Fabricated composite retaining structure of foundation pit pile wall and construction method thereof

Abstract

The application discloses an assembled foundation pit pile wall composite enclosure structure and a construction method thereof, which comprises prefabricated piles, prefabricated shear wall plates and anchor rods, and the construction process flow is as follows: a. prefabricated piles are punched; b. earthwork is excavated in layers; c. triangular support steel frames are installed on the pile body; d. channel steel joists are installed; e. the prefabricated shear wall plates are hoisted; f. temporary fixing plates are installed; g. grouting is carried out; h. anchor rods are punched; i. the temporary fixing plates are removed; j. grouting is supplemented; structure surfaces are leveled; k. the triangular support steel frames and the channel steel joists are removed; l. steps b to k are repeated in sequence until the whole structure hoisting is completed; m. waterproof construction is carried out; and n. acceptance is carried out. The triangular support steel frames and the channel steel joists are effectively arranged, hoisting elevation positioning and support bearing effects are achieved, layer-by-layer and section-by-section hoisting support is realized, the prefabricated piles are convenient to assemble and disassemble, hoisting errors are easy to adjust, the whole structure design is reasonable, the prefabricated construction efficiency is high, the prefabricated construction is safe and reliable, hoisting speed is fast, and the application provides a new technical method for the prefabricated foundation pit construction in China.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of prefabricated buildings, and particularly relates to a prefabricated foundation pit pile wall composite enclosure structure and a construction method thereof. BACKGROUND

[0002] Prefabricated construction technology is a major change to the traditional wet operation construction method, and has significant social benefits in improving the construction operation environment and improving the level of civilized construction. In recent years, the national housing department has introduced a series of laws, regulations and related provisions, and gradually promotes the application of prefabricated construction technology in new domestic buildings. Prefabricated construction technology has become a major issue in the current transformation and upgrading of the construction industry. The application of prefabricated construction technology in the main body of the building structure has achieved outstanding results, and the development of innovative technologies in the field of underground structure construction is also very important.

[0003] The related complete prefabricated foundation pit enclosure structure technology of "a prefabricated pile-anchoring rod integrated foundation pit enclosure structure construction method (CN107178085B)", "a prefabricated pile-anchoring rod integrated foundation pit enclosure structure construction method (CN107178086B)", "a H-shaped steel anchoring rod composite pile-prefabricated plate wall foundation pit enclosure structure construction method (CN108222017B)", "an improved H-shaped steel anchoring rod composite pile-prefabricated plate wall foundation pit enclosure structure construction method (CN108487255B)" and the like disclosed by Jiangsu Engineering Vocational and Technical College Gao Heng has significant significance for the application of prefabricated structures to foundation pit enclosure structures and the promotion of the reform of the construction method in a larger range of the industry. However, in the application process of specific actual engineering projects, it is found that the existing technology needs to use more support devices when hoisting the prefabricated components, the support devices are not easy to install, the anchoring rod setting has a greater impact on the hoisted prefabricated structure, and the safety is not high and the cost is increased. The present application can realize "hoisting and fixing at the same time", the process is optimized, the construction is convenient, and the problem is effectively solved. More new technologies, new processes and new methods close to the site construction are developed in the application and improvement of the technology, and the school-enterprise joint research and development make greater contributions to the application of prefabricated construction technology in China. SUMMARY

[0004] The purpose of the present application is to provide a prefabricated foundation pit pile wall composite enclosure structure and a construction method thereof to solve the problems in the background art.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] An assembled foundation pit pile wall composite enclosure structure, comprising a prefabricated pile, a prefabricated shear wall plate, an anchor rod; both sides of the prefabricated shear wall plate are provided with the prefabricated pile, the inside of the prefabricated shear wall plate is provided with a plurality of anchor rods, two adjacent prefabricated shear wall plates are connected through a temporary fixing plate, the bottom of the prefabricated shear wall plate is provided with a channel steel joist, the inside of the channel steel joist is provided with a ribbed plate, the channel steel joist and the prefabricated pile are connected through a tension bolt, and the prefabricated pile is provided below the channel steel joist with a triangular support steel frame.

