Shallow covering layer lock catch steel pipe pile cofferdam pile planting construction method

Abstract

The invention discloses a shallow covering layer lock catch steel pipe pile cofferdam pile planting construction method, and particularly relates to the technical field of lock catch steel pipe pile cofferdam pile planting. The method comprises the steps that S1, according to geological data and field investigation conditions, the geology of a geologic layer within a bearing platform range is confirmed, it is confirmed that a bearing platform cofferdam is constructed through a lock catch steel pipe pile cofferdam, and the pile cap cofferdam is constructed through the lock catch steel pipe pile cofferdam; the lock catch steel pipe piles are constructed by matching corner piles and common piles with steel buckle assemblies and additional reinforcing assemblies; and S2, a steel platform frame is arranged at the edge of the foundation pit, water is pumped and excavated to the position below the first ring beam, a first ox horn frame is welded to the corresponding steel pipe pile, the ring beam is assembled on the first bracket, and a second ox horn frame is installed after the ring beam is assembled. When pressure is released into the corner pile and the common pile, at the moment, the first inserting lock catch and the second inserting lock catch of the corner pile are connected and matched with an additional reinforcing assembly to disperse the pressure, gaps between pile bodies are reduced, and an effective waterproof barrier can be formed.

Description

Technical Field

[0001] This application relates to the technical field of pile driving for locked steel pipe pile cofferdams, and more specifically, to a pile driving construction method for a locked steel pipe pile cofferdam in a shallow overburden layer. Background Art

[0002] As an efficient and environmentally friendly temporary water retaining structure, locked steel pipe pile cofferdams are widely used in water conservancy projects, bridge construction, port terminals and other fields. However, during the construction process, in the face of construction environments such as deep water or soft soil, the pile structures set up, without restrictions, often gradually fail as the construction progresses, affecting the construction. After retrieval, the existing application number: CN117822442A discloses an underwater construction method for drilling holes in steel pipe piles on a riverbed without overburden layer, including: S1. Move the weighing ship into position; S2. Install temporary Bailey beams and bridge decks; S3. Measure and set out the positions and install the guiding frame; S4. Lower the steel casing; S5. Position the drilling rig and drill holes; S6. Drive in the steel pipe piles and pour concrete; S7. Pull out the steel casing; and S8. Demolish the temporary Bailey beams, a total of eight steps. Using the weighing ship and the completed steel pipe pile cross beams as the load-bearing main bodies to bear the construction loads of the drilling operation of the drilling rig, a new type of steel pipe pile hole drilling method is formed. Instead of the traditional "fishing method" cantilever construction and the "pile replacement" construction of the waterborne operation platform, it is safer and can provide a large working surface, effectively improving the construction efficiency. It solves the problem of difficult drilling of steel pipe piles caused by the lack of overburden layer on the riverbed of the foundation pit after blasting of the underwater low-pile cap cofferdam or the inclined rock on the slope of the foundation pit after blasting. The inventor found the following problems in the process of implementing this application: During the existing pile driving construction of cofferdams, earth-rock cofferdams or steel sheet pile cofferdams are respectively adopted according to the size of the construction scale. These construction methods with obvious construction limitations will not be affected by the construction environment and geological factors during normal construction. However, in a construction environment with soft geology and rich groundwater, the pile structures set up are easily washed by the water carrying sand and gravel to scour the pile driving of the cofferdam, resulting in the sealing failure of the pile driving of the cofferdam and affecting the construction. Therefore, a pile driving construction method for a locked steel pipe pile cofferdam in a shallow overburden layer is proposed for the above problems. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, this application provides a pile driving construction method for a locked steel pipe pile cofferdam in a shallow overburden layer to solve the problems raised in the above background art.

