Further, the pressure-bearing adjustment unit includes a pressure-bearing member. The pressure-bearing member is provided with a first receiving hole. The pressure-bearing member is fixedly arranged in the core barrel. The pressure-bearing member and the inner wall of the core barrel enclose an anchor installation cavity. The anchor is fixed in the anchor installation cavity. The anchor cable passes through the core barrel and the first receiving hole in sequence and is fixedly connected to the anchor.

[0016] Beneficial effects: When the anchor cable is tensioned, it needs to be inclined at an angle of 15°-25° with the horizontal plane. When installing the core tube, the core tube needs to be fixedly connected to the pile body to provide sufficient support force to meet the tensioning requirements, so as to transfer the tension of the prestressed anchor cable to the pile body, making the force transmission mechanism between the formed anchor head and the pile body consistent with that of the traditional external anchor head, which can ensure the safety of the retaining structure.

[0017] Furthermore, the pressure-bearing adjustment unit further includes an adjustment member. The adjustment member is arranged between the anchor and the pressure-bearing member and is provided with a second accommodation hole for the anchor cable to pass through. The anchor cable sequentially passes through the first accommodation hole and the second accommodation hole and is fixedly connected to the anchor head. The contact surface between the pressure-bearing member and the adjustment member is a convex spherical surface, the contact surface between the adjustment member and the pressure-bearing member is a concave spherical surface that cooperates with the convex spherical surface, and the concave spherical surface is slidably connected to the convex spherical surface. The contact surface between the adjustment member and the anchor is a plane.

[0018] Beneficial effects: When the anchor cable is tensioned, it needs to be inclined at an angle of 15°-25° with the horizontal plane. When installing the core tube, the core tube needs to be fixedly connected to the pile body to provide sufficient support force to meet the tensioning requirements, so as to transfer the tension of the prestressed anchor cable to the pile body, making the force transmission mechanism between the formed anchor head and the pile body consistent with that of the traditional external anchor head, which can ensure the safety of the retaining structure. The installation accuracy requirements for the core tube are relatively high. Through the special design of the contact surfaces of the pressure-bearing member and the adjustment member in this application, when there is a deviation in the installation of the core tube, the adjustment member can slide on the pressure-bearing member, driving the anchor to rotate along the center of the anchor hole, adjusting the incident angle of the anchor cable, achieving the purpose of coordinating construction errors and making the angle of the anchor cable unaffected, reducing the installation requirements for the core tube and improving the construction efficiency.

[0019] Furthermore, the core tube is a conical structure. The conical structure includes a narrow end and a wide end. The narrow end extends into the installation space, and the wide end is fixedly connected to the pile body. The pressure-bearing member is sleeved inside the core tube and fits with the inner wall of the core tube. The angle between the axis of the conical structure and the horizontal plane is 15°-25°.

[0020] Beneficial effects:

[0021] Furthermore, the core tube is a circular cone, and the angle between the side wall of the conical structure and the axis is 15°-25°. The reinforcing member is rotatably arranged inside the core tube.

[0022] Beneficial effects: The core tube is set as a conical structure, and the pressure-bearing member is sleeved inside the core tube, so that there is no need to set additional connection structures between the core tube and the pressure-bearing member to fixedly install the pressure-bearing member inside the core tube, simplifying the installation process and improving the construction efficiency.

[0023] Meanwhile, by presetting the angle between the axis of the core tube and the horizontal plane, the axis of the conical structure is made the same as the cable anchor tensioning angle, which facilitates the transfer of the cable anchor tension to the core tube through the pressure-bearing member, enabling the core tube to help disperse the cable anchor tension borne by the pile body, reducing concentrated stress, and also preventing the steel strand or cable anchor from slipping or deviating from the predetermined path during the tensioning process.

[0024] Furthermore, the external stiffening rib is fixed to the outer wall of the core tube and extends away from the wide end. An internal stiffening rib is fixed to the narrow end of the pressure-bearing member, and the internal stiffening rib is in contact with the inner wall of the core tube. The pile body includes a steel reinforcement cage, and the external stiffening rib is fixedly connected to the steel reinforcement cage.

[0025] Furthermore, the dowel bolt is a circular steel bar ring. An annular through-hole is provided at the free end of the external stiffening rib, and the annular through-hole is coaxial with the core tube. The dowel bolt is arranged in the annular through-hole and fixedly connected to the steel reinforcement cage.