[0007] A construction method of an assembled foundation pit pile wall composite enclosure structure, comprising the following steps:

[0008] a. Punch the prefabricated pile, b. Excavate the earth in layers, c. Install the triangular support steel frame on the pile body, d. Install the channel steel joist, e. Hoist the prefabricated shear wall plate, f. Install the temporary fixing plate, g. Grouting, h. Punch the anchor rod, i. Remove the temporary fixing plate, j. Grouting and structure surface leveling, k. Remove the triangular support steel frame and the channel steel joist, l. Repeat steps b to k in turn until the whole structure is hoisted, m. Waterproof construction, n. Acceptance, the specific steps are as follows:

[0009] a. Punch the prefabricated pile, in order to better realize the rapid construction of the subsequent process, the pile body at the connection between the prefabricated pile and the channel steel joist is provided with a reserved hole, and the pile body at the connection between the prefabricated pile and the triangular support steel frame is provided with a threaded connection sleeve, before punching the prefabricated pile, the reserved hole and the threaded connection sleeve of the pile body of the prefabricated pile are sealed with rubber plugs to prevent the reserved hole and the threaded connection sleeve from being blocked during piling; The prefabricated pile is punched mainly to control the elevation, the adjacent pile body is controlled within 10mm in error with the pile top elevation as the standard, and the verticality of the prefabricated pile is strictly controlled, the error of the verticality does not exceed 1% of the height of the prefabricated pile, and the prefabricated pile is punched from the middle to both sides of the foundation pit side, avoiding the use of hammering pile method;

[0010] b. Excavate the earth in layers, after the prefabricated pile is completely punched, first excavate the first layer of earth in layers, the layering thickness is determined according to the soil condition, the layering thickness of the earth is the height of the prefabricated wall plate + the height of the channel steel joist + the height of the triangular support steel frame + 200mm, during the earth excavation process, the earth inside the foundation pit outside the pile is excavated by machine, a little earth inside the pile is cleaned by hand, do not disturb the soil body at the edge of the foundation pit in a large area, after the first layer of earth is excavated, the miscellaneous soil on the pile body is cleaned in time, and the rubber plug in the reserved hole and the threaded connection sleeve on the pile body of the prefabricated pile is pulled out;

[0011] c. pile body installation triangle support steel frame, the first layer of earthwork is completed, check the adjacent precast pile body elevation, the reserved hole, threaded connection sleeve position elevation of the pile body, when the adjacent precast pile body elevation error is larger, the precast pile is adjusted again, in order to ensure the installation quality and installation efficiency of the channel steel support beam, first install the threaded connection sleeve of each precast pile body with triangle support steel frame, after the installation of all triangle support steel frame is completed, check the top elevation difference of triangle support steel frame on the adjacent precast pile, the elevation difference is within 8mm, when the top elevation difference of triangle support steel frame after installation exceeds the allowable difference, set "elastic gasket" at the smaller value of triangle support steel frame top elevation to adjust the elevation error;

[0012] d. installation of channel steel support beam, the installation of triangle support steel frame provides convenience for the hoisting of channel steel support beam, the top elevation of triangle support steel frame after installation is the in-place elevation of channel steel support beam, the channel steel support beam is directly placed on the triangle support steel frame, and then the tension bolt is passed through the reserved hole of the precast pile body and fixed, the triangle support steel frame not only defines the hoisting position of the channel steel support beam, but also supports part of the load of the channel steel support beam, the channel steel support beam is installed in place with the channel opening facing the inside of the foundation pit, and at least 3 ribbed plates are arranged in each channel steel support beam, when the distance between adjacent precast piles is large, a large gap will be left between the channel steel support beam and the precast pile after the channel steel support beam is installed, at this time, the hole is adjusted by a hole steel gasket and a hole rubber gasket before the tension bolt is passed through, and the top surface of the channel steel support beam is coated with a release agent;

