Conical concrete prefabricated retaining wall manual hole digging uplift pile construction method
By using conical concrete prefabricated wall guards in the construction of artificial hole-drilling pile foundations, the safety hazards and complex construction problems in the existing technology are solved, the continuity and safety of construction are achieved, the pull-resistant bearing capacity is improved, and the green construction requirements are met.
Patent Information
- Application Number
- CN202411720724.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-04-08
AI Technical Summary
In the construction of existing artificial hole-drilling pile foundations, the concrete wall guard has safety hazards, the construction process is complex and time-consuming, and it is difficult to fully utilize the lateral friction resistance between the wall guard and the soil, and it is difficult to meet the bearing capacity design requirements.
The prefabricated wall guard of conical concrete is used to form prefabricated wall guards by prefabricated in the factory and assembled on site, which simplifies the construction process and improves construction safety. Through the design of the prefabricated wall guards, the friction resistance between the wall guards and the soil is enhanced.
It achieves the continuity and safety of construction, shortens the construction period, improves the resistance to pull-up bearing capacity, reduces the construction difficulty and project cost, and is in line with the environmental protection green construction method.
Smart Images
Figure CN119777360A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of bored pile construction, and in particular relates to a construction method of a conical concrete prefabricated retaining wall artificially bored anti-pulling pile. Background Art
[0002] The construction risk is relatively high during the manual excavation process, and risks such as hole wall collapse and soil sliding are prone to occur. During the construction process, a retaining wall needs to be set up to ensure the safety of the workers. At present, the foundation of manually excavated bored piles generally adopts the method of cast-in-place reinforced concrete retaining wall. This method has the following shortcomings: during the construction process, formwork, steel bar tying, concrete pouring and other processes are required. The construction process is relatively complicated and the construction time is long. The quality of retaining wall concrete maintenance is not easy to guarantee, the concrete retaining wall effect may be insufficient, and there are safety hazards. It is difficult to give full play to the lateral friction resistance between the retaining wall and the soil around the pile, and it is difficult to meet the bearing capacity design requirements. Summary of the invention
[0003] The technical problem to be solved by the invention is: to provide a construction method of artificially dug anti-pulling piles for conical concrete prefabricated retaining walls in view of the potential safety hazards of concrete retaining walls.
[0004] The technical solution of the present invention is specifically as follows: A method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pullout pile comprises the following steps: S1. Locate pile holes at the construction site; S2. Install lifting equipment, which is used for lowering and installing prefabricated segments and steel bars; S3, excavating the soil in steps to form a pile hole; hoisting a prefabricated pipe segment with an opening and a tongue-and-groove at the bottom to the excavation surface of the pile hole, and installing multiple conical prefabricated pipe segments on the inner wall of the pile hole by circumferential and longitudinal splicing to form a prefabricated retaining wall; the shape of the prefabricated pipe segment is a conical structure with a small top and a large bottom, and a tongue-and-groove at the bottom; the prefabricated retaining wall is a conical retaining wall with a tongue-and-groove at the bottom; S4, repeat step S3, assemble the prefabricated retaining wall while excavating the soil, and ensure that each ring of the prefabricated retaining wall is stably fixed until the soil is excavated and the prefabricated retaining wall is installed to the designed elevation of the pile bottom; S5, using lifting equipment to hoist the steel bars into the pile hole and manually tying the pile reinforcement cage; S6. Pour concrete into the pile body.
[0005] In step S2, each time a soil section is excavated, a ring of prefabricated retaining wall is fixed to the soil; when the n+1th soil section is excavated, firstly, a single segment pile hole is excavated to both sides along the connection seam of the nth prefabricated retaining wall, a single prefabricated segment is sunk into the single segment pile hole, and the next single segment pile hole is excavated to one side of the single segment pile hole, and a single prefabricated segment is continuously sunk, and the above steps are repeated until the single segment pile holes are connected end to end to form a complete pile hole, and the prefabricated segments are assembled into a ring in the pile hole; n=1,2,3,4..., increasing in sequence.
