Construction method of rectangular anti-slide pile mechanical hole forming

Abstract

This invention discloses a construction method for mechanically drilling rectangular anti-slide piles, which can reduce the installation difficulty of rectangular anti-slide piles and precast retaining plates, and improve installation efficiency, installation quality and installation safety. The construction method includes: construction preparation; surveying and setting out; lock construction; mechanical drilling, marking area one and area two in the middle of the lock opening, marking area three on the left and right sides of the first side of the opening, marking area four between area one, area two and the third side of the opening, marking area four between area one, area two and the fourth side of the opening, installing a circular drill bit on a rotary drilling rig, drilling circular holes in area one and area two until the designed bottom of the hole, replacing the circular drill bit with a rectangular drill bit of the same size as area three, drilling in area three to the designed depth, and using the rectangular drill bit to finish the hole in area four to the designed bottom of the hole; reinforcement cage construction; installing pre-embedded reinforcing bars and end cap templates on the corresponding segment of the reinforcement cage; tremie pipe installation and concrete pouring, etc.

Description

Technical Field

[0001] This invention relates to the field of slope protection technology, and in particular to a construction method for mechanically drilling rectangular anti-slide piles. Background Technology

[0002] In construction projects such as roads and bridges, slope protection is often involved. To prevent landslides and improve slope stability and safety, anti-slide piles are typically added to the slope protection system. These piles support the landslide mass, transferring its lateral force to stable soil and rock, thus stabilizing the slope. In situations where the landslide mass is a loose medium (such as gravelly soil, silty clay, or sandy gravel), the soil between the piles is unstable, or the slope is steep (at least 20m high), retaining walls are often installed between the anti-slide piles to bear the lateral earth pressure and prevent soil collapse.

[0003] Anti-slide piles are classified into rectangular and circular anti-slide piles according to their cross-sections. Rectangular anti-slide piles have greater bending stiffness than circular anti-slide piles of the same area. Rectangular anti-slide piles are usually excavated manually or mechanically. Manual excavation of bored piles has a high incidence of collapse accidents and is inefficient and costly, and its use is being gradually restricted and phased out. Mechanical excavation usually uses a rotary drilling rig with a circular drill bit to drill multiple times to form an approximately rectangular hole, and then uses a hammer to cut the hole wall and remove excess soil. This method has high site requirements, is difficult to trim in hard rock strata, is not easy to control the pile size, and has poor surface flatness.

[0004] When constructing existing anti-slide piles and retaining slabs, the retaining slabs are usually constructed using either cast-in-place or precast methods. Cast-in-place construction involves complex on-site formwork construction, poor assembly quality, and low work efficiency. The anchoring reinforcement between the pile and the retaining slab is also complex and cannot guarantee construction quality. Precast construction typically involves setting grooves on the anti-slide piles and setting structures on the retaining slabs that match the grooves, allowing the retaining slabs and the grooves on the anti-slide piles to connect. In this construction method, the anti-slide piles and the groove connection structure on the anti-slide piles are complex, and the construction of anti-slide piles with grooves is difficult.

[0005] Therefore, in the construction of rectangular anti-slide piles and retaining slabs, the key issues are how to design and construct the pile holes for rectangular anti-slide piles, how to improve the installation efficiency and quality of rectangular anti-slide piles and precast retaining slabs, how to reduce the installation difficulty and ensure construction safety. Summary of the Invention

[0006] One of the objectives of this invention is, at least, to provide a construction method for mechanically drilling rectangular anti-slide piles, which addresses the problems existing in the prior art and can reduce the installation difficulty of rectangular anti-slide piles and precast retaining plates, thereby improving installation efficiency, installation quality, and installation safety.

[0007] To achieve the above objectives, the technical solution adopted by the present invention includes the following aspects.

[0008] A construction method for mechanically drilling rectangular anti-slide piles includes: S101. Construction preparation: Level the site, remove loose soil from the slope, excavate and compact the loose soil layer in the site. S102. Surveying and setting out; re-measure the construction control elevation, water level point, measure the ground elevation of the pile hole, level the site to the top elevation of the pile, and calculate the excavation depth; mark the perimeter of the pile using white lime lines according to the cross lines of the pile position. S103, Lock construction; construct the lock within the marked pile perimeter boundary, with the central section of the lock having a rectangular cross-section; S104, Mechanical drilling; Mark the excavation area inside the opening of the lock, mark area one and area two in the middle area of ​​the opening, mark area three on the left and right sides of the first side of the opening respectively, mark area four between area one, area two and the third side of the opening, and mark area four between area one, area two and the fourth side of the opening. Install a circular drill bit on a rotary drilling rig and construct circular holes in Area 1 and Area 2 respectively until the bottom of the designed hole is reached. Replace the round drill bit with a rectangular drill bit that matches the dimensions of area three, and drill a hole in area three to the designed depth. Repair the hole in area four to the bottom of the designed hole; S105, Reinforcing cage construction: Divide the reinforcing cage of the rectangular anti-slide pile into multiple sections, connect the reinforcing cages of adjacent sections in sequence and lower them into the pile hole. According to the design installation depth requirements of the retaining plate, install the pre-embedded reinforcing bars and end cap templates on the corresponding sections of the reinforcing cage. S106. Conduit installation: The conduit is hoisted using hoisting equipment. During the lowering of the conduit into the reinforcing cage, the conduit is positioned at the center of the borehole. The conduit is hoisted and extended section by section and lowered vertically. S107, Concrete pouring.