[0013] e. hoisting of precast shear wall plate, after the installation of channel steel support beam is completed, the precast shear wall plate is hoisted and installed on the top surface of the channel steel support beam, the side of the precast shear wall plate facing the inside of the foundation pit is flush with the surface of the precast pile, in order to facilitate the rapid installation of the precast shear wall plate, an angle steel positioning plate is arranged on the top surface of the channel steel support beam, which effectively controls the hoisting and installation of the precast shear wall plate, and the angle steel positioning plate serves as a temporary support device for the precast shear wall plate;

[0014] f. installation of temporary fixing plate, after the precast shear wall plate is hoisted and installed in modules, the adjacent precast shear wall plates are fixed by using temporary fixing plates, the temporary fixing plates are connected and fixed at the threaded connection sleeves of the adjacent precast shear wall plates, and one temporary fixing plate is arranged every 600mm along the length direction of the precast pile, the temporary fixing plate is installed and fixed immediately after the precast shear wall plate is installed, when the adjacent precast shear wall plates are installed with a large error, the installation hole of the temporary fixing plate is set to be flat and round, and after the fixed position is determined, a hole pad plate is attached to the outside of the temporary fixing plate for flexible adjustment;

[0015] g. Grouting: After the temporary fixing plate is installed and the overall position of the precast shear wall panel is finely adjusted, grouting is first carried out at the joint between the precast pile and the precast shear wall panel. An appropriate amount of quick-setting agent is added to the grouting material. After the grouting material reaches a strength of more than 80%, steel pipes are inserted into the reserved anchor holes on the precast shear wall panel. The surface of the steel pipe is coated with a release agent. The steel pipe is driven into the soil layer for no less than 250mm. A lower hole is left without a steel pipe and is used as a grouting hole. The grouting hole left at the bottom of the precast shear wall panel is selected from the middle hole of the wall panel. High-pressure grouting is carried out through the grouting hole and then the hole is sealed.

[0016] h. Install anchor bolts. After grouting is completed, rotate the steel pipe in the anchor bolt hole and pull it out. Then proceed with anchor bolt construction. During anchor bolt construction, do not disturb the precast shear wall panel excessively or damage it. In order to ensure the appearance quality of the precast shear wall panel after anchor bolt construction, the anchor bolt holes on the precast shear wall panel are set as embedded enlarged holes. The depth of the enlarged holes should be sufficient to ensure that the anchor bolts are concealed inside the wall panel after sealing and do not affect the appearance quality.

[0017] i. Remove the temporary fixing plates. After the anchor bolt construction is completed and the overall grouting material reaches its strength, remove and reuse the temporary fixing plates. Remove the temporary fixing plates one by one from top to bottom. If the removal is difficult, do not pry them too hard. After the removal is completed, clean up in time and reuse them in time.

[0018] j. Grouting and leveling of structural surfaces: After removing the temporary fixing plates, the assembly and hoisting of the first floor is basically completed. At this time, grouting and leveling are carried out on the threaded sleeve holes and joints on the structural surface to prepare for the overall waterproofing of the subsequent structure.

[0019] k. After dismantling the triangular support steel frame and channel steel support beam, and leveling the structural surface, complete the process acceptance work. Remove the triangular support steel frame and channel steel support beam. First, place some wooden blocks on the channel steel support beam. After removing the triangular support steel frame, loosen the tie bolts and remove the channel steel support beam. Clean up the removed triangular support steel frame and channel steel support beam and reuse them in a timely manner.