[0006] In step S2, the specific steps of excavating the soil in steps are: excavating the nth section of soil, excavating layer by layer from top to bottom, first excavating the middle part, and then expanding to the periphery to form a pile hole; during the excavation process, the excavation cross-sectional size is always controlled, n=1,2,3,4..., increasing in sequence.
[0007] In step S2, the specific assembly steps of the prefabricated retaining wall are as follows: assemble the nth section of the prefabricated retaining wall, after the excavation of the nth section of the soil is completed, the prefabricated pipe segments are suspended and sunk into the corresponding positions in the pile hole one by one through wire ropes, and each prefabricated pipe segment is connected in the pile hole using radial bent bolts to assemble into a complete ring of conical retaining wall, and at the same time, the upper and lower adjacent rings of retaining walls are connected into a whole through longitudinal connecting bolts to form a prefabricated retaining wall; n=1,2,3,4..., increasing in sequence.
[0008] In step S2, bolt holes are reserved in the circumferential and longitudinal directions of the prefabricated pipe segments. The prefabricated pipe segments are designed according to the actual engineering conditions to determine the wall thickness, prefabricated pipe segment height, number of segments and prefabricated pipe segment hole size; the prefabricated pipe segments are assembled into a closed-loop conical wall using bent bolts, and the upper and lower adjacent conical wall guards are longitudinally connected and fixed using tongue-and-groove and longitudinal connecting bolts, ultimately forming a conical hollow space wall guard structure.
[0009] In step S4, the main reinforcement, stirrups and reinforcing bars of the pile foundation are respectively suspended into the hole and manually tied directly in the hole to form a steel cage.
[0010] In step S5, when pouring concrete, continuous pouring is performed using a conduit, which is connected by a socket and spigot connection and sealed by a rubber ring or a rubber plate. The length of each conduit section is 2m, and the depth of the conduit buried in the concrete is maintained to be no less than 1m. After the concrete pouring is completed, the conduit is slowly pulled out, and the conduit is repeatedly inserted before being lifted from the concrete surface to avoid hollow piles.
[0011] The opening rate of the prefabricated pipe segment is less than or equal to 40%, and the opening direction is inclined upward, and the angle between the opening direction and the horizontal plane is 10°; the height of the single-section excavated soil is 300-500mm.
[0012] The lower diameter of the prefabricated protective wall is 50-60mm larger than the upper diameter, ensuring that the upper part is smaller and the lower part is larger; the thickness of the prefabricated pipe segment is 50-60mm, the weight is 40-60kg, and the height is 300-500mm.
[0013] According to the actual situation on site, each ring of prefabricated retaining wall includes 3-6 prefabricated pipe segments; the steel bars are hoisted to the pile holes by lifting equipment and manually tied into steel cages in the pile holes; the lifting equipment is SISINSING small gantry electric crane with a maximum lifting weight of 500kg.
[0014] The beneficial effects of the present invention are: having the following advantages: 1. The conical concrete prefabricated retaining wall structure of the present invention is prefabricated in the factory and assembled on site, and does not require the formwork and pouring of the cast-in-place retaining wall, thereby ensuring the continuity of construction and effectively shortening the construction period. The present invention adopts a prefabricated retaining wall, the quality of which is easy to control, the structural strength is guaranteed, and the construction safety of the operators can be guaranteed. The prefabricated retaining wall does not require on-site production of components or on-site mixing of concrete, thereby reducing the impact on the surrounding environment, and is an environmentally friendly green construction method.
[0015] 2. This method uses a prefabricated retaining wall with holes. By opening holes in the prefabricated segments, the weight of the prefabricated segments is reduced, which is convenient for manual lifting and construction. It is especially suitable for manual hole-digging foundation construction and mountainous and hilly areas where large equipment cannot be used for transportation.
[0016] 3. The prefabricated pipe segment of the present invention adopts a hole-opening method, and the angle between the hole-opening direction and the horizontal direction is about 10°, which makes it convenient for concrete to flow into the holes and into the space between the retaining wall and the soil during the concrete pouring process, effectively filling the retaining wall and the surrounding soil, and can effectively ensure the lateral resistance of the foundation piles, thereby improving the pull-out bearing capacity.