[0009] Preferably, in step S105, when the reinforcing cage is divided into two sections, the first section of the reinforcing cage is located at the bottom of the hole, and the second section of the reinforcing cage is connected to the first section and located on top of the first section. When manufacturing the second section of the reinforcing cage, two sets of pre-embedded reinforcing bars are fixed on one side of the reinforcing cage near the opening. The two sets of pre-embedded reinforcing bars are respectively set close to the left and right sides of the reinforcing cage. Each set of pre-embedded reinforcing bars includes multiple pre-embedded reinforcing bars, which are evenly arranged along the height direction of the reinforcing cage. Then, a capping template is installed on one side of the reinforcing cage near the opening. The capping template is installed on the outside of the reinforcing cage, and multiple capping templates are arranged along the height direction of the reinforcing cage.

[0010] Preferably, when installing the end cap template, holes are made in the end cap template at the positions of the pre-embedded reinforcing bars corresponding to the reinforcing cage, so that the pre-embedded reinforcing bars pass through the end cap template, and the pre-embedded reinforcing bars and the end cap template are connected. The end cap template and the reinforcing cage are supported by protective layer spacers.

[0011] Preferably, after the end cap template is installed, galvanized wire mesh is connected to the left and right sides of the end cap template respectively, and rivets are used to connect the galvanized wire mesh and the end cap template at certain intervals along the height direction of the end cap template.

[0012] Preferably, when installing the second section of the reinforcing cage, the second section of the reinforcing cage is hoisted above the first section of the reinforcing cage at the borehole opening. The position of the second section of the reinforcing cage is adjusted so that the end cap template is aligned with the first side of the opening of the lock, and the lower part of the second section of the reinforcing cage is aligned with the top of the first section of the reinforcing cage. After connecting the first section of the reinforcing cage and the second section of the reinforcing cage with a threaded sleeve, the first and second sections of the reinforcing cage are lowered together, so that the first section of the reinforcing cage is lowered to the bottom of the borehole. The end cap template on the second section of the reinforcing cage closes the side of the rectangular hole in area three. The pre-embedded reinforcing bars on the second section of the reinforcing cage extend out of the end cap template and are located in the rectangular hole in area three. The galvanized wire mesh on both sides of the end cap template seals the gap between the end cap template and the pile hole wall.

[0013] Preferably, after the steel cage is installed, fine-grained soil is backfilled into the rectangular hole formed by the excavation in area three.

[0014] Furthermore, the width d of the rectangular hole formed by the third excavation in area 3 shall not be less than the thickness of the retaining plate, and the length of the rectangular hole formed by the third excavation in area 3 shall not be less than the width d. The specific length shall be determined according to the design and construction requirements.

[0015] Preferably, after constructing a row of rectangular anti-slide piles using the aforementioned mechanical drilling method, retaining wall construction is carried out, which includes the following steps: S201. Mechanically excavate the soil between the piles on the outer side of the rectangular anti-slide piles, with the excavation depth being the first depth. S202. Install multiple retaining plates from top to bottom between two adjacent rectangular anti-slide piles to the first depth; S203. Determine whether the cumulative first excavation depth of the soil between piles has reached the design depth. If yes, end the excavation of the soil between piles and the installation of the retaining plate. If not, repeat S201 and S202 until the cumulative excavation depth of the soil between piles reaches the design depth and the cumulative installation depth of the retaining plate reaches the design depth.

[0016] Preferably, in step S201, when the excavation reaches the location of the rectangular anti-slide pile, the soil between area three is removed to expose the end cap template, and then the end cap template is removed from the rectangular anti-slide pile.

[0017] Preferably, the retaining plate has a rectangular cross-section and is provided with mounting through holes. The mounting through holes are respectively located near the left and right surfaces of the retaining plate and penetrate the retaining plate through the thickness direction. The retaining plate is also provided with a recessed mounting groove, which is coaxially arranged with the mounting through holes. The mounting groove is recessed on the front side of the retaining plate and is provided with a steel pad at the bottom of the mounting groove.

[0018] Preferably, the installation process of a single retaining plate includes: Position the retaining plate between two adjacent rectangular anti-slide piles, and align the installation through hole of the retaining plate with the pre-embedded steel bars on the rectangular anti-slide piles; Push the retaining plate so that the pre-embedded steel bars pass through the installation through holes and steel pads on the retaining plate, and after the rear side of the retaining plate contacts the surface of the rectangular anti-slide pile, use steel bar welding to limit and fix it. C35 fine aggregate concrete was used to seal the anchors in the installation slots of the retaining plate.

[0019] In summary, by adopting the above technical solution, the present invention has at least the following beneficial effects: During the excavation of the pile hole, the cross-section of the lock is marked as rectangular, and areas one to four are marked. Areas one and two are located in the middle of the opening and are circular areas. The two areas three are located on the left and right sides of the first side of the opening, respectively. The other areas are designated as area four. Areas three and four are rectangular areas. For areas one and two, a circular rotary drill bit is used for construction. For area four, a rectangular drill bit with the same size as the rectangular anti-slide pile is used to mill the pile body. This ensures the pile size and the flatness of the pile surface, and guarantees the quality of the rectangular anti-slide pile hole.