[0026] In the prior art, the anchor head is arranged outside the pile body, and the cable anchor tension diffuses to the whole pile body through the outside of the pile body; when the steel bracket is arranged inside the pile body, if the cable anchor tension directly acts inside the pile body, the diffusion and radiation range of the cable anchor tension decreases, the stress structure becomes worse, the pressure generated by the cable anchor tension on the pile body becomes larger, and it is easy to cause the pile body to crack;

[0027] In this solution, the core tube is directly welded to the steel reinforcement cage of the pile body through the external stiffening rib, and the welding is strengthened at the joint position. The pressure-bearing member bears the cable anchor tension. The cable anchor tension will not be directly transmitted to the inside of the pile body, but is effectively transmitted outside the main reinforcement of the pile body through the pressure-bearing member, the core tube, the external stiffening rib and the dowel bolt, and acts on the surface of the pile body. In this way, the force transmission mechanism between the formed anchor head and the pile body is the same as that of the traditional external anchor head, ensuring the safety of the overall retaining structure.

[0028] Furthermore, the filling process is also included in step four. The gaps on both sides and the top of the core tube in the installation space are filled with concrete mortar, making the elevation of the position where the installation space is located flush with the elevation of the pile body. Thereby reducing the influence on the structural strength and appearance of the pile body due to the installation space set inside the pile body. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of an external anchor head in the prior art;

[0030] Figure 2 Schematic flow diagram of the present invention;

[0031] Figure 3 Three-dimensional axonometric drawing of the built-in anchor head in Embodiment 1;

[0032] Figure 4 For Figure 3 structural explosion diagram;

[0033] Figure 5This is the installation schematic diagram of the hanging barrel type anchor structure of the present invention;

[0034] Figure 6 This is the three-dimensional axonometric drawing of the adjusting member in Embodiment 2;

[0035] Figure 7 This is the sectional three-dimensional drawing of the adjusting member in Embodiment 2;

[0036] Figure 8 This is the three-dimensional drawing of the built-in anchor head in Embodiment 3;

[0037] Figure 9 is Figure 8 the structural explosion diagram of. Specific Embodiments

[0038] The following is a further detailed description through specific embodiments:

[0039] The reference numerals in the accompanying drawings of the specification include: anchor 11, inclined support 12, anchor cable 13, anchor hole 14, pile body 15, steel reinforcement cage 16, hanging barrel type anchor structure 2, core barrel body 21, external stiffening rib 22, bolt 23, pressure-bearing member body 31, first accommodation hole 311, internal stiffening rib 312, convex spherical surface 313, adjusting member 32, second accommodation hole 321.

[0040] The technical solutions mentioned in the background art are as Figure 1 shown. In the foundation pit adopting the pile-anchor support structure, the construction method of the pile-anchor support structure is as follows:

[0041] Pouring of pile body 15: 1. Prepare the steel reinforcement cage 16 corresponding to the pile body 15 and complete the construction of the pile hole; 2. Place the steel reinforcement cage 16 into the pile hole and pour the concrete of the pile body 15;

[0042] Tensioning of anchor cable 13: Tensioning preparation: Excavate the foundation pit to reach the position where the prestressed anchor cable 13 needs to be arranged, and then successively carry out the work of drilling the anchor hole 14, placing the anchor cable 13, grouting the anchor hole 14, etc.; Tensioning: After the concrete hardness of the pile body 15 meets the tensioning requirements, place the inclined support 12, tension the anchor cable 13, and seal the anchor to obtain the pile-anchor support structure as Figure 1 shown.

[0043] For the convenience of the tensioning construction of the anchor cable 13, the anchor 11 is generally located outside the pile body 15, and a reinforced concrete or inclined support 12 is padded between the anchor 11 and the pile body 15. The height of the reinforced concrete and the inclined support 12 is between 400 mm and 600 mm, and numerous protrusions are formed on the side wall of the foundation pit after tensioning; on the other hand, in order to facilitate the pasting of the external waterproof layer on the side wall of the foundation pit, measures such as shotcrete and bricklaying are also required to level the aforementioned protrusions.

[0044] A fat groove filling layer with a width of 450 mm - 600 mm is formed. Before excavation, it is necessary to consider including the fat groove filling layer in the excavation volume in advance. For large foundation pits with a perimeter of hundreds of meters, it is necessary to increase the excavation volume by thousands of cubic meters and a large amount of support costs, which not only increases the investment and construction period, but also has a greater risk of high-altitude operations (usually scaffolding is erected after excavation), and also increases the pollution and damage to the surrounding rock and soil, which is not conducive to environmental protection, green energy conservation and low carbon, and realizing the sustainable development of urban construction.