[0017] 4. The retaining wall structure of the present invention uses reserved bolt holes with tongues and grooves at the bottom, which makes it convenient for workers to carry out circumferential and longitudinal connection and assembly of multiple prefabricated pipe segments in the narrow space in the hole; at the same time, when excavating downward, the tongue and groove at the bottom of the prefabricated retaining wall is embedded in the surrounding soil to increase the longitudinal stability of the retaining wall during the support construction process.
[0018] 5. The conical prefabricated retaining wall bored pile structure of the present invention, which is small at the top and large at the bottom, can effectively improve the restraint of the foundation soil on the pile body during pull-out resistance. The setting of the inclined side wall increases the normal stress of the foundation soil on the pile body. According to the theory of tribology, it is concluded that the friction coefficient remains unchanged and the increase of the normal stress can increase the friction force on the pile side. The increase of the friction force on the pile side enhances the pile-soil interaction. At the same time, the normal stress can be decomposed in the horizontal and vertical directions to obtain the effect of the foundation soil on the wedge pile. The pull-out bearing capacity of the pile type is finally increased. Therefore, the pile body bearing capacity can meet the design requirements within a smaller depth range, and the design optimization of shortening the pile length can be realized, so as to achieve the purpose of saving engineering costs and reducing construction difficulty.
[0019] 6. The conical prefabricated concrete retaining wall of the present invention can be prefabricated and directly hoisted into the hole and assembled when digging a hole at the construction site, so it has the characteristics of short construction period and high safety. At the same time, the conical prefabricated concrete retaining wall of the present invention adopts a small upper and large lower structure, which can give full play to the friction resistance between the retaining wall and the soil during pull-out resistance, and significantly improve the bearing capacity of the pull-out pile.
[0020] 7. The prefabricated pipe segments adopted in the construction method of the present invention are prefabricated in the factory and assembled on the construction site, which can improve the construction efficiency, avoid the requirements of the traditional cast-in-place retaining wall concrete on the age strength, significantly shorten the construction period of the pile foundation, and ensure the reliability and safety of the pile foundation construction; at the same time, the setting of the prefabricated conical retaining wall with a small top and a large bottom can significantly increase the normal force of the soil around the pile on it when the pile foundation is pulled out, thereby increasing the friction force on the pile side when the pile foundation is pulled out, improving the pull-out bearing capacity of the pile body, and then optimizing the pile length and saving the project cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic diagram of the construction process of the present invention; Figure 2 It is a schematic diagram of the structure of the prefabricated retaining wall; Figure 3 It is a structural schematic diagram of the prefabricated segment; Figure 4 It is a schematic diagram of the longitudinal connection of the prefabricated retaining wall; Figure 5 It is a schematic diagram of the circumferential connection of the prefabricated retaining wall; Figure 6 It is a schematic diagram of the construction method of the present invention; Figure 7 It is a schematic diagram of the calculation model of precast concrete assembled wall protection structure under uniformly distributed confining pressure. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0024] like Figure 1 , Figure 6 As shown, a method for constructing a conical concrete prefabricated retaining wall manually dug anti-pullout pile comprises the following steps: S1. Locate pile holes at the construction site; S2, installing a lifting device 5, the lifting device 5 is used for lowering and installing the prefabricated segments 1 and the steel bars; S3, excavating the soil 7 in steps to form a pile hole; hoisting a prefabricated pipe segment 1 with an opening and a tongue-and-groove at the bottom to the excavation surface of the pile hole, and installing multiple conical prefabricated pipe segments 1 on the inner wall of the pile hole by circumferential and longitudinal splicing to form a prefabricated retaining wall 8; the shape of the prefabricated pipe segment 1 is a conical structure with a small top and a large bottom, and a tongue-and-groove at the bottom; the prefabricated retaining wall 8 is a conical retaining wall with a tongue-and-groove at the bottom; S4, repeat step S3, assemble the prefabricated retaining wall 8 while excavating the soil, and ensure that each ring of the prefabricated retaining wall is stably fixed until the soil is excavated and the prefabricated retaining wall is installed to the designed elevation of the pile bottom; S5, using the lifting device 5 to hang the steel bars into the pile hole, and manually tying the pile reinforcement cage 9; S6. Pouring pile body concrete 10.