[0020] Area 3 has a rectangular cross-section, as do the pile holes formed by Areas 1, 2, and 4. Areas 1, 2, and 4 are excavated to the designed bottom of the hole, while Area 3 serves as a protruding portion. The protruding width d of Area 3 is not less than the thickness of the retaining plate, and the excavation depth corresponds to the installation depth of the retaining plate, which is less than the designed bottom depth of the hole. By excavating Area 3, when installing the reinforcing cage in the pile holes formed by Areas 1, 2, and 4, the pre-embedded reinforcing bars on the cage extend horizontally into the rectangular hole formed by Area 3. The length of the pre-embedded reinforcing bars extending into the rectangular hole of Area 3 meets the installation requirements of the retaining wall. After the rectangular anti-slide piles in Areas 1, 2, and 4 are formed, the pre-embedded reinforcing bars extend out of the rectangular anti-slide piles to connect with the retaining plate. This reduces the connection difficulty between the rectangular anti-slide piles and the retaining plate without damaging the structure of the rectangular anti-slide piles, thus improving installation efficiency, quality, and safety.

[0021] During the manufacturing of the reinforcing cage, pre-embedded reinforcing bars and end-cap templates are constructed in the segmental construction corresponding to the retaining plate along the height direction of the reinforcing cage. The end-cap templates are connected to the pre-embedded reinforcing bars. After the reinforcing cage is placed into the pile hole, the end-cap templates seal the sides of the rectangular hole formed in Zone 3, thereby preventing the anti-slide pile concrete from flowing into the rectangular hole formed in Zone 3. When installing the retaining plate later, it is only necessary to excavate the soil between the two Zone 3s (if the rectangular hole formed in Zone 3 is filled with soil, the filling soil is also excavated), which further reduces the installation difficulty of the rectangular anti-slide piles and retaining plates and improves construction efficiency. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the mechanical drilling process for rectangular anti-slide piles, an exemplary embodiment of the present invention.

[0023] Figure 2 This is a flowchart illustrating the construction process of retaining walls according to an exemplary embodiment of the present invention.

[0024] Figure 3 This is a plan view of the lock opening of an exemplary embodiment of the present invention.

[0025] Figure 4 This is an elevation view of the lock opening of an exemplary embodiment of the present invention.

[0026] Figure 5 This is a marking diagram of the excavation area of ​​a rectangular anti-slide pile according to an exemplary embodiment of the present invention.

[0027] Figure 6 This is a plan view of the rectangular anti-slide pile after the steel cage is installed, according to an exemplary embodiment of the present invention.

[0028] Figure 7 This is an elevation view of the end cap template connection according to an exemplary embodiment of the present invention.

[0029] Figure 8 This is an elevation view of a retaining plate according to an exemplary embodiment of the present invention.

[0030] Figure 9 This is a plan view of a retaining plate according to an exemplary embodiment of the present invention.

[0031] Figure 10 This is a side view of the rectangular anti-slide pile and retaining plate after connection, according to an exemplary embodiment of the present invention.

[0032] Figure 11 This is an elevation view of the rectangular anti-slide pile and retaining plate after connection, according to an exemplary embodiment of the present invention.

[0033] Figure 12 This is a schematic diagram of the connection between a rectangular anti-slide pile and a retaining plate in an exemplary embodiment of the present invention.

[0034] Figure 13This is an enlarged schematic diagram of the retaining plate connection part of an exemplary embodiment of the present invention.

[0035] Figure 14 This is a schematic diagram of the rebar connection of an exemplary embodiment of the present invention.

[0036] The diagram is labeled as follows: 1-Area 1, 2-Area 2, 3-Area 3, 4-Area 4, 5-Lock, 500-Mouth, 5001-First side of mouth, 5002-Second side of mouth, 5003-Third side of mouth, 5004-Fourth side of mouth, 501-Lock steel frame, 6-Wall protection, 600-Wall protection steel frame, 7-Reinforcing cage, 8-Embedded reinforcing bars, 9-End template, 10-Galvanized wire mesh, 11-Rectangular anti-slide pile, 12-Retaining plate, 1201-Front side, 1202-Rear side, 1203-Left side, 1204-Right side, 120-Installation through hole, 121-Installation groove, 122-Drainage hole, 124-Retaining plate steel frame, 13-Steel pad, 14-Reinforcing bar, 15-Weld. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so that the objectives, technical solutions, and advantages of the present invention will be clearer. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0038] refer to Figure 1 The construction method for mechanically drilling rectangular anti-slide piles according to an exemplary embodiment of the present invention includes the following steps: S101. Construction preparation: Level the site, remove loose soil from the slope, excavate and compact the soft soil layer in the site; repair the muck removal access road to ensure that the access road is flat, firm and free of water accumulation, and transport the drilling muck in the site to the corresponding spoil disposal site to avoid affecting the construction in the site.

[0039] S102. Surveying and setting out; re-measure the construction control elevation, water level point, measure the ground elevation of the pile hole, level the site to the top elevation of the pile, and calculate the excavation depth; mark the perimeter of the pile with white lime lines according to the cross lines of the pile position to clarify the construction scope.

[0040] S103, Lock construction; construct lock 5 within the marked pile perimeter boundary (e.g. Figure 3 As shown), lock 5 is a grid-beam lock. The opening 500 in the middle of lock 5 has a rectangular cross section. When the soil is complex and has poor integrity, the grid-beam lock can prevent lock 5 from sagging and deforming, and prevent the pile opening of the rectangular anti-slide pile from collapsing. Lock 5 is a steel-concrete structure. Lock 5 has a lock steel skeleton 501 inside. The main reinforcement of lock steel skeleton 501 is made of Φ14 threaded steel, the stirrups are made of Φ14 threaded steel, and the lock concrete grade is C25.

