Anchoring type anti-sliding pile foundation joist retaining wall composite structure and construction method thereof

Abstract

The invention discloses an anchoring type anti-sliding pile foundation joist retaining wall composite structure and a construction method thereof, and belongs to the technical field of high fill slope supporting of constructional engineering, and the construction method of the anchoring type anti-sliding pile foundation joist retaining wall comprises the steps of site surface cleaning and leveling and foundation excavation; anti-slide piles and soil retaining plates are constructed; gravel is backfilled between the piles, soil is backfilled behind the piles, and pre-stressed anchor cables are drilled, tensioned and locked; after the fill below the pile top is constructed, the pre-stressed anchor cable is tensioned for the second time; constructing a continuous beam and a joist on the pile; and pouring the balance-weight retaining wall. Loads on the retaining wall are transmitted to the slide-resistant piles through the joists, then loads on the upper portion are transmitted to a stable rock-soil body through the pre-stressed anchor cables, the whole structure is jointly stressed and deforms in a coordinated mode, and therefore safety is improved. The structure has the structural characteristics of an anti-slide pile, a retaining wall and a sheet-pile wall at the same time, and the overall stability problem in high fill slope supporting engineering can be effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of high fill slope support in construction engineering, and in particular to an anchor-pull type anti-slip pile foundation support beam retaining wall composite structure and a construction method thereof. Background Art

[0002] With the rapid development of urbanization, more and more engineering projects have to be located in mountainous and hilly areas. In order to meet the needs of construction sites, the existing topography needs to be filled, which forms high fill slopes. Considering the limited land use range and the overall stability of the slope, the support form of high fill slopes often adopts pile foundation beam retaining wall structure.

[0003] As a new type of retaining structure, pile foundation beam retaining wall is mainly used in retaining projects such as weak foundations or high fill slopes with insufficient foundation bearing capacity. According to the structural force system, it can be divided into the type that improves foundation bearing capacity and the anti-slip type. In the type of pile foundation beam retaining wall that improves foundation bearing capacity, the lower pile foundation is only used to improve the foundation bearing capacity, and the lateral soil pressure is only borne by the retaining wall, which increases the cross-sectional size of the retaining wall and leads to excessively high project costs; in the anti-slip type pile foundation beam retaining wall, the pile foundation not only needs to ensure the foundation bearing capacity, but also needs to share the lateral soil pressure. The top of the traditional anti-slip pile foundation beam retaining wall is in a cantilever state, and the displacement of the pile top is difficult to control, which is not conducive to the stability of itself and the upper retaining wall. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an anchor-pull anti-slip pile foundation support beam retaining wall composite structure and a construction method thereof, which can solve the problems of limited construction site and insufficient foundation bearing capacity and improve structural stability.

[0005] The anchor-pull anti-sliding pile foundation support beam retaining wall composite structure according to the first aspect of the present invention is applied to a slope, the surface of the slope is the existing ground line, the surface layer of the slope is a strongly weathered rock layer, and below the strongly weathered rock layer is a medium weathered rock layer, including: a plurality of anti-sliding piles, the plurality of anti-sliding piles are evenly distributed on the slope along the front-to-back direction, the lower end of each anti-sliding pile is penetrated into the medium weathered rock layer; a prestressed anchor cable, one end of the prestressed anchor cable is anchored on the anti-sliding pile, the other end of the prestressed anchor cable is embedded in the medium weathered rock layer, and the prestressed anchor cable is inclined; a retaining plate, the retaining plate is arranged between two adjacent anti-sliding piles, and the retaining plate and the two adjacent anti-sliding piles together form a trough for accommodating gravel; a support beam, the support beam is arranged at the top of the anti-sliding pile, and a counterweight retaining wall is arranged on the upper end of the support beam, and the counterweight retaining wall, the retaining plate, the anti-sliding piles and the existing ground line together form a backfill area.