[0045] Embodiment 1

[0046] Embodiment 1 is basically as shown in the appendix Figure 3-4 shown, such as Figure 3 - Figure 5 shown, a post-installation method of a hanging barrel type anchor structure for reducing the excavation volume of a foundation pit, in which the hanging barrel type anchor structure 2 is installed on the pile body 15 in a post-installation manner to complete the installation of the pile-anchor support structure, as Figure 2 shown, including the following steps:

[0047] Step 1: Prepare the steel reinforcement cage, and additional circular reinforcement stirrups need to be added at the positions where the hanging barrel type anchor is to be installed; put the steel reinforcement cage into the pile hole and pour the pile body concrete;

[0048] Step 2: Excavate the foundation pit. When the foundation pit is excavated to the position where the prestressed anchor cable is to be tensioned, drill an anchor hole on the pile body through a drilling tool, put the anchor cable into the anchor hole, and grout the anchor hole;

[0049] Step 3: Dig out the concrete at the position on the pile body where the hanging barrel type anchor is to be installed, then cut some of the main bars and stirrups of the steel reinforcement cage, and bend the cut main bars and stirrups outward to form an installation space. The hanging barrel type anchor includes a core barrel. The size of the installation space is adapted to the core barrel. The core barrel is fixedly arranged in the installation space. A pressure-bearing adjustment unit is arranged in the core barrel. External stiffening ribs are fixed outside the core barrel. After the hanging barrel type anchor is placed in the installation space and adjusted in place, the bent pile body steel bars are restored and welded to the external stiffening ribs;

[0050] Step 4: The pressure-bearing member is provided with a first receiving hole, the inner diameter of the first receiving hole is smaller than the anchor, the steel cable passes through the first receiving hole and the anchor in sequence, tension the anchor cable, seal the anchor, and fill it up.

[0051] The pouring process of the pile body 15 of the present invention is basically the same as that of the prior art. The difference is that an installation space is provided in the pile body 15, and the hanging barrel type anchor structure 2 is arranged in the installation space. The installation space is set during the tensioning preparation process. After the work such as drilling the anchor hole 14, placing the anchor cable 13, and grouting the anchor hole 14 is completed, it is necessary to take out some of the concrete around the anchor hole 14, and at the same time cut and bend some of the main bars and stirrups of the steel reinforcement cage 16, so as to form an installation space inside the pile body 15. The size of the installation space should be greater than or equal to the size of the hanging barrel type anchor structure 2.

[0052] The hanging barrel - type anchor structure 2 includes a core barrel and a pressure - bearing adjustment unit. As Figure 3 、 Figure 4 shown, the core barrel includes a core barrel body 21, external stiffening ribs 22 and bolts 23. The core barrel body 21 is a conical structure including a wide end and a narrow end. In this embodiment, the core barrel body 21 is a cone with an included angle of 15° - 25° between the side wall and the axis. It can also be other conical bodies such as a quadrangular pyramid, a hexagonal pyramid, an octagonal pyramid or a dodecagonal pyramid, etc. In this embodiment, the included angle between the side wall and the axis is 20°. The external stiffening ribs 22 include several triangular plates. Through - holes are provided on the triangular plates. One side of the triangular plate is welded to the outer wall of the core barrel body 21 from the narrow end to the wide end. The through - holes are combined with each other to form an annular through - hole. The bolts 23 are arranged in the annular through - hole and welded to the triangular plates. During installation, an appropriate amount of concrete slurry is laid at the bottom of the installation space, and the core barrel body 21 is inserted into the installation space, making the axis of the core barrel body 21 form an angle of 15° - 25° with the horizontal plane. At the same time, the gap between the core barrel below and the installation space is filled with the laid concrete slurry. At the same time, the separated steel bars are reset and welded to the external stiffening ribs 22 and the bolts 23, ensuring that the contact parts between the external stiffening ribs 22 and the bolts 23 and the steel bars are all welded. After installation, the core barrel body 21 is located inside the steel reinforcement cage 16, and the bolts 23 are located outside the steel reinforcement cage 16.

[0053] The pressure - bearing adjustment unit includes a pressure - bearing member. The pressure - bearing member includes a pressure - bearing member body 31 and internal stiffening ribs 312. The pressure - bearing member body 31 is also a conical structure including a narrow end and a wide end. The wide end of the pressure - bearing member is larger than the narrow end of the core barrel body 21. The pressure - bearing member is provided with a first accommodation hole 311. The aperture of the first accommodation hole 311 is smaller than the outer diameter of the anchor 11, so that the anchor 11 can be finely adjusted on the first accommodation hole 311. The pressure - bearing member is fixedly arranged inside the core barrel. The pressure - bearing member and the inner wall of the core barrel enclose an anchor 11 installation cavity. The anchor 11 is fixed in the anchor 11 installation cavity and abuts against the pressure - bearing member. The anchor cable 13 sequentially passes through the core barrel and the first accommodation hole 311 and is fixedly connected to the anchor 11. The contact surface between the pressure - bearing member and the anchor 11 is a plane.