[0020] l. Repeat steps b to k in sequence until the overall structure hoisting is completed;

[0021] m. Waterproofing construction: After all prefabricated hoisting construction is completed, and when the underground soil layer is relatively abundant, the foundation pit retaining structure is waterproofed in conjunction with the foundation pit retaining structure and the basement exterior wall. The waterproofing construction should fully consider the direction of the groundwater level. First, a cold primer is applied to the surface of the prefabricated foundation pit structure. The cold primer is applied horizontally and vertically on two sides, and then the waterproof membrane is laid. The waterproof membrane is laid in layers from top to bottom. Due to the influence of groundwater, the upper layer of waterproof membrane is laid first, and then the lower layer is laid. The overlap length between adjacent membranes meets the standard requirements.

[0022] n. acceptance.

[0023] Technical effects and advantages of the present application:

[0024] The present application effectively sets triangular support steel frames and channel steel joists, plays a hoisting elevation positioning and support bearing role, realizes layer-by-layer and section-by-section hoisting support, is convenient to assemble and disassemble, is easy to adjust hoisting error, has reasonable structure design, high assembly construction efficiency, high green construction level, safety and reliability, can effectively shorten the construction period, provides a new technical method for assembly type foundation pit construction in China, and has good economic benefits and social benefits. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 It is a schematic diagram of the overall structure of the present application.

[0026] Fig. 2 It is a flowchart of the present application.

[0027] In the figure: 1, precast pile; 2, precast shear wall plate; 3, anchor rod; 4, channel steel joist; 5, ribbed plate; 6, triangular support steel frame; 7, tension bolt; 8, temporary fixing plate. EMBODIMENT

[0028] The following will be combined with the drawings of the embodiments of the present application to Figs. 1-2 The technical solutions in the embodiments of the present application are described clearly and completely, obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. The specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. EMBODIMENT

[0029] As Figs. 1-2 shown, the present application provides an assembly type foundation pit pile wall composite enclosure structure, which comprises a precast pile 1, a precast shear wall plate 2 and an anchor rod 3; the precast pile 1 is arranged on both sides of the precast shear wall plate 2, the anchor rod 3 is arranged in the precast shear wall plate 2, the adjacent two precast shear wall plates 2 are connected through the temporary fixing plate 8, the channel steel joist 4 is arranged at the bottom of the precast shear wall plate 2, the ribbed plate 5 is arranged in the channel steel joist 4, the channel steel joist 4 and the precast pile 1 are connected through the tension bolt 7, and the triangular support steel frame 6 is arranged below the channel steel joist 4.

[0030] A construction method of an assembly type foundation pit pile wall composite enclosure structure, comprising the following steps:

[0031] a. Set the precast pile 1 - b. Excavate the earth in layers - c. Install the triangular support steel frame 6 on the pile body - d. Install the channel steel joist 4 - e. Hoist the precast shear wall plate 2 - f. Install the temporary fixing plate 8 - g. Grouting - h. Set the anchor rod 3 - i. Remove the temporary fixing plate 8 - j. Grouting, structure surface leveling - k. Remove the triangular support steel frame 6 and the channel steel joist 4 - l. Repeat steps b to k in turn until the overall structure hoisting is completed - m. Waterproof construction - n. Acceptance, the specific steps are as follows:

[0032] a. Set the precast pile 1, in order to better realize the rapid construction of the subsequent process, the pile body at the connection between the precast pile 1 and the channel steel joist 4 is provided with a reserved hole, and the pile body at the connection between the precast pile 1 and the triangular support steel frame 6 is provided with a threaded connection sleeve. Before setting the precast pile 1, the reserved hole and the threaded connection sleeve of the pile body of the precast pile 1 are sealed with rubber plugs to prevent the reserved hole and the threaded connection sleeve from being blocked during piling. The precast pile 1 is set mainly to control the elevation, the adjacent piles are controlled with the pile top elevation as the standard, the error is within 10mm, and the verticality of the precast pile 1 is strictly controlled, the verticality error is not more than 1% of the height of the precast pile 1. The precast pile 1 is set from the middle of the side edge of the foundation pit to both sides to avoid using hammering pile driving method;