[0004] To achieve the above object, this application provides the following technical solution: A pile driving for a locked steel pipe pile cofferdam in a shallow overburden layer includes the following steps: S1. According to geological data and on-site investigation, confirm the geology of the geological strata within the bearing platform, confirm that the cofferdam of the bearing platform adopts a lock-pile steel pipe pile cofferdam for construction, and the lock-pile steel pipe piles are constructed with corner piles and ordinary piles in combination with steel buckle components and additional reinforcement components; S2. Set up a steel platform frame at the edge of the foundation pit, pump out water and excavate to a depth below the first ring beam, weld the first bullhorn bracket on the corresponding steel pipe pile, assemble the ring beam on the first corbel, and install the second bullhorn bracket after the ring beam assembly is completed; S3. Pour concrete with a bottom formwork at the gap between the first ring beam and the steel pipe pile, pump out water and excavate to a depth below the second ring beam, and construct the second ring beam and the third ring beam in this way successively; S4. Pump out water and excavate to below the bottom of the bearing platform, and pour a thick concrete cushion; after the strength of the bottom seal concrete reaches the requirement, tie the steel bars of the bearing platform, pour the bottom step of the bearing platform, and backfill sand to below the top of the bottom step of the bearing platform. After the concrete beam construction is completed, fill the water to the top of the bearing platform, remove the third ring beam and the internal support, and construct the top step of the bearing platform; S5. After the concrete of the bearing platform reaches the design strength, remove the formwork, and backfill the soil in the pit to the top of the bearing platform; S6. Remove the internal support system, construct the tower base, backfill the pit to the ground elevation, and pull out the lock-pile steel pipe piles.

[0005] In step S1, according to geological data and on-site investigation, confirm the construction elevation, design water level, maximum water depth, and the bottom elevation of the foundation pit of the bearing platform, finally determine the maximum excavation depth, and then confirm that the geology of the geological strata within the bearing platform is a silty clay layer and a sandstone layer, and confirm that the cofferdam of the bearing platform adopts a lock-pile steel pipe pile cofferdam for construction.

[0006] In step S2, during the construction of the foundation pit, a steel platform frame is successively and progressively set around the foundation pit, and the four sides of the foundation pit are marked and the insertion platform is confirmed. The four sides of the insertion platform are all inserted with corner piles by hammering, and taking the corner piles as the construction points, ordinary piles are symmetrically set.

[0007] In step S2, the first insertion lock of the steel buckle component and the second insertion lock are respectively arranged on both sides of the corner pile and the ordinary pile. When the corner pile is lowered, the first insertion lock of the ordinary pile is connected to the second insertion lock of the corner pile and placed. Then, the installation bases of the additional reinforcement components are respectively arranged on both sides of the top of the corner pile and the ordinary pile, and the insertion block and the insertion shaft are successively installed at the top of the installation base, and the insertion block and the insertion shaft are threadedly connected to cooperate with the steel buckle component for secondary reinforcement.

[0008] In step S2, taking the ordinary pile as the construction base point, pump water and excavate in the foundation pit to a depth below the first ring beam. Install stiffening plates at the corner ends of the first ring beam, weld the first mounting plate of the first bull horn bracket to the corresponding ordinary pile, and weld the first side bracket through the first mounting shaft inserted in the first mounting plate. Then, weld the first support rod to the two first side brackets after they are abutted. Assemble the ring beam on the first bull horn bracket. After the ring beam is assembled, weld a second mounting plate at a distance of m outside the first mounting plate based on the first bull horn bracket, install a second mounting shaft in the second mounting plate, penetrate and weld the second side bracket through the outer end of the second mounting shaft, hoist the second side support rod and place it on the first support rod. Then, continue to move the second support rod, adjust the two ends to be abutted to the second side bracket and weld them, and install the second bull horn bracket.

[0009] In step S3, taking the corner pile as the pouring partition point, pour the first concrete filling and the second concrete filling on both sides of the corner pile in sequence. Pump water and excavate to a depth below the second ring beam, and construct the second ring beam and the third ring beam in the same way. When the construction of the second ring beam and the third ring beam is completed, weld the first bull horn bracket and the second bull horn bracket to the corner ends of the second ring beam and the third ring beam in sequence.