[0006] The anchor-pull anti-sliding pile foundation support beam retaining wall composite structure according to the embodiment of the present invention has at least the following beneficial effects: the load on the retaining wall is transferred to the anti-sliding piles through the support beams, and the upper load is then transferred to the stable rock and soil through the prestressed anchor cables, and the overall structure is jointly stressed and deformed in a coordinated manner, thereby improving safety; the structure simultaneously has the structural characteristics of anti-sliding piles, retaining walls, and pile-board walls, and can effectively solve the overall stability problem in high fill slope support projects.

[0007] According to some embodiments of the present invention, a plurality of anti-sliding piles are connected by a continuous beam, and the continuous beam is disposed at the top of the anti-sliding piles.

[0008] According to some embodiments of the present invention, the anti-slide piles are C30 reinforced concrete structures.

[0009] According to some embodiments of the present invention, the distance between adjacent anti-slide piles is 4.5 m to 5 m.

[0010] According to some embodiments of the present invention, the depth to which the anti-slide piles are embedded in the strongly weathered rock strata is greater than or equal to 8 m, and the depth to which the anti-slide piles are embedded in the moderately weathered rock strata is greater than or equal to 1 m.

[0011] According to some embodiments of the present invention, the prestressed anchor cable includes a steel strand, one end of which is provided with an anchor pier, the steel strand is fixed to an anti-slip pile through the anchor pier, and the other end of the steel strand is an anchoring section, which is embedded in the medium-weathered rock formation.

[0012] According to some embodiments of the present invention, the retaining plate is a cast-in-place C30 reinforced concrete structure, and the depth of the retaining plate embedded in the strongly weathered rock layer is greater than or equal to 1 m.

[0013] According to some embodiments of the present invention, a drainage pipe is provided on the retaining board in the vertical direction, and a drainage hole is opened on the drainage board.

[0014] According to some embodiments of the present invention, the joist is a cast-in-place C30 reinforced concrete structure, and the main reinforcement of the anti-sliding piles extends into the joist to form an integral structure.

[0015] The construction method of the anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to the second embodiment of the present invention comprises:

[0016] Step 1: clean the slope surface of the fill slope, determine the positions of multiple anti-slide piles according to the design coordinates of the anti-slide piles, and excavate at the pile foundation positions;

[0017] Step 2: First, tie the steel bars and formwork of the anti-slide piles at the pile foundation position, tie the steel bars and formwork of the retaining plate between adjacent anti-slide piles, and pour concrete in sections to form the anti-slide piles and retaining plate;

[0018] Step 3: Backfill gravel into the trough formed by the retaining plate and two adjacent anti-slide piles, backfill soil behind the anti-slide piles, and evenly distribute multiple prestressed anchor cables along the upper and lower directions of the anti-slide piles. When the backfill soil is compacted to 2m above the anchor head of the first anchor cable at the bottom, perform anchor cable drilling and grouting construction. After the strength of the anchor section of a single anchor cable meets the design requirements, prestress tension and lock it. After tensioning is completed, continue to backfill to 2m above the anchor head of the second prestressed anchor cable, tension and lock it again, and repeat the above steps to complete tensioning of all anchor cables;

[0019] Step 4: After the filling below the pile top is completed according to the design requirements, check the standard value and locking value of the axial force of each prestressed anchor cable, and perform secondary tensioning and locking to eliminate the influence of pile displacement during pile foundation construction;

[0020] Step 5: Tie steel bars and pour concrete on the top of the anti-slide piles to form a continuous beam and a joist;

[0021] Step 6: Cast the counterweight retaining wall on the joists.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0024] Figure 1 It is a schematic flow chart of a construction method of an anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to an embodiment of the present invention;

[0025] Figure 2 2 is a schematic structural diagram of an anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to an embodiment of the present invention;

[0026] Figure 3 yes Figure 2 Top view of the anti-slide piles and retaining wall;

[0027] Figure 4 yes Figure 2 Schematic diagram of the structure of the prestressed anchor cable.