[0054] The specific implementation process is as follows:

[0055] 1. Prepare the steel reinforcement cage 16 corresponding to the pile body 15 and complete the construction of the pile hole;

[0056] 2. Place the steel reinforcement cage 16 into the pile hole and pour the concrete of the pile body 15;

[0057] 3. Excavate the foundation pit, determine the anchor head position by the way of dropping a plumb line, and then successively carry out the work of drilling the anchor hole 14, placing the anchor cable 13, grouting the anchor hole 14, etc.;

[0058] 4. Excavate the concrete at the location of the anchor hole 14 of the pile body 15, cut and break some of the main bars and stirrups of the steel reinforcement cage 16 to form an installation space;

[0059] 5. Lay an appropriate amount of concrete slurry at the bottom of the hanging barrel type anchor structure 2, place the hanging barrel type anchor structure 2 into the installation space and adjust it in place, and then pass the anchor cable 13 through the core tube and the first accommodation hole 311 in sequence. Restore the separated steel bars of the pile body 15 and weld them to the external stiffeners;

[0060] 6. After the concrete hardness of the pile body 15 meets the tensioning requirements, tension the anchor cable 13 so that the angle between the anchor cable 13 and the horizontal plane is the same as the inclination angle of the anchor hole 14, and seal the anchor.

[0061] 7. Use concrete mortar to fill the gaps on both sides and at the top of the core tube in the installation space, so that the elevation of the position where the installation space is located is flush with the elevation of the pile body 15, thereby reducing the influence on the structural strength and appearance of the pile body 15 due to the setting of the installation space in the pile body 15.

[0062] Example 2

[0063] Example 2 is basically the same as Example 1, except that the pressure-bearing adjustment unit further includes a convex spherical surface 313 and an adjusting member 32. The convex spherical surface 313 is placed between the pressure-bearing member body 31 and the adjusting member 32 and abuts against the pressure-bearing member. The convex spherical surface 313 is also provided with a first accommodation hole 311. As shown in Figure 6 、 Figure 7 shown, the contact surface between the convex spherical surface 313 and the pressure-bearing member is a plane, the contact surface between the adjusting member 32 and the convex spherical surface 313 is a concave spherical surface that cooperates with the convex spherical surface 313, the concave spherical surface is slidably connected to the convex spherical surface 313, and the contact surface between the adjusting member 32 and the anchor 11 is a plane. Thus, by the relative sliding of the adjusting member 32 and the convex spherical surface 313, the incident angle of the anchor cable 13 is adjusted. When there is a deviation in the installation of the hanging barrel type anchor structure 2, the adjusting member 32 can slide on the convex spherical surface 313 to drive the anchor 11 to rotate along the center of the anchor hole 14, adjust the incident angle of the anchor cable 13, achieve the purpose of coordinating construction errors and making the angle of the anchor cable 13 unaffected, reduce the installation requirements for the hanging barrel type anchor structure 2, and improve the construction efficiency.

[0064] Example 3

[0065] Example 3 is basically the same as Example 1, except that as shown in Figure 8 、 Figure 9As shown in the figure, the pressure-bearing adjustment unit further includes an adjustment member 32. The adjustment member 32 is arranged between the anchor 11 and the pressure-bearing member and is provided with a second accommodation hole 321 for the anchor cable 13 to pass through. The anchor cable 13 sequentially passes through the first accommodation hole 311 and the second accommodation hole 321 and is fixedly connected to the anchor head. The contact surface between the pressure-bearing member body 31 and the adjustment member 32 is a convex spherical surface 313, and the contact surface between the adjustment member 32 and the pressure-bearing member is a concave spherical surface that cooperates with the convex spherical surface 313. The concave spherical surface is slidably connected to the convex spherical surface 313. The contact surface between the adjustment member 32 and the anchor 11 is a plane. Through the special design of the contact surfaces of the pressure-bearing member, the convex spherical surface 313, and the adjustment member 32, when there is a deviation in the installation of the hanging barrel type anchor structure 2, the adjustment member 32 can slide on the convex spherical surface 313, or the convex spherical surface 313 can relatively move on the pressure-bearing member, driving the anchor 11 to rotate along the center of the anchor hole 14, adjusting the incident angle of the anchor cable 13, achieving the purpose of coordinating construction errors and ensuring that the angle of the anchor cable 13 is not affected, reducing the installation requirements of the hanging barrel type anchor structure 2, and improving the construction efficiency.