[0025] Preferably, in step S2, each time a soil section is excavated, a ring of prefabricated retaining wall is fixed to the soil; when the n+1th soil section is excavated, a single segment pile hole is first excavated to both sides along the connection seam of the nth prefabricated retaining wall, a single prefabricated segment is sunk into the single segment pile hole, and the next single segment pile hole is excavated to one side of the single segment pile hole, and a single prefabricated segment is continuously sunk, and the above steps are repeated until the single segment pile holes are connected end to end to form a complete pile hole, and the prefabricated segments are assembled into a ring in the pile hole; n=1,2,3,4..., increasing in sequence.
[0026] Preferably, in step S2, the specific steps of excavating the soil in steps are: excavating the nth section of soil, excavating layer by layer from top to bottom, first excavating the middle part, and then expanding to the periphery to form a pile hole; during the excavation process, the excavation cross-sectional size is always controlled, n=1,2,3,4..., increasing in sequence.
[0027] Preferably, in step S2, the specific assembly steps of the prefabricated retaining wall 8 are: assemble the nth section of the prefabricated retaining wall, after the excavation of the nth section of the soil is completed, suspend the prefabricated pipe segments one by one through the steel wire rope 6 and sink them into the corresponding position in the pile hole, use radial bent bolts 3 to connect each prefabricated pipe segment in the pile hole to assemble into a complete ring of conical retaining wall, and at the same time use longitudinal connecting bolts 4 to connect the upper and lower adjacent full ring retaining walls into a whole to form a prefabricated retaining wall; n=1,2,3,4..., increasing in sequence.
[0028] Preferably, in step S2, bolt holes are reserved in the circumferential and longitudinal directions of the prefabricated segments, and the prefabricated segments are designed according to actual engineering conditions to determine the thickness of the protective wall, the height of the prefabricated segments, the number of segments and the size of the holes in the prefabricated segments; the prefabricated segments are assembled into a closed-loop conical protective wall using 6.8-grade 3M16 bent bolts 3, and the upper and lower adjacent conical protective walls are longitudinally connected and fixed using tongue-and-groove plus 6.8-grade 4M16 longitudinal connecting bolts 4, ultimately forming a conical hollow space protective wall structure.
[0029] Preferably, in step S2, the assembly method of the prefabricated retaining wall 8 is as follows: the individual prefabricated pipe segments 1 with openings in the whole ring and tongues and grooves at the bottom are suspended and sunk into the pile hole by steel wire ropes 6, and assembled into a ring in the pile hole; the prefabricated pipe segments are assembled into a closed-loop retaining wall using 6.8-grade 3M16 bent bolts 3, and the upper and lower adjacent retaining walls are longitudinally connected and fixed using tongues and grooves plus 6.8-grade 4M16 longitudinal connecting bolts 4, to finally form a conical hollow space retaining wall structure.
[0030] Preferably, in step S4, most of the traffic conditions in mountainous and hilly areas are poor, construction machinery cannot reach, the length and diameter of the steel cage are large and the steel processing site is relatively small. It is difficult to first tie the steel cage 9 and then hoist it. Therefore, the main reinforcement, stirrups and reinforcing bars of the pile foundation are respectively hoisted into the hole and manually tied directly in the hole to form the steel cage 9.
[0031] Preferably, in step S5, when pouring concrete 10, continuous pouring is performed using a conduit, the conduit adopts a socket connection, and is sealed with a rubber ring or a rubber plate. The length of each conduit section is 2m, and the depth of the conduit buried in the concrete is maintained to be no less than 1m; after the concrete pouring is completed, the conduit is slowly pulled out, and the conduit is repeatedly inserted before being lifted from the concrete surface to avoid hollow piles.