[0028] Reference numerals:

[0029] Anti-sliding pile 110; prestressed anchor cable 120; steel strand 121; anchor pier 122; anchor section 123; retaining plate 130; joist 140; counterweight retaining wall 150; continuous beam 160; backfill area 170; crushed stone 180;

[0030] Current ground line 10; strongly weathered rock layer 20; moderately weathered rock layer 30. DETAILED DESCRIPTION

[0031] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the mechanism or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0035] refer to Figures 1 to 4 The invention describes an anchor-pull type anti-sliding pile foundation joist retaining wall composite structure and a construction method thereof according to an embodiment of the invention.

[0036] like Figures 1 to 4 As shown, the construction method of the anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to an embodiment of the present invention is applied to a slope, the surface of the slope is the existing ground line 10, the surface layer of the slope is a strongly weathered rock layer 20, and below the strongly weathered rock layer 20 is a moderately weathered rock layer 30, comprising:

[0037] Step 1: clean the slope surface of the fill slope, determine the positions of multiple anti-slide piles according to the design coordinates of the anti-slide piles, and excavate at the pile foundation positions;

[0038] Step 2: First, tie the steel bars and formwork of the anti-slide piles at the pile foundation position, tie the steel bars and formwork of the retaining plate between adjacent anti-slide piles, and pour concrete in sections to form the anti-slide piles and retaining plate;

[0039] Step 3: Backfill gravel into the trough formed by the retaining plate and two adjacent anti-slide piles, backfill soil behind the anti-slide piles, and evenly distribute multiple prestressed anchor cables along the upper and lower directions of the anti-slide piles. When the backfill soil is compacted to 2m above the anchor head of the first anchor cable at the bottom, perform anchor cable drilling and grouting construction. After the strength of the anchor section of a single anchor cable meets the design requirements, prestress tension and lock it. After tensioning is completed, continue to backfill to 2m above the anchor head of the second prestressed anchor cable, tension and lock it again, and repeat the above steps to complete tensioning of all anchor cables;

[0040] Step 4: After the filling below the pile top is completed according to the design requirements, check the standard value and locking value of the axial force of each prestressed anchor cable, and perform secondary tensioning and locking to eliminate the influence of pile displacement during pile foundation construction;

[0041] Step 5: Tie steel bars and pour concrete on the top of the anti-slide piles to form a continuous beam and a joist;

[0042] Step 6: Cast the counterweight retaining wall on the joists.

[0043] like Figures 2 to 4 As shown, the anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to the embodiment of the present invention is applied to a slope, the surface of the slope is the existing ground line 10, the surface layer of the slope is a strongly weathered rock layer 20, and below the strongly weathered rock layer 20 is a medium weathered rock layer 30, including: a plurality of anti-sliding piles 110, the plurality of anti-sliding piles 110 are evenly distributed on the slope along the front-back direction, and the lower end of each anti-sliding pile 110 is penetrated into the medium weathered rock layer 30; a prestressed anchor cable 120, one end of the prestressed anchor cable 120 is anchored on the anti-sliding pile 110, and the prestressed anchor cable 120 is The other end is embedded in the medium-weathered rock layer 30, and the prestressed anchor cable 120 is set at an angle; the retaining plate 130, the retaining plate 130 is set between two adjacent anti-slip piles 110, and the retaining plate 130 and the two adjacent anti-slip piles 110 together form a trough body for accommodating gravel 180; the supporting beam 140, the supporting beam 140 is set at the top of the anti-slip pile 110, and a counter-weight retaining wall 150 is set on the upper end of the supporting beam 140, and the counter-weight retaining wall 150, the retaining plate 130, the anti-slip pile 110 and the existing ground line 10 together form a backfill area 170.