[0066] The above are only embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics well known in the art are not described in detail here. It should be noted that the technical means for solving problems in the above embodiments of the present invention can be combined to solve multiple technical problems at the same time. For those skilled in the art, without departing from the technical solution of the present invention, several deformations and improvements can still be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application shall be subject to the content of its claims, and the specific implementation manners described in the specification can be used to explain the content of the claims.

Claims

1. A post-installation method of a hanging barrel type anchor structure for reducing the amount of foundation pit excavation, characterized in that: The following steps are involved: Step 1: Prepare the steel cage. Add annular reinforcing stirrups at the location where the hanging barrel anchor needs to be installed; place the steel cage into the pile hole and pour the pile concrete; Step 2: excavate the foundation pit. When the foundation pit is excavated to the predetermined position for tensioning the anchor cable, an anchor hole is drilled on the pile body by a drilling tool, the anchor cable is placed in the anchor hole, and grouting is performed on the anchor hole; Step 3: dig out the concrete at the position where the hanging barrel anchor needs to be installed on the pile body, then cut the main bars and stirrups of the steel cage, and bend the cut main bars and stirrups outward to form an installation space. The hanging barrel anchor includes a core tube, the size of the installation space is adapted to the core tube, the core tube is fixedly arranged in the installation space, a pressure adjustment unit is arranged in the core tube, and an external stiffening rib is fixed outside the core tube. After the hanging barrel anchor is placed in the installation space and adjusted in place, the split pile body steel bars are restored and welded to the external stiffening ribs; Step 4: A first accommodating hole is provided on the pressure-bearing part, the inner diameter of the first accommodating hole is smaller than the anchor, the steel cable passes through the first accommodating hole and the anchor in sequence, the anchor cable is tensioned, and the anchor is sealed.

2. A post-installation method for a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 1, characterized in that: The core tube includes a core tube body and a pin, the external stiffening rib is fixedly arranged on the core tube body, the pin is annular and fixedly arranged on the free end of the external stiffening rib, and the steel cage includes main steel bars, which pass between the core tube body and the pin and are fixedly connected to the stiffening rib.

3. A post-installation method for a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 2, characterized in that: The pressure-bearing regulating unit includes a pressure-bearing part, which is provided with a first accommodating hole. The pressure-bearing part is fixedly arranged in the core tube. The pressure-bearing part and the inner wall of the core tube together form an anchor installation cavity. The anchor is fixed in the anchor installation cavity. The anchor cable passes through the core tube and the first accommodating hole in sequence and is fixedly connected to the anchor.

4. A post-installation method for a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 3, characterized in that: The pressure-bearing adjustment unit also includes an adjusting member, which is arranged between the anchor and the pressure-bearing member and is provided with a second accommodating hole for the anchor cable to pass through, the anchor cable passes through the first accommodating hole and the second accommodating hole in sequence and is fixedly connected to the anchor head, the contact surface between the pressure-bearing member and the adjusting member is a convex spherical surface, the contact surface between the adjusting member and the pressure-bearing member is a concave spherical surface matching the convex spherical surface, the concave spherical surface is slidably connected to the convex spherical surface, and the contact surface between the adjusting member and the anchor is a plane.

5. A post-installation method for a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 4, characterized in that: The core tube is a conical structure, which includes a narrow end and a wide end. The narrow end extends into the installation space, and the wide end is fixedly connected to the pile body. The pressure-bearing part is sleeved in the core tube and fits with the inner wall of the core tube. The angle between the axis of the conical structure and the horizontal plane is 15°-25°.

6. A post-installation method for a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 5, characterized in that: The core tube is a cone, the angle between the side wall of the cone structure and the axis is 15°-25°, and the reinforcement is rotatably arranged in the core tube.

7. A post-installation method for a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 6, characterized in that: The external stiffening rib is fixed on the outer wall of the core tube and extends away from the wide end. The narrow end of the pressure-bearing member is fixed with an internal stiffening rib, which fits the inner wall of the core tube. The pile body includes a steel cage, and the external stiffening rib is fixedly connected to the steel cage.

8. The post-installation method of a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 7 is characterized in that: The pin is a circular steel ring, and a circular through hole is arranged at the free end of the external stiffening rib. The circular through hole is coaxial with the core tube, and the pin is arranged in the circular through hole and fixedly connected with the steel cage.

9. The post-installation method of a hanging barrel type anchor structure for reducing the amount of foundation pit excavation according to claim 1 is characterized in that: Step four also includes a filling process, in which the gaps on both sides and the top of the core tube in the installation space are filled with concrete mortar so that the vertical surface of the installation space is flush with the vertical surface of the pile body.

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