[0010] In step S4, pump water and excavate to below the bottom of the bearing platform, dredge and level the bottom of the foundation pit, place concrete piles at the bottom of the foundation pit, and place the first support frame and the second support frame in a staggered manner at the center of the concrete pile group to divide the concrete pile group into four parts. Taking the concrete piles as the construction base points, pour a concrete cushion on the top. After the strength of the concrete cushion reaches the requirement, install a bearing platform on the concrete cushion, tie the steel bars of the bearing platform, set up formwork, and pour concrete into the formwork to construct the bearing platform. In step S5, after the bearing platform is poured, backfill sand to a position 1 m below the top of the bottom-step bearing platform, pour a 1-m-high concrete beam. After the construction of the concrete beam is completed, fill water to the top of the bearing platform, demolish the third ring beam and the internal support, and construct the top-step bearing platform.

[0011] In step S5, when the concrete of the bearing platform on the concrete cushion reaches the design strength and the formwork is removed, backfill the soil in the foundation pit to the top of the bearing platform at this time and tamp the backfilled soil.

[0012] In step S6, after the backfilled soil is tamped, construct from the bottom to the top at the bottom end of the foundation pit, adopt the constructed support structure and the steel platform frame, and continue to backfill the soil in the foundation pit to the ground elevation. Remove the additional reinforcement components, and then remove the corner piles and the ordinary piles in sequence.

[0013] Technical effects and advantages of the present application: 1. Compared with the prior art, in this method for driving piles in a cofferdam of a shallow-covered layer lock-pile steel pipe pile, a first insertion lock and a second insertion lock of a steel buckle assembly are respectively arranged on both sides of the corner pile and the ordinary pile. When the corner pile is lowered, the first insertion lock of the ordinary pile is connected to the second insertion lock of the corner pile and placed. Then, the installation bases of the additional reinforcement assembly are respectively arranged on both sides of the tops of the corner pile and the ordinary pile. The insertion structure between the installation base and the pile body forms a reinforcement end. When pressure is released into the corner pile and the ordinary pile, at this time, the first insertion lock and the second insertion lock of the corner pile are connected and cooperate with the additional reinforcement assembly to disperse the pressure and reduce the gap between the piles, forming an effective waterproof barrier.

[0014] 2. Compared with the prior art, in this method for driving piles in a cofferdam of a shallow-covered layer lock-pile steel pipe pile, an insertion block and an insertion shaft are successively installed on the top of the installation base, and they are threadedly connected through the insertion block and the insertion shaft, and are fully welded to the pile body to form a rigid joint. The horizontal load can be spread and transmitted to adjacent piles through the insertion shaft, avoiding the problem of lock failure caused by local stress concentration. The insertion lock structure of the steel buckle assembly forms the first shear resistance line of defense, and the insertion block and the insertion shaft of the additional reinforcement assembly form the second shear resistance system through threaded engagement, improving the horizontal bearing capacity of a single pile. Through secondary reinforcement with the steel buckle assembly, a combined structure of a corner pile and an ordinary pile with the steel buckle assembly and the additional reinforcement assembly is adopted. A continuous and airtight barrier is formed through the double insertion lock structure to block the seepage of the muddy soil layer. At the same time, the steel pipe pile embedded in the sandstone layer maintains the overall bending resistance of the pile body through the steel buckle assembly and the additional reinforcement assembly to adapt to the soft-hard alternating geology. Moreover, the lock-pile steel pipe pile forms a continuous retaining wall, avoiding the overflow of slurry during excavation and protecting the stability of the surrounding strata. When there are sensitive buildings at the construction site, the stability of the building can be maintained. Description of the Drawings

[0015] Figure 1 It is a top view structural schematic diagram of the whole of the present application; Figure 2 It is an internal structural schematic diagram of the foundation pit of the present application; Figure 3 It is a top view structural schematic diagram of the corner pile of the present application; Figure 4 Of the present application Figure 2 The structural schematic diagram at A in Figure 5 Of the present application Figure 3 The structural schematic diagram at B in Figure 6 It is a structural schematic diagram of the ring beam of the present application; Figure 7 It is a front view structural schematic diagram of the steel platform frame of the present application.