[0041] S104, Mechanical Drilling; The pile holes for rectangular anti-slide piles are constructed using rotary drilling rigs. The construction process for the pile holes of rectangular anti-slide piles includes: marking the excavation area within the opening 500 of the lock 5; marking Region 1 and Region 2 in the middle area of ​​the opening 500, where Region 1 and Region 2 are circular areas and tangent to each other; marking Region 3 on the left and right sides of the first side 5001 of the opening, where Region 3 is a rectangular area; marking Region 4 between Region 1, Region 2, and the third side 5003 of the opening; and marking Region 4 between Region 1, Region 2, and the fourth side 5004 of the opening (see reference). Figure 3 , Figure 5 Since the cross-section of the opening 500 is rectangular, the first side 5001 to the fourth side 5004 of the opening are the sides formed by the projections of the four sides of the opening 500. The first side 5001 and the second side 5002 of the opening are opposite each other, and the third side 5003 and the fourth side 5004 of the opening are opposite each other.

[0042] Install a 150cm diameter circular drill bit on the rotary drilling rig and drill 150cm diameter circular holes in Area 1 and Area 2 (the construction order of Area 1 and Area 2 can be interchanged) until the designed bottom of the hole. Replace the circular drill bit with a rectangular drill bit of the same size as Area 3 and drill a hole in Area 3 to the designed depth (the installation depth of the retaining plate, such as 8m or 10m, the specific depth is determined according to actual requirements). Then, repair the hole in Area 4 to the designed bottom of the hole. The slag from milling the pile body with the rectangular drill bit is removed by secondary cleaning using the rotary drilling rig.

[0043] During mechanical drilling, the central circular hole (region 1 and region 2) is excavated first, which can quickly penetrate the soil / rock layer to the bottom of the hole. Excavating the central circular hole mainly releases the stress of the central soil. The soil around the central circular hole is still in a ring support state, and the stress release is stable. When milling the pile body later, only the corner margin between the circular hole and the rectangular hole is excavated in a small amount, which hardly disturbs the main structure of the rectangular hole wall. The overall stress state of the rectangular hole wall is not destroyed, which can significantly reduce the risk of hole collapse and improve the quality of drilling. After excavating the central circular hole, two rectangular holes are first excavated on the left and right sides of the first side of the opening, forming area 3. Then, area 4 is excavated. The depth of the rectangular holes in area 3 is less than the depth of the pile holes of the rectangular anti-slide piles. The rectangular holes formed in area 3 facilitate the pre-embedding of the connection structure of the retaining plate underground. The connection structure of the retaining plate is constructed together with the construction of the rectangular anti-slide piles. When connecting the retaining plate later, it is not necessary to damage the structure of the rectangular anti-slide piles. The rectangular anti-slide piles provide a connection foundation for the connection of the retaining plate, ensuring the integrity and stability of the connection between the rectangular anti-slide piles and the retaining plate, thereby improving the slope protection effect.

[0044] During mechanical drilling, a geological check is conducted every 1 meter of drilling by the rotary drilling rig. A sample of the drilling slag is left on site to check whether the drilling slag is consistent with the design drawings. If it is inconsistent with the design drawings, the relevant unit is contacted for handling. If it is consistent with the design drawings, drilling continues to the design elevation. If groundwater seepage is encountered during drilling, a submersible pump is used to pump out the groundwater. When the pile hole is excavated to the design bottom elevation, a hole cleaning operation is carried out to clean the floating slag at the bottom of the hole. The pile bottom elevation is checked using the rope hoisting method, and the pile bottom elevation is determined according to the top surface elevation of the interlock and the pile length.

[0045] During the hole repair process in area 4, a retaining wall 6 can also be constructed below the locking joint 5 to protect the pile hole wall after repair. The retaining wall 6 is equipped with a retaining wall steel frame 600 (reference). Figure 4 The retaining wall 6 can further prevent the pile hole of the rectangular anti-slide pile from collapsing.

[0046] S105, Reinforcing Cage Construction; According to the design drawings, the reinforcing cage 7 of the rectangular anti-slide pile is divided into multiple sections (the length of each section is determined according to the design requirements). In this embodiment, the reinforcing cage 7 is divided into two sections, each with a length of 10-15m. Each section of the reinforcing cage is cut and formed at the reinforcing bar processing plant and transported to the construction site. The first section of the reinforcing cage is located at the bottom of the hole, and the second section of the reinforcing cage is connected to the first section and located on top of the first section. For the second section of the reinforcing cage, according to the design requirements, two sets of pre-embedded reinforcing bars are fixed on one side of the first side 5001 near the opening of the reinforcing cage 7. The two sets of pre-embedded reinforcing bars are respectively set near the left and right sides of the reinforcing cage 7 (the specific positions are determined according to the design requirements). Each set of pre-embedded reinforcing bars includes multiple pre-embedded reinforcing bars 8, which are evenly arranged along the height direction of the reinforcing cage 7. The spacing between adjacent pre-embedded reinforcing bars 8 is determined according to the design requirements. Then, on the first side 5001 near the opening of the reinforcing cage 7... One side of the 01 is equipped with a head template 9, which is installed on the outside of the reinforcing cage 7. Multiple head templates 9 are set along the height direction of the reinforcing cage 7 to seal the gaps between adjacent head templates 9 to prevent grout leakage during subsequent concrete pouring. When installing the head template 9, holes are made at the positions of the pre-embedded reinforcing bars 8 in the reinforcing cage 7 on the head template 9 so that the pre-embedded reinforcing bars 8 can pass through the head template 9. The pre-embedded reinforcing bars 8 and the head template 9 are then connected (threads can be set on the pre-embedded reinforcing bars, and nuts can be screwed into the pre-embedded reinforcing bars after they pass through the head template; the pre-embedded reinforcing bars can also pass directly through the head template 9). There is a certain distance between the head template 9 and the reinforcing cage 7. Protective layer spacers can be set between the head template 9 and the reinforcing cage 7 as supports to prevent the head template 9 from tilting to one side of the reinforcing cage 7, which would affect the pile body size of the rectangular anti-slide pile. The protective layer spacers can also ensure that the protective layer thickness of the rectangular anti-slide pile meets the requirements. After the end cap template 9 is installed, galvanized wire mesh 10 is connected to both sides of the end cap template 9. Along the height of the end cap template 9, at regular intervals (e.g., 10cm~50cm), the galvanized wire mesh 10 is connected to the end cap template 9 using rivets. (Refer to...) Figure 6 , Figure 7 .