[0033] b. Excavate the earth in layers, after the precast pile 1 is completely set, first excavate the first layer of earth in layers, the thickness of the earth in layers is determined according to the soil condition, the thickness of the earth in layers is the height of the precast wall plate + the height of the channel steel joist 4 + the height of the triangular support steel frame 6 + 200mm. During the earth excavation process, the earth inside the foundation pit outside the pile is excavated by machine, and a little earth inside the pile is cleaned by hand. Do not disturb the soil at the edge of the foundation pit on a large scale. After the first layer of earth is excavated, the miscellaneous soil on the pile body is cleaned in time, and the rubber plugs in the reserved hole and the threaded connection sleeve of the pile body of the precast pile 1 are pulled out;

[0034] c. Install the triangular support steel frame 6 on the pile body, after the first layer of earth is excavated, check the elevation of the pile body of each adjacent precast pile 1, the elevation of the position of the reserved hole and the threaded connection sleeve of the pile body. When the elevation error of the pile body of the adjacent precast pile 1 is large, adjust the precast pile 1 again. In order to ensure the installation quality and efficiency of the channel steel joist 4, install the triangular support steel frame 6 at the threaded connection sleeve of each precast pile 1 pile body first. After all the triangular support steel frames 6 are installed, check the elevation difference of the top surface of the triangular support steel frame 6 on the adjacent precast pile 1. When the elevation difference of the top surface of the installed triangular support steel frame 6 exceeds the allowable difference, set "elastic shims" at the lower value of the top surface elevation of the triangular support steel frame 6 to adjust the elevation error;

[0035] d. The installation of the channel steel joist 4 and the triangular support steel frame 6 provides convenience for the hoisting of the channel steel joist 4 into position. The top surface elevation of the triangular support steel frame 6 after installation is the elevation of the channel steel joist 4 in position. The channel steel joist 4 is directly placed on the triangular support steel frame 6, and the tension bolt 7 is immediately inserted through the reserved hole of the pile body of the precast pile 1 and fixed. The triangular support steel frame 6 not only determines the hoisting position of the channel steel joist 4, but also supports part of the load of the channel steel joist 4. The channel of the channel steel joist 4 is towards the inside of the foundation pit. Each channel steel joist 4 is provided with at least three ribbed plates 5. When the distance between adjacent precast piles 1 is large, a large gap will be left between the channel steel joist 4 and the precast pile 1 after the channel steel joist 4 is in position. At this time, the hole of the tension bolt 7 is adjusted by a hole steel gasket and a hole rubber gasket before being inserted. The top surface of the channel steel joist 4 is coated with a release agent;

[0036] e. Hoist the precast shear wall panel 2. After the installation of the channel steel joist 4 is completed, hoist the precast shear wall panel 2. The precast shear wall panel 2 is located on the top surface of the channel steel joist 4. The side of the precast shear wall panel 2 facing the inside of the foundation pit is flush with the surface of the precast pile 1. In order to facilitate the quick positioning of the precast shear wall panel 2, an angle steel positioning plate is arranged on the top surface of the channel steel joist 4. The angle steel positioning plate effectively controls the hoisting and positioning of the precast shear wall panel 2. At the same time, the angle steel positioning plate serves as a temporary support device for the precast shear wall panel 2.

[0037] f. Install the temporary fixing plate 8. After the precast shear wall panel 2 is hoisted and positioned in modules, the adjacent precast shear wall panels 2 are fixed by the temporary fixing plate 8. The temporary fixing plate 8 is connected and fixed at the threaded connection sleeve of the adjacent precast shear wall panels 2. The temporary fixing plate 8 is installed at an interval of 600 mm along the long direction of the precast pile 1. The temporary fixing plate 8 is installed immediately after the precast shear wall panel 2 is positioned. When the adjacent precast shear wall panels 2 are positioned with a large error, the installation hole of the temporary fixing plate 8 is set as a flat round type. After the fixed position is determined, a hole gasket is attached to the outside of the temporary fixing plate 8 for flexible adjustment.