[0016] The attached drawing reference numerals are: 1, foundation pit; 101, first concrete filling; 102, second concrete filling; 2, corner pile; 201, ordinary pile; 3, steel platform frame; 4, first ox horn frame; 401, first support rod; 402, first side frame; 403, first mounting shaft; 404, first mounting plate; 5, second ox horn frame; 501, second support rod; 502, second side frame; 503, second mounting shaft; 504, second mounting plate; 6, concrete pile; 7, insertion platform; 8, stiffening plate; 9, steel buckle assembly; 10, first support frame; 11, second support frame; 12, concrete cushion; 13, additional reinforcement assembly; 14, insertion block; 15, insertion shaft; 16, mounting base; 17, first insertion lock; 18, second insertion lock; 19, ring beam. Specific implementation manners

[0017] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0018] Embodiment As shown in the attached Figures 1 to 7 drawing, a method for driving piles in a lock-pile steel pipe pile cofferdam with shallow overburden includes the following steps: S1. According to the geological data and on-site investigation, confirm the geology of the geological layer within the range of the bearing platform, and confirm that the lock-pile steel pipe pile cofferdam is used for the construction of the bearing platform cofferdam. The lock-pile steel pipe piles are constructed by using the corner piles 2 and the ordinary piles 201 in cooperation with the steel buckle assembly 9 and the additional reinforcement assembly 13; S2. Set up the steel platform frame 3 at the edge of the foundation pit 1, pump out the water and excavate to a depth below the first ring beam 19. Weld the first ox horn frame 4 on the corresponding steel pipe pile, assemble the ring beam 19 on the first corbel, and install the second ox horn frame 5 after the assembly of the ring beam 19 is completed; S3. Pour concrete with a bottom formwork at the gap between the first layer of ring beam 19 and the steel pipe pile. Pump out the water and excavate to a depth below the second ring beam 19, and construct in the same way for the second ring beam 19 and the third ring beam 19; S4. Pump out the water and excavate to below the bottom of the bearing platform, and pour a thick concrete cushion 12; after the strength of the bottom-sealing concrete reaches the requirement, tie the steel bars of the bearing platform, pour the bottom-step bearing platform, and backfill sand to below the top of the bottom-step bearing platform. After the concrete beam construction is completed, fill the water to the top of the bearing platform, remove the third ring beam 19 and the internal support, and construct the top-step bearing platform; S5. After the concrete of the bearing platform reaches the design strength, remove the formwork, and backfill the soil in the pit to the top of the bearing platform; S6. Demolish the internal support system, construct the tower base, backfill the pit to the ground elevation, and extract the locked steel pipe piles.

[0019] As a preferred embodiment, in step S1, according to geological data and on-site investigation, confirm the construction elevation, design water level, maximum water depth, and the bottom elevation of the foundation pit 1 of the bearing platform. Finally, determine the maximum excavation depth. By confirming the information, maintain the integrity of the construction information to facilitate construction. Then, confirm that the geological layer within the bearing platform is a silty clay layer and a sandstone layer. By confirming that the construction geology information is a silty clay layer and a sandstone layer, confirm the subsequent construction method. When the geology is confirmed to be a silty clay layer and a sandstone layer, the bearing platform cofferdam is constructed using a locked steel pipe pile cofferdam, and the construction method adopted conforms to the silty clay layer and sandstone layer of the construction area investigated.