[0047] When installing the reinforcing cage 7 in the pile hole of the rectangular anti-slide pile, the first section of the reinforcing cage is hoisted to the hole opening and aligned with the center of the pile hole using a crane. The first section of the reinforcing cage is then lowered until the upper stiffening hoop protrudes from the hole opening to facilitate connection with the second section of the reinforcing cage. The second section of the reinforcing cage is then hoisted above the first section of the reinforcing cage at the hole opening. The position of the second section of the reinforcing cage is adjusted so that the end cap template 9 is aligned with the first side 5001 of the opening of the locking joint 5, and the lower part of the second section of the reinforcing cage is aligned with the top of the first section of the reinforcing cage. After connecting the first and second sections of the reinforcing cage with threaded sleeves, the first and second sections of the reinforcing cage are lowered together, with the first section reaching the bottom of the hole. After the first and second sections of the reinforcing cage are lowered, the end cap template 9 on the second section of the reinforcing cage closes the side of the rectangular hole in area 3. The pre-embedded reinforcing bars 8 on the second section of the reinforcing cage extend from the end cap template 9 and are located in the rectangular hole in area 3. The galvanized wire mesh 10 on both sides of the end cap template 9 seals the gap between the end cap template 9 and the pile hole wall (see reference). Figure 6 The head template 9 can be made of bamboo plywood, wood board or polyboard, etc. After the steel cage 7 is installed, fine soil can be used to backfill the rectangular hole formed by the excavation of area 3 to avoid the head template 9 from slipping during the concrete pouring of the rectangular anti-slide pile, which would affect the pile body size and construction quality.

[0048] For the second section of the reinforcing cage, after the pre-embedded reinforcing bars 8 and the end-capping formwork 9 are lowered into the pile hole along with the second section of the reinforcing cage, the pre-embedded reinforcing bars 8 extend into the rectangular hole of area 3. The end-capping formwork 9 seals the side of the rectangular hole of area 3. After the rectangular anti-slide pile concrete is poured, the end-capping formwork 9 can prevent the anti-slide pile concrete from flowing into area 3, thus ensuring the appearance quality and dimensional requirements of the rectangular anti-slide pile. Since the end-capping formwork 9 prevents the anti-slide pile concrete from flowing into area 3, when constructing the retaining plate later, the soil around the rectangular anti-slide pile can be excavated, so that the retaining plate can be stably connected to the pre-embedded reinforcing bars 8 extending from the rectangular anti-slide pile. This reduces the installation difficulty of the rectangular anti-slide pile and the retaining plate without damaging the rectangular anti-slide pile structure. Figure 6The area between the two regions 3 is unexcavated soil. The area between the two regions 3 can provide support for the end cap formwork 9, so as to avoid the end cap formwork 9 shifting during the concrete pouring of the rectangular anti-slide pile, which would affect the construction quality of the rectangular anti-slide pile. The width of the end cap template 9 is smaller than the width between the third side 5003 and the fourth side 5004 of the opening, so that the end cap template 9 can be smoothly lowered into the pile hole along with the reinforcing cage 7. The galvanized wire mesh 10 on the left and right sides of the end cap template 9 can seal the gaps between the end cap template 9 and the third side 5003 and the fourth side 5004 of the opening, so as to prevent the concrete of the anti-slide pile from flowing into the third area 3 during the pouring process. The galvanized wire mesh 10 can be rolled up, so it can be lowered into the pile hole along with the end cap template 9 to seal the gap (3~5cm) between the end cap template 9 and the pile hole wall. By changing the mesh size of the galvanized wire mesh 10, the aggregate in the anti-slide pile concrete can be prevented from passing through the galvanized wire mesh, thereby ensuring the construction quality of the rectangular anti-slide pile. A small amount of mortar that passes through the galvanized wire mesh 10 can be removed during the subsequent installation of the retaining plate.

[0049] In the aforementioned process, when the reinforcing cage is divided into more sections, a crane is used to connect the adjacent sections of the reinforcing cage in sequence and lower them into the pile hole. The connection method between adjacent reinforcing cages is the same as the connection method between the first and second sections of the reinforcing cage, which is to use threaded sleeve connection. According to the design installation depth requirements of the retaining plate, the pre-embedded reinforcing bars and end cap templates are installed on the corresponding sections of the reinforcing cage.