[0038] g. Grouting. After the installation of the temporary fixing plate 8 is completed and the overall position of the precast shear wall panel 2 is adjusted, the gap between the precast pile 1 and the precast shear wall panel 2 is first grouted. The grouting material is mixed with a suitable amount of accelerator. After the strength of the grouting material reaches more than 80%, a steel pipe is inserted into the reserved anchor rod hole of the precast shear wall panel 2. The surface of the steel pipe is coated with a release agent. The steel pipe is driven into the soil layer by not less than 250 mm, and a lower hole is left without a steel pipe as a grouting hole. The grouting hole left at the lower part of the precast shear wall panel 2 is selected from the middle hole of the wall panel. High-pressure grouting construction is carried out through the grouting hole and the hole is sealed.

[0039] h. Set anchor rod 3, after grouting is completed, rotate the steel pipe in the anchor rod hole and pull out, immediately carry out anchor rod 3 construction, anchor rod 3 construction cannot excessively disturb prefabricated shear wall plate 2, cannot damage shear wall plate, in order to ensure the appearance quality of prefabricated shear wall plate 2 after the construction of anchor rod 3 is completed, the anchor rod hole on prefabricated shear wall plate 2 is set as an embedded enlarged hole position, the depth of the enlarged hole position can ensure that anchor rod 3 is hidden in the wall plate after sealing anchor without affecting the appearance quality;

[0040] i. Remove temporary fixing plate 8, anchor rod 3 construction is completed, after the overall grouting material reaches the strength, remove and circulate temporary fixing plate 8, remove temporary fixing plate 8 from top to bottom, do not pry when it is difficult to remove, clean up in time after removal and circulate in time;

[0041] j. Grouting, structure surface leveling, after removing temporary fixing plate 8, the first layer of assembly hoisting has been basically completed, at this time, the threaded sleeve hole and the joint position and other positions on the structure surface are grouted and leveled to prepare for the subsequent overall waterproofing of the structure;

[0042] k. Remove triangular support steel frame 6 and channel steel joist 4, after structure surface leveling, complete process acceptance, remove triangular support steel frame 6 and channel steel joist 4, first set part of the cushion in channel steel joist 4, after removing triangular support steel frame 6, loosen the tension bolt 7 and remove the channel steel joist 4, and clean up the removed triangular support steel frame 6 and channel steel joist 4 for timely circulation;

[0043] l. Repeat steps b to k in turn until the overall structure hoisting is completed;

[0044] m. Waterproof construction, after the completion of the overall assembly hoisting construction, in the case of sufficient underground soil layer, waterproof treatment is carried out on the foundation pit support structure in combination with the foundation pit support and the basement outer wall, the waterproof construction fully considers the underground water level line type, first, cold primer is used for bottom treatment on the surface of the assembly foundation pit structure, the cold primer oil is cross-coated in horizontal and vertical directions, then waterproof roll material is laid, the waterproof roll material is laid in layers from top to bottom, due to the influence of underground water, the waterproof roll material is laid from top to bottom, and the overlapping length between adjacent roll materials meets the standard requirements;

[0045] n. Acceptance.

[0046] The triangular support steel frame and the channel steel joist are effectively arranged, which plays the role of hoisting elevation positioning and support bearing, realizes layer-by-layer and section-by-section hoisting support, is convenient to assemble and disassemble, is easy to adjust hoisting error, has reasonable structure design, high assembly construction efficiency, high green construction level, safety and reliability, can effectively shorten the construction period, provides a new technical method for the assembly foundation pit construction in China, and has good economic benefit and social benefit.