[0020] As a preferred embodiment, in step S2, during the construction of the foundation pit 1, a steel platform frame 3 is sequentially and progressively arranged around the foundation pit 1. The steel platform frame 3 is arranged on the four sides of the foundation pit 1. Through the progressive construction method, the structure of the steel platform frame 3 continuously moves upward, increasing the floor height to facilitate the construction of equipment through the steel platform frame 3. Moreover, the steel platform frame 3 and the additional reinforcement components 13, etc., adopt a standardized construction method, and its support system can be quickly installed and demolished, enabling the pile body to be reused after extraction to reduce the material cost during construction. Also, draw lines on the four sides of the foundation pit 1 and confirm the insertion platform 7. The four sides of the insertion platform 7 are all driven with corner piles 2 by hammering, and ordinary piles 201 are symmetrically arranged with the corner piles 2 as the construction points. In step S2, the first insertion lock 17 and the second insertion lock 18 of the steel buckle assembly 9 are respectively arranged on both sides of the corner pile 2 and the ordinary pile 201. When the corner pile 2 is lowered, the first insertion lock 17 of the ordinary pile 201 is connected to the second insertion lock 18 of the corner pile 2 and placed. Then, the mounting bases 16 of the additional reinforcement assembly 13 are respectively arranged on both sides of the tops of the corner pile 2 and the ordinary pile 201. The insertion structure between the mounting base 16 and the pile body forms a reinforcement end, so that when pressure is released into the corner pile 2 and the ordinary pile 201, at this time, the first insertion lock 17 and the second insertion lock 18 of the corner pile 2 are connected and cooperate with the additional reinforcement assembly 13 to disperse the pressure and reduce the gap between the piles, forming an effective waterproof barrier. Then, the insertion block 14 and the insertion shaft 15 are successively installed on the top of the mounting base 16, and are threadedly connected through the insertion block 14 and the insertion shaft 15, and are connected to the pile body by full welding to form a rigid joint, which can spread the stress of the horizontal load through the insertion shaft 15 to the adjacent 3 piles, avoiding the problem of lock failure caused by local stress concentration. The insertion lock structure of the steel buckle assembly 9 forms the first shear resistance line of defense, and the insertion block 14 and the insertion shaft 15 of the additional reinforcement assembly 13 form the second shear resistance system through threaded engagement, improving the horizontal bearing capacity of a single pile. Through secondary reinforcement with the steel buckle assembly 9, the combined structure of the corner pile 2 and the ordinary pile 201 with the steel buckle assembly 9 and the additional reinforcement assembly 13 forms a continuous and airtight barrier through the double insertion lock structure to block the seepage of the muddy soil layer. At the same time, the steel pipe piles embedded in the sandstone layer maintain the overall bending resistance of the pile body through the steel buckle assembly 9 and the additional reinforcement assembly 13 to adapt to the soft-hard alternating geology, and the lock steel pipe piles form a continuous retaining wall to avoid the overflow of mud during excavation and protect the stability of the surrounding strata. When there are sensitive buildings at the construction site, the stability of the building can be maintained; Taking the ordinary pile 201 as the construction reference point, pump water and excavate to a depth below the first ring beam 19 in the foundation pit 1, and install stiffening plates 8 at the corner ends of the first ring beam 19. Form an initial support framework by welding the first horn-shaped frame 4, and cooperate with the stiffening plate 8 to enhance the joint stiffness. Weld the first mounting plate 404 of the first horn-shaped frame 4 to the corresponding ordinary pile 201. The first horn-shaped frame 4 takes the ordinary pile 201 as the reference point, and forms a triangular truss by welding the first support rod 401 and the side frame 402 to disperse the stress generated during the excavation of the foundation pit 1, reduce the stress concentrated in the local area, and the first mounting shaft 403 inserted in the first mounting plate 404 is welded to connect the first side frame 402, and the first support rod 401 is attached to and welded to the two first side frames 402. Assemble the ring beam 19 on the first corbel. After the ring beam 19 is assembled, based on the first horn-shaped frame 4, complete the welding of the upper ring beam 19 and the corresponding horn-shaped frame before each layer of pumping and excavation. Use the ring beam 19 to transfer the lateral earth pressure to the steel pipe pile to avoid the overall instability of the foundation pit 1. Weld the second mounting plate 504 at a position 2 m outside the first mounting plate 404, and install the second mounting shaft 503 in the second mounting plate 504. The outer end of the second mounting shaft 503 penetrates and welds the second side frame 502, and hoist the second side support rod and place it on the first support rod 401. Continue to move the second support rod 501, adjust the two ends to be attached to and welded to the second side frame 502, and install the second horn-shaped frame 5. And a second mounting plate 504 is provided at an extension of 2 m of the second horn-shaped frame to expand the support coverage range and match the increased earth pressure distribution after deep excavation.