[0050] S106. Conduit Installation: Use hoisting equipment (not limited to truck cranes, crawler cranes, cranes, etc., as long as they can meet the hoisting and installation requirements of the conduit) to hoist the conduit. During the lowering process in the reinforcing cage, ensure that the conduit is centered in the borehole to prevent the conduit joints from snagging on the reinforcing cage. The total length of the conduit and the combination of each section are determined according to the design requirements. Before lowering the conduit, check whether each conduit is clean, unobstructed, and the O-ring is intact. Hoist and extend the conduit section by section and lower it vertically. Lower the conduit until the bottom of the conduit is 30-40cm from the bottom of the borehole. To ensure the accuracy of the lowered length, first lower the conduit to the bottom of the borehole, then lift the conduit 40cm up for verification.

[0051] S107. Concrete pouring: Before concrete pouring, a sufficient number of concrete mixer trucks shall be configured according to the construction situation to ensure continuous pouring after the first batch of concrete is poured without interruption. During the pouring process, the height of the concrete surface shall be measured and recorded to calculate the depth of the tremie pipe embedded in the concrete. If the tremie pipe needs to be disassembled during the pouring process, the on-site technicians shall calculate and determine the disassembly length. The free fall height of the concrete shall not exceed 2m.

[0052] During the construction of rectangular anti-slide piles, each rectangular anti-slide pile is constructed using the methods described in S101~S107 above. When constructing a row of rectangular anti-slide piles, for the pre-defined area, the rectangular anti-slide piles are constructed using the skip-excavation method, dividing the rectangular anti-slide piles into two groups. The rectangular anti-slide piles of the second group are located between adjacent rectangular anti-slide piles of the first group. During construction, the first group of rectangular anti-slide piles is constructed first (the rectangular anti-slide piles of the first group can be constructed simultaneously or sequentially). When the concrete strength of the first group of rectangular anti-slide piles reaches 80% of the design grade, the second group of rectangular anti-slide piles is constructed between adjacent rectangular anti-slide piles of the first group. The cross-sectional dimensions of the rectangular anti-slide piles are determined according to the design requirements. For example, the length of the rectangular anti-slide pile is 3~5m, the width is 2~3m, and the depth is 20~35m. The distance between adjacent rectangular anti-slide piles meets the installation requirements of the retaining plate (the specific distance is determined according to the design requirements).

[0053] After constructing a row of rectangular anti-slide piles (at least two rectangular anti-slide piles) using the aforementioned method, construct retaining walls. The construction depth of the retaining walls should be less than the construction depth of the rectangular anti-slide piles, as per reference. Figure 2 The construction of retaining walls includes the following steps: S201. On the outer side of the rectangular anti-slide pile 11, the roadbed is mechanically excavated downwards between the piles to the first depth. When the excavation reaches the position of the rectangular anti-slide pile 11, the soil between area 3 is removed to expose the end cap template 9. Then, the end cap template 9 is removed from the rectangular anti-slide pile. When the end cap template is connected to galvanized wire mesh on both sides, the end cap template 9 and the galvanized wire mesh 10 are removed from the rectangular anti-slide pile together.

[0054] S202. Install retaining plates 12 between two adjacent rectangular anti-slide piles 11; the retaining plates 12 are prefabricated in the processing plant and transported to the construction site for installation; the retaining plates 12 can be made of C30 or higher grade concrete, see reference. Figure 8 The retaining plate 12 has a rectangular cross-section. It has mounting through holes 120 located near the left and right surfaces of the retaining plate 12, extending through its thickness. The retaining plate 12 also has a recessed mounting groove 121, coaxial with the mounting through holes 120. The mounting groove 121 is recessed into the front side 1201 of the retaining plate 12, with the front side 1201 and rear side 1202 of the retaining plate 12 facing each other. Figure 8 (Up and down direction), the left side 1203 and right side 1204 of the retaining plate 12 are opposite to each other ( Figure 8 (Left and right directions); a steel pad 13 is provided in the mounting slot 121 (for reference). Figure 8 , Figure 9The steel pad 13 is located at the bottom of the installation groove 121. The steel pad 13 can be pre-embedded in the installation groove 121 during the prefabrication of the retaining plate 12, or it can be placed in the installation groove 121 during the installation of the retaining plate 12. The retaining plate 12 is also provided with one or more drainage holes 122 in the thickness direction. After the retaining plate 12 is installed, the water in the soil can be discharged through the drainage holes 122 on the retaining plate 12 to avoid slope instability.

[0055] The installation process of a single retaining plate 12 includes: Position the retaining plate 12 between two adjacent rectangular anti-slide piles 11, and align the installation through hole of the retaining plate 12 with the pre-embedded steel bar 8 on the rectangular anti-slide pile.

[0056] Push the retaining plate 12 so that the pre-embedded reinforcing bar 8 passes through the installation through hole on the retaining plate 12 (when a steel pad is installed on the retaining plate, the pre-embedded reinforcing bar also passes through the steel pad), and after the rear side 1202 of the retaining plate 12 contacts the surface of the rectangular anti-slide pile 11, it is fixed by reinforcing bar welding; after the pre-embedded reinforcing bar 8 passes through the retaining plate 12, the end of the pre-embedded reinforcing bar 8 is located in the installation groove 121 of the retaining plate 12; during the welding process of the reinforcing bar, after the pre-embedded reinforcing bar 8 passes through the retaining plate 12 and the steel pad 13 on the retaining plate 12, the pre-embedded reinforcing bar 8 and the steel pad 13 are welded together, and then multiple reinforcing bar strips 14 are evenly welded circumferentially to the pre-embedded reinforcing bar 8, and each reinforcing bar strip 14 is welded to the steel pad 13 (refer to...). Figure 13 The steel reinforcement strip 14 connects the steel pad 13 and the embedded steel reinforcement 8, thereby improving the stability of the connection between the retaining plate 12 and the rectangular anti-slide pile 11; when the steel reinforcement strip 14 is connected to the embedded steel reinforcement 8, for example, refer to Figure 14 Four reinforcing bars 14 are evenly arranged around the pre-embedded reinforcing bars 8, with an angle of 90° between adjacent reinforcing bars 14. The gap between the reinforcing bars 14 and the pre-embedded reinforcing bars 8 is welded to form a weld 15. Setting multiple reinforcing bars 14 can further improve the stability of the connection between the retaining plate 12 and the rectangular anti-slide pile. The diameter of the pre-embedded reinforcing bars 8 meets the requirements for supporting the retaining plate 12, thus preventing the pre-embedded reinforcing bars 8 from bending during the installation of the retaining plate 12.