[0032] Preferably, the opening rate of the prefabricated pipe segment is less than or equal to 40%, and the opening direction is inclined upward, and the angle between the opening direction and the horizontal plane is 10°; the height of a single-section excavated soil body is determined according to the height of the prefabricated pipe segment. Considering the weight of the prefabricated pipe segment and the convenience of construction, the excavation height is generally 300-500mm.
[0033] Preferably, the lower diameter of the prefabricated protective wall 8 is 50-60 mm larger than the upper diameter, ensuring that the upper part is smaller and the lower part is larger; the thickness of the prefabricated pipe segment 1 is 50-60 mm, the weight is 40-60 kg, and the height is 300-500 mm.
[0034] Preferably, according to the actual situation on site, each ring of prefabricated retaining wall includes 3-6 prefabricated pipe segments 1; the steel bars are hoisted to the pile holes by lifting equipment and manually tied into steel cages 9 in the pile holes; the single prefabricated pipe segments connected in the annular direction use 6.8-level 3M16 bent bolts; the single prefabricated pipe segments connected longitudinally use 6.8-level 4M16 hexagonal bolts, i.e. longitudinal connecting bolts 4; the lifting equipment is a SISINSING small gantry electric crane with a maximum lifting weight of 500kg.
[0035] Example 1 A method for constructing a conical concrete prefabricated retaining wall with artificially dug holes for pulling-out piles, the process is as follows: Figure 1 As shown, the following steps are included: S1. Pile hole positioning: Pile measurement and positioning work is carried out before construction. First, the main control axis is measured and laid out according to the coordinate relationship between the construction control point and the main control axis. Then the main control axis is encrypted step by step, and each axis is measured and laid out. Finally, according to the coordinate position relationship between the pile center and the axis, the pile center control cross line is measured and laid out. After the pile position is laid out, it is repeatedly checked and the excavation stage is entered.
[0036] S2. Installing lifting equipment 5: Installing lifting equipment 5 at the construction site to facilitate the lowering and installation of the prefabricated segments 1 and steel bars.
[0037] S3, excavation of soil 7; Figure 6 As shown, the excavation of the soil body 7 should be carried out section by section from top to bottom, first digging the middle part and then expanding to the periphery. Attention should be paid to controlling the cross-sectional size of the excavation at all times during the excavation process. In this embodiment, the upper pile diameter D=2.0m, the lower pile diameter D=2.05m, the excavation depth h=7m, the single excavation height is 0.5m, and the single-ring prefabricated retaining wall 8 is assembled from 6 prefabricated pipe segments 1. The single-piece gross weight of the prefabricated pipe segment 1 is 69.27kg, the number of holes in a single piece is 6, the hole width is 300mm, the hole height is 150mm, and the opening rate is 49.7%.
[0038] The prefabricated segment 1 is subjected to the force of the soil 7 during construction. The design of the prefabricated segment 1 can be based on the normal force qand tangential force N It can be calculated as follows: ; ; in, is the lateral static earth pressure, is the weight of the soil 7 above the prefabricated segment 1, It is the angle between the prefabricated segment 1 and the longitudinal direction.
[0039] S4, assembling prefabricated retaining wall 8; after the excavation of the nth section of soil 7 is completed, assembling the nth section of prefabricated retaining wall 8, the prefabricated pipe segment 1 of the prefabricated retaining wall 8 is suspended by a wire rope 6 and sunk into the corresponding position in the pile hole, the prefabricated pipe segment 1 is as Figure 3 As shown, a complete ring of prefabricated retaining wall 8 is assembled in the pile hole using 6.8-grade 3M16 bent bolts 3, as shown in FIG. Figure 2 As shown, the 6.8-grade 4M16 longitudinal connecting bolts 4 and the steel pads 2 are used to fix the tongue and groove and the upper joint of the upper and lower prefabricated segments 1, as shown in FIG. Figure 4 , 5 As shown, the assembled prefabricated retaining wall 8 is stably fixed on the soil 7 around the pile; n=1, 2, 3, 4, ..., 14, increasing in sequence. Steps S3 and S4 are repeated until the soil 7 is excavated and the prefabricated retaining wall 8 is installed to the designed elevation of the pile bottom.