[0044] In order to solve the problem of high fill slope reinforcement engineering with limited construction site, insufficient foundation bearing capacity and poor force of anti-sliding piles 110. This anchor-pull anti-sliding pile foundation beam retaining wall composite structure transfers the load on the retaining wall to the anti-sliding pile 110 through the beam 140, and then transfers the upper load to the stable rock and soil through the prestressed anchor cable 120. The overall structure is jointly stressed and deformed in a coordinated manner, thereby improving safety; the structure also has the structural characteristics of anti-sliding piles 110, retaining walls, and pile-board walls, and can effectively solve the overall stability problem in high fill slope support engineering. It not only provides sufficient foundation bearing capacity for the upper retaining wall, but also greatly reduces the design height and width of the counterweight retaining wall. The load on the retaining wall is transferred to the anti-sliding pile 110 through the beam 140, and then the upper load is transferred to the stable rock and soil through the prestressed anchor cable 120. It has reasonable force, ingenious design, safety and reliability, and is suitable for high fill slope support engineering.

[0045] like Figures 1 to 4 As shown, in the anchor-pull anti-sliding pile foundation beam retaining wall composite structure, multiple anti-sliding piles 110 are connected by a continuous beam 160, and the continuous beam 160 is arranged at the top of the anti-sliding pile 110. The anti-sliding pile 110 is a C30 reinforced concrete structure. The spacing between adjacent anti-sliding piles 110 is 4.5m to 5m. Specifically, the anti-sliding pile 110 adopts a cast-in-place C30 reinforced concrete structure. When the height difference of the fill slope is greater than 15m, the cross-section of the anti-sliding pile 110 is a rectangular cross-section of 180cm×280cm, and when the height difference of the fill slope is less than or equal to 15m, the cross-section of the anti-sliding pile 110 is a rectangular cross-section of 150cm×250cm; when the height difference of the fill slope is greater than 12m, the adjacent spacing is 4.5m, and when the height difference of the fill slope is less than or equal to 12m, the spacing of the anti-sliding piles 110 is 5m, and the gaps between adjacent anti-sliding piles 110 are filled with gravel 180 to meet the drainage requirements. A continuous beam 160 is arranged between adjacent anti-slide piles 110. The depth of the anti-slide piles 110 embedded in the strongly weathered rock layer 20 is greater than or equal to 8 m, and the depth of the anti-slide piles 110 embedded in the moderately weathered rock layer 30 is greater than or equal to 1 m. The continuous beam 160 adopts a cast-in-place C30 reinforced concrete structure with a rectangular cross section of 100 cm×150 cm, and is arranged between the anti-slide piles 110 to enhance the overall stability of the anti-slide piles 110.

[0046] like Figures 2 to 4 As shown, the prestressed anchor cable 120 includes a steel strand 121, one end of which is provided with an anchor pier 122, the steel strand 121 is fixed to the anti-sliding pile 110 through the anchor pier 122, and the other end of the steel strand 121 is an anchoring section 123, which is embedded in the medium weathered rock layer 30. The inclination angle of the prestressed anchor cable 120 is 20°, and the anchoring section 123 of the prestressed anchor cable 120 is embedded in the medium weathered rock layer 30 for a length of 7m.

[0047] like Figure 2 and Figure 3 As shown, the retaining plate 130 is a cast-in-place C30 reinforced concrete structure, and the depth of the retaining plate 130 embedded in the strongly weathered rock layer 20 is greater than or equal to 1m. The retaining plate 130 adopts a cast-in-place C30 reinforced concrete structure with a width of 40cm, which can improve the integrity of the structure and jointly bear the lateral earth pressure. A drainage pipe is arranged in the vertical direction on the retaining plate 130, and a drainage hole is opened on the drainage plate.

[0048] like Figure 2 As shown, the support beam 140 is arranged on the top of the anti-sliding pile 110, and adopts a cast-in-place C30 reinforced concrete structure with a rectangular cross-section of 290cm×40cm. The main reinforcement of the anti-sliding pile 110 extends into the support beam 140 to form an integral structure, which can effectively bear the upper load transmitted from the upper counterweight retaining wall.