[0021] As a preferred implementation method, in step S3, taking the corner pile 2 as the pouring partition point, pour the first concrete filling 101 and the second concrete filling 102 on both sides of the corner pile 2 in sequence. Pour the first concrete filling 101 and the second concrete filling 102 into the gap of the ring beam 19 to form a rigid retaining wall, reduce the risk of cofferdam deformation, pump water and excavate to a position below the second ring beam 19, and construct in this way for both the second ring beam 19 and the third ring beam 19. When the construction of the second ring beam 19 and the third ring beam 19 is completed, weld the first horn-shaped frame 4 and the second horn-shaped frame 5 at the corner ends of the second ring beam 19 and the third ring beam 19 in sequence.

[0022] As a preferred implementation method, in step S4, pump water and excavate to the bottom of the pile cap, dredge and level the bottom of the foundation pit 1, place the concrete pile 6 at the bottom of the foundation pit 1, and staggeredly place the first support frame 10 and the second support frame 11 at the center of the concrete pile (6) group to divide the concrete pile 6 group into four parts. Taking the concrete pile 6 as the construction reference point, then pour the concrete cushion 12 at the top. After the strength of the concrete cushion 12 reaches the requirement, install the pile cap on the concrete cushion 12, bind the pile cap steel bars, set up the formwork, pour into the formwork, and carry out the pile cap construction; In step S4, after the pouring of the foundation is completed, sand is backfilled to 1m below the top of the bottom foundation, and a 1m high concrete beam is poured. After the foundation is constructed, sand is backfilled in stages and compacted, combined with the water filling and compaction process to reduce the later ground settlement. After the construction of the concrete beam is completed, water is poured to the top of the foundation, the third ring beam 19 and the internal support are removed, and the top foundation is constructed.

[0023] As a preferred embodiment, in step S5, when the pedestal concrete on the concrete cushion layer 12 reaches the designed strength and the formwork is removed, the soil is backfilled into the foundation pit 1 to the top of the pedestal and the backfill soil is compacted to complete the treatment of the foundation pit. At this time, even if the inside of the foundation pit continues to seep water, affecting the construction, a ring beam 19 is set on the inner contact surface of the ordinary pile 201 and a three-dimensional support structure is formed by the first bullhorn frame and the second bullhorn frame, so that the flexible cofferdam is reinforced by a rigid internal support. Even if the foundation pit is in a high water level and in soft and hard alternating strata, the stability of the construction can still be maintained.

[0024] As a preferred embodiment, in step S6, after the backfill soil is compacted, construction is carried out from the bottom to the top with the bottom of the foundation pit 1, using the constructed support structure and steel platform frame 3, and continuing to backfill the soil into the foundation pit 1 to the ground elevation, removing the additional reinforcement assembly 13, and removing the corner piles 2 and ordinary piles 201 in turn.

[0025] The working process of this application is as follows: first, according to the geological data and on-site investigation, the geological layers within the range of the cap are confirmed, and the cap cofferdam is confirmed to be constructed with locking steel pipe pile cofferdams. The locking steel pipe piles are constructed with angle piles 2 and ordinary piles 201 in combination with steel buckle components 9 and additional reinforcement components 13; A steel platform frame 3 is set at the edge of the foundation pit 1, and water is pumped to the depth below the first ring beam 19, and the first horn frame 4 is welded on the corresponding steel pipe pile, and the ring beam 19 is assembled on the first corbel. After the ring beam 19 is assembled, the second horn frame 5 is installed; A bottom form is set at the gap between the first ring beam 19 and the steel pipe pile to pour concrete, and water is pumped out to the bottom of the second ring beam 19. The second and third ring beams 19 are constructed in this way; Pump water to the bottom of the cap and pour thick concrete cushion 12; after the strength of the bottom concrete reaches the requirement, tie the cap steel bars, pour the bottom cap, and backfill sand to the bottom of the bottom cap. After the concrete beam is constructed, pour water to the top of the cap, remove the third ring beam 19 and the inner support, and construct the top cap; After the foundation concrete reaches the designed strength, the formwork is removed, the pit is backfilled to the top of the foundation, the internal support system is removed, the tower base is constructed, the pit is backfilled to the ground elevation, and the locking steel pipe piles are removed. The above is the working principle of this shallow covering layer locking steel pipe pile cofferdam pile planting method.