[0040] S5, tying the steel cage 9; using the lifting device 5 to hoist the steel bars into the pile holes for tying.
[0041] S6. Pouring concrete 10. The pile core concrete is continuously poured using a conduit, which is connected by a socket and spigot connection and sealed with a rubber ring or a rubber plate. The length of each conduit section is about 2m, and the length of the lowest section is 3m.
[0042] The conduit needs to be lifted during pouring. During the lifting process, the depth of the conduit buried in the concrete 10 is kept not less than 1m. The concrete 10 flows into the hole and enters the gap between the prefabricated retaining wall 8 and the soil 7, connecting the prefabricated retaining wall 8 with the surrounding soil 7; after the concrete 10 is poured, the conduit is slowly pulled out, and the conduit must be repeatedly inserted before it is lifted from the concrete surface to avoid hollow piles; the concrete 10 freely flows into the hole of the prefabricated pipe segment 1 and between the prefabricated retaining wall 8 and the soil 7, effectively bonding the prefabricated retaining wall 8 with the surrounding soil 7.
[0043] The static load test results of the prefabricated retaining wall artificial hole excavation anti-pullout piles in this embodiment and the traditional cast-in-place retaining wall artificial hole excavation anti-pullout piles are compared as shown in the figure. Figure 7 shown.
[0044] Example 2 A method for constructing a conical concrete prefabricated retaining wall with artificially dug holes for pulling-out piles, the process is as follows: Figure 1As shown, the following steps are included: S1. Locate the pile holes at the construction site; perform pile measurement and positioning work before construction. First, measure and lay out the main control axis according to the coordinate relationship between the construction control point and the main control axis. Then, encrypt the main control axis step by step, measure and lay out each axis, and finally, measure and lay out the pile center control cross line according to the coordinate position relationship between the pile center and the axis. After the pile position is laid out, it is repeatedly checked and enters the excavation stage. The lifting equipment 5 is a SISINSING small gantry electric crane with a maximum lifting weight of 500kg.
[0045] S2. Install the lifting device 5, which is used for lowering and installing the prefabricated segments 1 and steel bars.
[0046] S3, excavating the soil 7 in steps to form a pile hole; hoisting a conical prefabricated pipe segment 1 with an opening and a tongue and groove at the bottom to the excavation surface of the pile hole, and installing it on the inner wall of the pile hole by circumferential and longitudinal splicing to form a prefabricated retaining wall 8; like Figure 6 As shown in FIG. 1 , the excavation of the soil body 7 should be carried out step by step from top to bottom. When excavating the first section of the soil body 7, the middle part is excavated first, and then the periphery is expanded. It is noted that the cross-sectional size of the excavation is always controlled during the excavation process to form a pile hole. After the excavation of the first section of the soil body 7 is completed, the first section of the prefabricated retaining wall 8 is assembled, and the prefabricated pipe segment 1 of the prefabricated retaining wall 8 is suspended and sunk into the corresponding position in the pile hole by the steel wire rope 6. The prefabricated pipe segment 1 is as shown in FIG. Figure 3 As shown, a complete ring of prefabricated retaining wall 8 is assembled in the pile hole using 6.8-grade 3M16 bent bolts 3, as shown in FIG. Figure 2 As shown, the 6.8-grade 4M16 hexagonal bolts 4 and the steel pads 2 are used to fix the tongue and groove and the upper joint of the upper and lower prefabricated segments 1, as shown in FIG. Figure 4 , 5 As shown, the assembled prefabricated retaining wall 8 is stably fixed on the soil 7 around the pile.