[0057] After the retaining plate 12 is connected to the rectangular anti-slide pile 11, C35 fine aggregate concrete is used to seal the anchor in the installation groove 121 of the retaining plate 12; see the schematic diagram of the installation of a single retaining plate 12 and rectangular anti-slide pile 11 for reference. Figure 12 .

[0058] During the installation of retaining plates 12 between two adjacent rectangular anti-slide piles 11, multiple retaining plates 12 are installed sequentially from top to bottom to the first depth.

[0059] S203. Determine whether the cumulative first excavation depth of the soil between the piles has reached the design depth. If yes, end the excavation of the soil between the piles and the installation of the retaining plate 12. If not, repeat S201 and S202 until the cumulative excavation depth of the soil between the piles reaches the design depth and the cumulative installation depth of the retaining plate 12 reaches the design depth.

[0060] For example, when the cumulative installation depth of the retaining plate 12 is 10m, the height of a single retaining plate 12 is 50cm, and the first depth of a single excavation is 2m, during the installation of the retaining plate 12, in S201, the first depth is 2m; in S202, four retaining plates 12 are installed from top to bottom. After repeating S201 and S202 five times, the cumulative installation depth of the retaining plate 12 reaches the design depth.

[0061] During the construction of retaining wall 12, when the design depth is relatively deep (e.g., greater than 6m), two types of retaining wall 12 with different thicknesses are used. The first type of retaining wall 12 is located within a depth range of 0 to 6m below the top of the rectangular anti-slide pile 11, and the second type of retaining wall 12 is located within a depth range of 6m below the top of the rectangular anti-slide pile 11 to the design depth. The thickness of the second type of retaining wall is greater than that of the first type of retaining wall. By using two types of retaining wall with different thicknesses, the thicker retaining wall is located in a deeper area below the top of the rectangular anti-slide pile, which can further improve the bearing capacity against lateral earth pressure on the slope, improve the protection effect of the slope soil, and prevent slope landslides.

[0062] The specific dimensions of the retaining plate 12 (such as length, height, thickness, etc.) are determined according to the design and construction requirements. For example, the length of the retaining plate 12 is 420cm, the height is 50cm, and the thickness is 34cm and 40cm respectively, with a design depth of 10m. When installing the retaining plate 12, the retaining plate 12 with a thickness of 34cm is installed within a depth of 6m below the top of the rectangular anti-slide pile 11. When the installation depth of the retaining plate 12 with a thickness of 34cm reaches 6m, a retaining plate 12 with a thickness of 40cm is installed below the bottom retaining plate 12 with a thickness of 34cm to a depth of 10m.

[0063] During the construction of retaining plate 12, for a row of rectangular anti-slide piles, retaining plates can be installed starting from the end of the row of rectangular anti-slide piles, along the height direction and the length direction of the row of rectangular anti-slide piles, so that the retaining plates and the rectangular anti-slide piles are connected into an integral structure. The installation of retaining plates in the height direction and length direction of the row of rectangular anti-slide piles can be carried out simultaneously, or the installation of retaining plates in the height direction of the row of rectangular anti-slide piles can be carried out first, followed by the installation of retaining plates in the length direction of the row of rectangular anti-slide piles; a schematic diagram of the connection between rectangular anti-slide piles and multiple retaining plates is shown below. Figure 10 , Figure 11 As shown.

[0064] The above description is merely a detailed illustration of specific embodiments of the present invention and is not intended to limit the invention. Various substitutions, modifications, and improvements made by those skilled in the art without departing from the principles and scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method for mechanically drilling rectangular anti-slide piles, characterized in that, include: S101. Construction preparation: Level the site, remove loose soil from the slope, excavate and compact the loose soil layer in the site. S102. Measurement and layout; Re-measure the construction control elevation, water diversion benchmark, measure the ground elevation of the pile hole, level the site to the pile top elevation, and calculate the excavation depth; mark the pile perimeter boundary using white lime lines based on the pile position cross lines. S103, Lock construction; construct the lock within the marked pile perimeter boundary, with the central section of the lock having a rectangular cross-section; S104, Mechanical drilling; Mark the excavation area inside the opening of the lock, mark area one and area two in the middle area of ​​the opening, mark area three on the left and right sides of the first side of the opening respectively, mark area four between area one, area two and the third side of the opening, and mark area four between area one, area two and the fourth side of the opening. Install a circular drill bit on a rotary drilling rig and construct circular holes in Area 1 and Area 2 respectively until the bottom of the designed hole is reached. Replace the round drill bit with a rectangular drill bit that matches the dimensions of area three, and drill a hole in area three to the designed depth. The pile body was milled using a rectangular drill bit with dimensions consistent with the rectangular anti-slide pile, and the hole was repaired in area four to the bottom of the designed hole. S105, Reinforcing cage construction: The reinforcing cage of the rectangular anti-slide pile is divided into multiple sections. The reinforcing cages of adjacent sections are connected in sequence and lowered into the pile hole. According to the design installation depth requirements of the retaining plate, the pre-embedded reinforcing bars and end-cap templates are installed on the corresponding sections of the reinforcing cage. The end-cap templates close the sides of the rectangular hole in area three. The pre-embedded reinforcing bars extend out of the end-cap templates and are located in the rectangular hole in area three. After the reinforcing cage is installed, fine-grained soil is backfilled into the rectangular hole formed by excavation in area three. S106. Conduit installation: The conduit is hoisted using hoisting equipment. During the lowering of the conduit into the reinforcing cage, the conduit is positioned at the center of the borehole. The conduit is hoisted and extended section by section and lowered vertically. S107, Concrete pouring; After constructing a row of rectangular anti-slide piles, the retaining wall is then constructed.