Claims

1. A method for driving piles of a cofferdam made of lock steel pipe piles with shallow overburden, characterized in that , including the following steps: S1. According to geological data and on-site investigation, confirm the geology of the geological layer within the bearing platform, confirm that the cofferdam of the bearing platform uses a locked steel pipe pile cofferdam for construction, and the locked steel pipe piles are constructed with corner piles (2) and ordinary piles (201) in cooperation with steel buckle components (9) and additional reinforcement components (13); S2. Set up a steel platform frame (3) at the edge of the foundation pit (1), pump water and excavate to a depth below the first ring beam (19), weld a first ox horn bracket (4) on the corresponding steel pipe pile, assemble the ring beam (19) on the first corbel, and install a second ox horn bracket (5) after the ring beam (19) is assembled; S3. Pour concrete with a bottom formwork at the gap between the first layer of ring beam (19) and the steel pipe pile, pump water and excavate to a depth below the second ring beam (19), and construct in the same way for the second ring beam (19) and the third ring beam (19); S4. Pump water and excavate to below the bottom of the bearing platform, and pour a thick concrete cushion (12); after the strength of the bottom seal concrete reaches the requirement, tie the steel bars of the bearing platform, pour the bottom step of the bearing platform, and backfill sand to below the top of the bottom step of the bearing platform. After the concrete beam construction is completed, fill the water to the top of the bearing platform, remove the third ring beam (19) and the internal support, and construct the top step of the bearing platform; S5. After the concrete of the bearing platform reaches the design strength, remove the formwork, and backfill the soil in the pit to the top of the bearing platform; S6. Remove the internal support system, construct the tower base, backfill the pit to the ground elevation, and pull out the locked steel pipe piles.

2. The pile driving of the shallow covering layer lock steel pipe pile cofferdam according to claim 1, wherein: In step S1, according to geological data and on-site investigation, confirm the construction elevation, design water level, maximum water depth, and the bottom elevation of the foundation pit (1) of the bearing platform, finally determine the maximum excavation depth, and then confirm that the geology of the geological layer within the bearing platform is a silty clay layer and a sandstone layer, and confirm that the cofferdam of the bearing platform uses a locked steel pipe pile cofferdam for construction.

3. A method for driving piles of a shallow covering layer lock steel pipe pile cofferdam according to claim 1, characterized in that: In step S2, during the construction of the foundation pit (1), a steel platform frame (3) is sequentially and progressively set around the foundation pit (1), and the insertion platform (7) is marked and confirmed on the four sides of the foundation pit (1). The four sides of the insertion platform (7) are all inserted with corner piles (2) by hammering, and ordinary piles (201) are symmetrically set with the corner piles (2) as the construction points.

4. A method for driving piles in a cofferdam of a shallow overburden lock-bolt steel pipe pile according to claim 1, characterized in that: In step S2, the first insertion lock (17) and the second insertion lock (18) of the steel buckle component (9) are respectively arranged on both sides of the corner pile (2) and the ordinary pile (201). When the corner pile (2) is lowered, the first insertion lock (17) of the ordinary pile (201) is connected to the second insertion lock (18) of the corner pile (2) and placed. Then, the installation bases (16) of the additional reinforcement component (13) are respectively arranged on both sides of the tops of the corner pile (2) and the ordinary pile (201), and the insertion blocks (14) and the insertion shafts (15) are sequentially installed on the tops of the installation bases (16), and the insertion blocks (14) and the insertion shafts (15) are threadedly connected to cooperate with the steel buckle component (9) for secondary reinforcement.