[0047] When excavating the second section of soil 7, first excavate a single segment pile hole corresponding to a single prefabricated segment 1 downward along the connection seam of the first section of prefabricated retaining wall 8. After the single segment pile hole is excavated, due to the presence of soil 7 on both sides of the single segment pile hole, the prefabricated segment 1 of the upper prefabricated retaining wall 8 can be effectively supported, and the upper prefabricated retaining wall 8 can be prevented from collapsing. The single prefabricated segment 1 is sunk into the single segment pile hole, so that the prefabricated segment 1 and the prefabricated segment of the upper prefabricated retaining wall 8 are aligned. 1, and then dig out the next single-segment pile hole to one side of the single-segment pile hole, continue to sink a single prefabricated segment 1, repeat the above steps until the single-segment pile holes are connected end to end to form a complete pile hole, and assemble the prefabricated segments 1 into a ring in the pile hole; use 6.8-level 3M16 bent bolts 3 to assemble the prefabricated segments 1 into a closed-loop conical retaining wall, and use tongue-and-groove plus 6.8-level 4M16 hexagonal head bolts 4 to longitudinally connect and fix the upper and lower adjacent conical retaining walls, such as Figure 4 ,5 As shown, the assembled prefabricated retaining wall 8 is stably fixed on the soil 7 around the pile, and finally a conical hollow space retaining wall structure is formed.
[0048] In this embodiment, the upper pile diameter D=2.0m, the lower pile diameter D=2.05m, the excavation depth h=7m, the single excavation height is 0.3m, and the single-ring prefabricated retaining wall 8 is assembled from 6 prefabricated pipe segments 1. The single-piece gross weight of the prefabricated pipe segment 1 is 41.56kg, the number of holes in a single piece is 6, the hole width is 180mm, the hole height is 90mm, and the opening rate is 49.7%.
[0049] The prefabricated segment 1 is subjected to the force of the soil 7 during construction. The design of the prefabricated segment 1 can be based on the normal force q and tangential force N It can be calculated as follows: ; ; in, is the lateral static earth pressure, is the weight of the soil 7 above the prefabricated segment 1, It is the angle between the prefabricated segment 1 and the longitudinal direction.
[0050] S4, repeat the steps of excavating the second section of soil 7 and assembling the prefabricated retaining wall 8, assembling the prefabricated retaining wall 8 while excavating the soil 7, and ensuring that each ring of the prefabricated retaining wall 8 is stably fixed, until the soil 7 is excavated and the prefabricated retaining wall 8 is installed to the designed elevation of the pile bottom, such as Figure 2 shown.
[0051] S5, using the lifting device 5 to hang the steel bars into the pile hole, and manually tying the pile reinforcement cage 9; Most of the traffic conditions in mountainous and hilly areas are poor and construction machinery cannot reach them. The steel cage 9 is large in length and diameter and the steel processing site is relatively small. It is difficult to tie the steel cage 9 first and then hoist it. Therefore, the main reinforcement, stirrups and reinforcing bars of the pile foundation are separately hoisted into the hole and manually tied directly in the hole to form the steel cage 9.
[0052] S6. Pouring pile body concrete 10.
[0053] When pouring concrete 10, a conduit is used for continuous pouring. The conduit adopts a socket connection and is sealed with a rubber ring or a rubber plate. The length of each section of the conduit is about 2m, and the length of the lowest section is 3m. The depth of the conduit buried in the concrete 10 is kept not less than 1m. After the pouring of the concrete 10 is completed, the conduit is slowly pulled out, and the conduit is repeatedly inserted before being lifted from the concrete surface to avoid the formation of hollow piles.
[0054] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, which should also be regarded as the scope of protection of the present invention.
Claims
1. A method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile, characterized in that: The following steps are involved: S1. Locate pile holes at the construction site; S2, installing a lifting device (5), the lifting device (5) being used for lowering and installing the prefabricated segments (1) and the steel bars; S3, excavating the soil (7) in steps to form a pile hole; hoisting a prefabricated pipe segment (1) with an opening and a tongue-and-groove at the bottom to the excavation surface of the pile hole, and installing a plurality of conical prefabricated pipe segments (1) on the inner wall of the pile hole by circumferential and longitudinal splicing to form a prefabricated retaining wall (8); the shape of the prefabricated pipe segment (1) is a conical structure with a small top and a large bottom, and a tongue-and-groove at the bottom; the prefabricated retaining wall (8) is a conical retaining wall with a tongue-and-groove at the bottom; S4, repeating step S3, assembling the prefabricated retaining wall (8) while excavating the soil, and ensuring that each ring of the prefabricated retaining wall is stably fixed, until the soil is excavated and the prefabricated retaining wall is installed to the designed elevation of the pile bottom; S5, using a lifting device (5) to hoist the steel bars into the pile hole, and manually tying the pile reinforcement cage (9); S6. Pouring pile body concrete (10).
2. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: In step S2, each time a soil section is excavated, a ring of prefabricated retaining wall is fixed to the soil; when the n+1th soil section is excavated, firstly, a single segment pile hole is excavated to both sides along the connection seam of the nth prefabricated retaining wall, a single prefabricated segment is sunk into the single segment pile hole, and the next single segment pile hole is excavated to one side of the single segment pile hole, and a single prefabricated segment is continuously sunk, and the above steps are repeated until the single segment pile holes are connected end to end to form a complete pile hole, and the prefabricated segments are assembled into a ring in the pile hole; n=1,2,3,4..., increasing in sequence.
3. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: In step S2, the specific steps of excavating the soil in steps are: excavating the nth section of soil, excavating layer by layer from top to bottom, first excavating the middle part, and then expanding to the periphery to form a pile hole; during the excavation process, the excavation cross-sectional size is always controlled, n=1,2,3,4..., increasing in sequence.
4. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: In step S2, the specific assembly steps of the prefabricated retaining wall (8) are as follows: assembling the nth section of the prefabricated retaining wall, after the excavation of the nth section of the soil is completed, the prefabricated pipe segments are suspended and sunk into the corresponding positions in the pile hole one by one through the steel wire rope (6), and each prefabricated pipe segment is connected in the pile hole using radial bent bolts (3) to assemble into a complete ring of conical retaining wall, and at the same time, the upper and lower adjacent complete rings of retaining walls are connected into a whole through longitudinal connecting bolts (4) to form a prefabricated retaining wall; n=1,2,3,4..., increasing in sequence.
5. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: In step S2, bolt holes are reserved in the circumferential and longitudinal directions of the prefabricated pipe segments. The prefabricated pipe segments are designed according to the actual engineering conditions to determine the wall thickness, the prefabricated pipe segment height, the number of segments and the size of the holes in the prefabricated pipe segments. The prefabricated pipe segments are assembled into a closed-loop conical wall using bent bolts (3), and the upper and lower adjacent conical walls are longitudinally connected and fixed using tongue-and-groove longitudinal connecting bolts (4), thereby finally forming a conical hollow space wall structure.
6. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: In step S4, the main reinforcement, stirrups and reinforcing bars of the pile foundation are respectively suspended into the hole and manually tied directly in the hole to form a steel cage (9).
7. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: In step S5, when pouring concrete (10), continuous pouring is performed using a conduit, the conduit is connected by a socket and spigot connection, and is sealed by a rubber ring or a rubber plate. The length of each conduit section is 2 m, and the depth of the conduit buried in the concrete is maintained to be no less than 1 m. After the concrete pouring is completed, the conduit is slowly pulled out, and the conduit is repeatedly inserted before being lifted off the concrete surface to avoid hollow piles.
8. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: The opening rate of the prefabricated pipe segment (1) is less than or equal to 40%, and the opening direction is inclined upward, and the angle between the opening direction and the horizontal plane is 10°; the height of the excavated soil in a single section is 300-500 mm.
9. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: The lower diameter of the prefabricated retaining wall (8) is 50-60 mm larger than the upper diameter, ensuring that the upper part is smaller and the lower part is larger; the prefabricated pipe segment (1) has a thickness of 50-60 mm, a weight of 40-60 kg, and a height of 300-500 mm.
10. The method for constructing a conical concrete prefabricated retaining wall artificially dug anti-pulling pile according to claim 1, characterized in that: According to the actual situation on site, each ring of prefabricated retaining wall includes 3-6 prefabricated pipe segments (1); the steel bars are hoisted to the pile holes by lifting equipment and manually tied into steel bar cages (9) in the pile holes; the lifting equipment is a SISINSING small gantry electric crane with a maximum lifting weight of 500 kg.