2. The construction method for mechanical drilling of rectangular anti-slide piles according to claim 1, characterized in that, In step S105, when the reinforcing cage is divided into two sections, the first section of the reinforcing cage is located at the bottom of the hole, and the second section of the reinforcing cage is connected to the first section and located on top of the first section. When making the second section of the reinforcing cage, two sets of pre-embedded reinforcing bars are fixed on one side of the reinforcing cage near the opening. The two sets of pre-embedded reinforcing bars are respectively set close to the left and right sides of the reinforcing cage. Each set of pre-embedded reinforcing bars includes multiple pre-embedded reinforcing bars, which are evenly arranged along the height direction of the reinforcing cage. Then, a head template is installed on one side of the reinforcing cage near the opening. The head template is installed on the outside of the reinforcing cage, and multiple head templates are arranged along the height direction of the reinforcing cage.

3. The construction method for mechanical drilling of rectangular anti-slide piles according to claim 2, characterized in that, When installing the end cap template, holes are made in the end cap template at the positions of the pre-embedded reinforcing bars corresponding to the reinforcing cage, so that the pre-embedded reinforcing bars pass through the end cap template and are connected to the end cap template. The end cap template and the reinforcing cage are supported by protective layer spacers.

4. The construction method for mechanical drilling of rectangular anti-slide piles according to claim 3, characterized in that, After the end cap template is installed, galvanized iron wire mesh is connected to the left and right sides of the end cap template respectively. Along the height direction of the end cap template, galvanized iron wire mesh and end cap template are connected at certain intervals using rivets.

5. The construction method for mechanical drilling of rectangular anti-slide piles according to claim 4, characterized in that, When installing the second section of the reinforcing cage, hoist it above the first section of the reinforcing cage at the borehole opening. Adjust the position of the second section of the reinforcing cage so that the end cap template is aligned with the first side of the lock opening, and align the lower part of the second section of the reinforcing cage with the top of the first section of the reinforcing cage. After connecting the first and second sections of the reinforcing cage with threaded sleeves, lower the first and second sections of the reinforcing cage together, so that the first section of the reinforcing cage is lowered to the bottom of the borehole. The end cap template on the second section of the reinforcing cage closes the side of the rectangular hole in area three. The pre-embedded reinforcing bars on the second section of the reinforcing cage extend out of the end cap template and are located in the rectangular hole in area three. The galvanized wire mesh on both sides of the end cap template seals the gap between the end cap template and the pile hole wall.

6. The construction method for mechanically drilling rectangular anti-slide piles according to claim 1, characterized in that, The construction of the retaining wall includes the following steps: S201. Mechanically excavate the soil between the piles on the outer side of the rectangular anti-slide piles, with the excavation depth being the first depth. S202. Install multiple retaining plates from top to bottom between two adjacent rectangular anti-slide piles to the first depth; S203. Determine whether the cumulative first excavation depth of the soil between piles has reached the design depth. If yes, end the excavation of the soil between piles and the installation of the retaining plate. If not, repeat S201 and S202 until the cumulative excavation depth of the soil between piles reaches the design depth and the cumulative installation depth of the retaining plate reaches the design depth.

7. The construction method for mechanically drilling rectangular anti-slide piles according to claim 6, characterized in that, In step S201, when the excavation reaches the location of the rectangular anti-slide pile, the soil between area three is removed to expose the end cap template, and then the end cap template is removed from the rectangular anti-slide pile.

8. The construction method for mechanical drilling of rectangular anti-slide piles according to claim 6, characterized in that, The retaining plate has a rectangular cross-section and is provided with mounting through holes. The mounting through holes are respectively located near the left and right surfaces of the retaining plate and penetrate the retaining plate through the thickness direction. The retaining plate is also provided with a recessed mounting groove, which is coaxial with the mounting through holes. The mounting groove is recessed on the front side of the retaining plate and is provided with a steel pad at the bottom of the mounting groove.

9. The construction method for mechanically drilling rectangular anti-slide piles according to claim 7, characterized in that, The installation process for a single retaining plate includes: Position the retaining plate between two adjacent rectangular anti-slide piles, and align the installation through hole of the retaining plate with the pre-embedded steel bars on the rectangular anti-slide piles; Push the retaining plate so that the pre-embedded steel bars pass through the installation through holes and steel pads on the retaining plate, and after the rear side of the retaining plate contacts the surface of the rectangular anti-slide pile, use steel bar welding to limit and fix it. C35 fine aggregate concrete was used to seal the anchors in the installation slots of the retaining plate.

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