[0049] like Figure 2 As shown, the counterweight retaining wall adopts C25 rubble concrete structure. The height of the counterweight retaining wall is 6m and it is placed on the support beam 140. The wall body is equipped with several drainage pipes. Behind the counterweight retaining wall is the backfill area 170, which is backfilled from the existing ground line 10 to the site design line.

[0050] The following is a specific construction example to illustrate the anchor-pull type anti-sliding pile foundation beam retaining wall composite structure:

[0051] ① Site clearing, leveling and foundation excavation:

[0052] While clearing and leveling the fill slope surface, surface interception, drainage and waterproofing work should be done well; the position of the anti-sliding pile 110 is determined according to the pile number and coordinates, and the pile well is excavated with a water-grinding drill according to the pile foundation position and the concrete retaining wall is poured simultaneously.

[0053] ② Construction of anti-slide piles 110 and retaining plates 130:

[0054] The anti-slide piles 110 and the retaining plate 130 are first reinforced and formworked, and then the concrete is poured in sections. During the pouring process, attention should be paid to measures such as reserved holes.

[0055] ③ Backfill gravel 180 between piles, backfill soil behind piles, drill holes for prestressed anchor cables 120 and tension and lock:

[0056] Backfill 180 of crushed stone between piles, and backfill behind piles should be implemented after the strength of pile body meets the requirements. Backfill soil is compacted layer by layer, each layer is 30cm, and the compaction degree of each layer is required to be ≥90%. Drainage pipes are set up after backfilling 180 of crushed stone between piles, and the backfill behind piles is compacted to an elevation of about 2m above the anchor head of the first anchor cable, and anchor cable drilling and grouting construction is carried out. After the strength of anchor section 123 of a single anchor cable meets the design requirements, prestressed tensioning and locking are carried out according to design requirements. After tensioning is completed, continue to backfill to an elevation of about 2m above the anchor head of the second prestressed anchor cable 120, tension and lock again, and repeat the above steps until backfilling to the pile top elevation and tensioning of the nth prestressed anchor cable 120 is completed.

[0057] ④After the filling construction below the pile top is completed, the prestressed anchor cable 120 is tensioned for the second time:

[0058] After the backfill below the pile top is constructed as per the design requirements, check the 120° axial force standard value and locking value of each prestressed anchor cable, and perform secondary tensioning and locking as per the design requirements to eliminate the impact of pile displacement during the pile foundation construction process.

[0059] ⑤ Construction of continuous beam 160 and joist 140 on piles:

[0060] The continuous beam 160 on the pile and the supporting beam 140 are successively reinforced and concreted.

[0061] ⑥ Casting counterweight retaining wall:

[0062] After all the anti-sliding piles 110, continuous beams 160 and joists 140 are constructed and reach the design strength requirements, the counterweight retaining wall on the joist 140 is constructed. Effective measures are taken during the pouring process to avoid cracking of large-volume concrete, and the integrity of the retaining wall should be ensured during the multiple pouring.

[0063] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. An anchor-pull type anti-sliding pile foundation beam retaining wall composite structure, applied to a slope, the surface of the slope is the existing ground line (10), the surface layer of the slope is a strongly weathered rock layer (20), and below the strongly weathered rock layer (20) is a moderately weathered rock layer (30), characterized in that: include: A plurality of anti-slip piles (110), wherein the plurality of anti-slip piles (110) are evenly distributed on the slope along the front-rear direction, and the lower end of each anti-slip pile (110) is penetrated into the medium-weathered rock layer (30); A prestressed anchor cable (120), one end of the prestressed anchor cable (120) being anchored on the anti-sliding pile (110), the other end of the prestressed anchor cable (120) being embedded in the medium-weathered rock layer (30), and the prestressed anchor cable (120) being arranged at an angle; A retaining plate (130), wherein the retaining plate (130) is arranged between two adjacent anti-sliding piles (110), and the retaining plate (130) and the two adjacent anti-sliding piles (110) together form a trough body for accommodating gravel (180); A support beam (140), wherein the support beam (140) is arranged at the top of the anti-sliding pile (110), and a counterweight retaining wall (150) is arranged at the upper end of the support beam (140), and the counterweight retaining wall (150), the retaining plate (130), the anti-sliding pile (110) and the existing ground line (10) together form a backfill area (170).

2. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 1 is characterized in that: A plurality of the anti-slip piles (110) are connected by a continuous beam (160), and the continuous beam (160) is arranged at the top of the anti-slip pile (110).

3. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 2 is characterized in that: The anti-sliding pile (110) is a C30 reinforced concrete structure.

4. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 3 is characterized in that: The distance between adjacent anti-slip piles (110) is 4.5m to 5m.

5. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 4 is characterized in that: The anti-sliding pile (110) is embedded in the strongly weathered rock layer (20) to a depth greater than or equal to 8 m, and the anti-sliding pile (110) is embedded in the moderately weathered rock layer (30) to a depth greater than or equal to 1 m.

6. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 1 is characterized in that: The prestressed anchor cable (120) comprises a steel strand (121), one end of which is provided with an anchor pier (122), the steel strand (121) is fixed to the anti-sliding pile (110) via the anchor pier (122), and the other end of the steel strand (121) is an anchoring section (123), and the anchoring section (123) is embedded in the medium-weathered rock layer (30).

7. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 1 is characterized in that: The retaining plate (130) is a cast-in-place C30 reinforced concrete structure, and the retaining plate (130) is embedded in the strongly weathered rock layer (20) to a depth greater than or equal to 1 m.

8. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 7 is characterized in that: A drainage pipe is arranged on the retaining plate (130) in the vertical direction, and a drainage hole is opened on the drainage plate.

9. The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 1, characterized in that: The joist (140) is a cast-in-place C30 reinforced concrete structure, and the main reinforcement of the anti-sliding pile (110) extends into the joist (140) to form an integral structure.

10. A construction method of an anchor-pull type anti-sliding pile foundation beam retaining wall composite structure, characterized in that: The anchor-pull type anti-sliding pile foundation beam retaining wall composite structure is the anchor-pull type anti-sliding pile foundation beam retaining wall composite structure according to claim 1, and the construction method comprises: Step 1: clean the slope surface of the fill slope, determine the positions of multiple anti-slide piles according to the design coordinates of the anti-slide piles, and excavate at the pile foundation positions; Step 2: First, tie the steel bars and formwork of the anti-slide piles at the pile foundation position, tie the steel bars and formwork of the retaining plate between adjacent anti-slide piles, and pour concrete in sections to form the anti-slide piles and retaining plate; Step 3: Backfill gravel into the trough formed by the retaining plate and two adjacent anti-slide piles, backfill soil behind the anti-slide piles, and evenly distribute multiple prestressed anchor cables along the upper and lower directions of the anti-slide piles. When the backfill soil is compacted to 2m above the anchor head of the first anchor cable at the bottom, perform anchor cable drilling and grouting construction. After the strength of the anchor section of a single anchor cable meets the design requirements, prestress tension and lock it. After tensioning is completed, continue to backfill to 2m above the anchor head of the second prestressed anchor cable, tension and lock it again, and repeat the above steps to complete tensioning of all anchor cables; Step 4: After the filling below the pile top is completed according to the design requirements, check the standard value and locking value of the axial force of each prestressed anchor cable, and perform secondary tensioning and locking to eliminate the influence of pile displacement during pile foundation construction; Step 5: Tie steel bars and pour concrete on the top of the anti-slide piles to form a continuous beam and a joist; Step 6: Cast the counterweight retaining wall on the joists.

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