[0047] It should be pointed out finally that the above merely relates to preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that modifications can be made to the technical solutions described in the foregoing embodiments, or some of the technical features thereof can be replaced equivalently, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A construction method for a prefabricated pile-wall composite retaining structure for foundation pits, comprising precast piles, precast shear wall panels, and anchor bolts; characterized in that: The precast shear wall panel has precast piles on both sides, and several anchor rods are installed inside the precast shear wall panel. Two adjacent precast shear wall panels are connected by temporary fixing plates. A channel steel support beam is installed at the bottom of the precast shear wall panel. The channel steel support beam has ribs installed inside. The channel steel support beam is connected to the precast piles by tie bolts. A triangular support steel frame is installed below the channel steel support beam for the precast piles. Includes the following steps: a. Driving precast piles -- b. Layered excavation -- c. Installing triangular support steel frames on piles -- d. Installing channel steel support beams -- e. Hoisting precast shear wall panels -- f. Installing temporary fixing plates -- g. Grouting -- h. Driving anchor bolts -- i. Removing temporary fixing plates -- j. Grouting and leveling the structural surface -- k. Removing the triangular support steel frames and channel steel support beams -- l. Repeating steps b to k in sequence until the overall structure hoisting is completed -- m. Waterproofing construction -- n. Acceptance, the specific steps are as follows: a. Precast piles are driven. To facilitate rapid construction of subsequent processes, the precast piles are equipped with pre-drilled holes at the connection points with the channel steel support beams, and threaded sleeves are provided at the connection points with the triangular support steel frames. Before driving the precast piles, the pre-drilled holes and threaded sleeves are sealed with rubber plugs to prevent them from being blocked during the driving process. The driving of precast piles is mainly based on controlling the elevation. The error between adjacent piles is controlled within 10mm based on the top elevation of the pile. The verticality of the precast piles is strictly controlled, and the verticality error does not exceed 1% of the height of the precast pile. The precast piles are driven from the middle of the side of the foundation pit to both sides, avoiding the use of hammer driving method. b. Layered excavation of earthwork: After all the precast piles have been driven, the first layer of earthwork is excavated in layers. The thickness of each layer is determined according to the soil conditions. The thickness of each layer of earthwork is the height of the precast wall panel + the height of the channel steel support beam + the height of the triangular support steel frame + 200mm. During the earthwork excavation, mechanical excavation is used to excavate the earthwork inside the foundation pit outside the pile. A small amount of earthwork inside the pile is cleaned manually. Do not disturb the soil at the edge of the foundation pit on a large scale. After the first layer of earthwork is excavated, clean up the debris on the pile body in time and remove the rubber plugs from the reserved holes and threaded connection sleeves on the precast pile body. c. Install triangular support steel frames on the pile body. After the first layer of earthwork excavation is completed, check the elevation of each adjacent precast pile body, the elevation of the reserved holes and threaded connection sleeves of the pile body. When the elevation error of adjacent precast pile bodies is large, the precast piles are driven and adjusted a second time. In order to ensure the installation quality and efficiency of the channel steel support beam, first install the triangular support steel frames at the threaded connection sleeves of each precast pile body. After all the triangular support steel frames are installed, check the elevation difference of the top surface of the triangular support steel frames on the adjacent precast pile bodies. The elevation difference should be within 8mm. When the elevation difference of the top surface of the installed triangular support steel frames exceeds the allowable difference, set "elastic shims" at the smaller elevation of the top surface of the triangular support steel frames to adjust the elevation error. d. Installing the channel steel support beam: The installation and fixing of the triangular support steel frame facilitates the hoisting and positioning of the channel steel support beam. The top elevation of the triangular support steel frame after installation is the positioning elevation of the channel steel support beam. The channel steel support beam is placed directly on the triangular support steel frame, and the tie bolts are then passed through the reserved holes in the precast pile body and fixed. The triangular support steel frame clarifies the hoisting position of the channel steel support beam and also supports and