5. A method for driving piles in a cofferdam of a shallow overlying layer lock-pile steel pipe pile according to claim 4, characterized in that: In step 2, taking the common pile (201) as the construction base point, water is pumped out in the foundation pit (1) to a depth below the first ring beam (19), and a stiffening plate (8) is installed at the corner end of the first ring beam (19). The first mounting plate (404) of the first horn frame (4) is welded to the corresponding common pile (201), and the first mounting shaft (403) inserted in the first mounting plate (404) is welded to the first side frame (402), and the first support rod (401) and the two first side frames (402) are attached and welded to the first horn frame (4). Assemble the ring beam (19). After the ring beam (19) is assembled, the first horn frame (4) is used as the basis. A second mounting plate (504) is welded 2 m outside the first mounting plate (404), and a second mounting shaft (503) is installed in the second mounting plate (504). The second side frame (502) is penetrated and welded with the external end of the second mounting shaft (503). The second side support rod is hoisted and placed on the first support rod (401). The second support rod (501) is continuously moved, and the two ends are adjusted to fit with the second side frame (502) and welded, and the second horn frame (5) is installed.

6. A method for driving piles of a shallow overburden lock steel pipe pile cofferdam according to claim 1, characterized in that: In step S3, the corner pile (2) is used as a casting dividing point, and the first concrete filler (101) and the second concrete filler (102) are cast in sequence on both sides of the corner pile (2), and water is pumped out to the bottom of the second ring beam (19). The second ring beam (19) and the third ring beam (19) are constructed in this way. When the construction of the second ring beam (19) and the third ring beam (19) is completed, the first bullhorn bracket (4) and the second bullhorn bracket (5) are welded in sequence at the corner ends of the second ring beam (19) and the third ring beam (19).

7. A method for driving piles in a cofferdam of a shallow overlying layer lock-bolt steel pipe pile according to claim 1, characterized in that: In step S4, water is pumped out to excavate below the cap, the bottom of the foundation pit (1) is silted and leveled, concrete piles (6) are placed at the bottom of the foundation pit (1), and a first support frame (10) and a second support frame (11) are placed in a staggered manner at the center of the concrete pile (6) group, so that the concrete pile (6) group is divided into four parts. The concrete pile (6) is used as a construction base point, and a concrete cushion layer (12) is then poured at the top. After the strength of the concrete cushion layer (12) reaches the required level, a cap is installed on the concrete cushion layer (12), and the cap reinforcement is tied. A template is set, and pouring is performed into the template to carry out the cap construction.

8. A method for driving piles in a cofferdam of a shallow overburden lock-bolt steel pipe pile according to claim 1, characterized in that: In step S4, after the cap is poured, sand is backfilled to 1 m below the top of the bottom cap, and a 1 m high concrete beam is poured. After the concrete beam is constructed, water is poured to the top of the cap, the third ring beam (19) and the inner support are removed, and the top cap is constructed.

9. A method for driving piles in a cofferdam of a shallow overlying layer lock-fastened steel pipe pile according to claim 1, characterized in that: In step S5, when the cap concrete on the concrete cushion layer (12) reaches the designed strength and the formwork is removed, soil is backfilled into the foundation pit (1) to the top of the cap and the backfilled soil is compacted.

10. A method for driving piles in a cofferdam of a shallow-overburden lock-pile steel pipe pile according to claim 1, characterized in that: In step S6, after the backfill soil is tamped, construction is carried out from the bottom to the top of the bottom end of the foundation pit (1). The constructed support structure and the steel platform frame (3) are used, and backfill soil is continuously filled into the foundation pit (1) until the ground elevation. The additional reinforcement assembly (13) is removed, and the corner piles (2) and the ordinary piles (201) are removed in sequence.

Images