bears part of the load of the channel steel support beam. The slot of the channel steel support beam faces the inside of the foundation pit. Each channel steel support beam has at least 3 ribs inside. When the distance between adjacent precast piles is large, a large gap will be left between the channel steel support beam and the precast pile after the channel steel support beam is positioned. In this case, before the tie bolts are inserted, the gap is adjusted by using perforated steel shims and perforated rubber shims. The top surface of the channel steel support beam is coated with a release agent. e. Hoisting and installing precast shear wall panels: After the channel steel support beam is installed, the precast shear wall panels are hoisted and installed. The precast shear wall panels are located on the top surface of the channel steel support beam, with the side of the precast shear wall panel facing into the foundation pit flush with the surface of the precast pile. To facilitate the rapid positioning of the precast shear wall panels, angle steel positioning plates are installed on the top surface of the channel steel support beam. The installation of angle steel positioning plates effectively controls the hoisting and positioning of the precast shear wall panels, and at the same time, the angle steel positioning plates serve as temporary support devices for the precast shear wall panels. f. Install temporary fixing plates. After the precast shear wall panels are hoisted into place in modules, temporary fixing plates are used to fix each adjacent precast shear wall panel. Temporary fixing plates are installed at 600mm intervals along the length of the precast pile. The temporary fixing plates are installed and fixed immediately after the precast shear wall panels are in place. When the error between adjacent precast shear wall panels is large, the mounting holes on the temporary fixing plates are set to flat round shape. After the fixing position is determined, a perforated pad is added to the outside of the temporary fixing plate for flexible adjustment. g. Grouting: After the temporary fixing plate is installed and the overall position of the precast shear wall panel is finely adjusted, grouting is first carried out at the joint between the precast pile and the precast shear wall panel. An appropriate amount of quick-setting agent is added to the grouting material. After the grouting material reaches a strength of more than 80%, steel pipes are inserted into the reserved anchor holes on the precast shear wall panel. The surface of the steel pipe is coated with a release agent. The steel pipe is driven into the soil layer for no less than 250mm. A lower hole is left without a steel pipe and is used as a grouting hole. The grouting hole left at the bottom of the precast shear wall panel is selected from the middle hole of the wall panel. High-pressure grouting is carried out through the grouting hole and then the hole is sealed. h. Install anchor bolts. After grouting is completed, rotate the steel pipe in the anchor bolt hole and pull it out. Then proceed with anchor bolt construction. During anchor bolt construction, the precast shear wall panel should not be disturbed excessively or damaged. In order to ensure the appearance quality of the precast shear wall panel after anchor bolt construction, the anchor bolt holes on the precast shear wall panel are set as embedded enlarged holes. The depth of the enlarged holes should be sufficient to ensure that the anchor bolts are concealed inside the wall panel after sealing and do not affect the appearance quality. i. Remove the temporary fixing plates. After the anchor bolt construction is completed and the overall grouting material reaches its strength, remove and reuse the temporary fixing plates. Remove the temporary fixing plates one by one from top to bottom. If the removal is difficult, do not pry them too hard. After the removal is completed, clean up in time and reuse them in time. j. Grouting and leveling of the structural surface: After removing the temporary fixing plate, the assembly and hoisting of the first floor is basically completed. At this time, the threaded sleeve holes and joints on the structural surface are grouted and leveled to prepare for the overall waterproofing of the structure. k. After dismantling the triangular support steel frame and channel steel support beam, and leveling the structural surface, complete the process acceptance work. Remove the triangular support steel frame and channel steel support beam. First, place some wooden blocks on the channel steel support beam. After removing the triangular support steel frame, loosen the tie bolts and remove the channel steel support beam. Clean up the removed triangular support steel frame and channel steel support beam and reuse them in a timely manner. l. Repeat steps b to k in sequence until the overall structure hoisting is completed; m. For waterproofing construction, apply a cold primer, then apply two coats each horizontally and vertically, and lay the waterproof membrane in layers from top to bottom, ensuring that the overlap length of adjacent membranes meets the standard. n. Acceptance inspection.

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