Open caisson post-installation type shear key structure and construction method thereof

Abstract

The invention discloses an open caisson post-installation type shear key structure and a construction method thereof.The open caisson post-installation type shear key structure comprises an open caisson wall, a shear key structure is arranged on the side portion of the open caisson wall, a sliding groove is formed in the open caisson wall, a downward-putting connecting rod is arranged in the sliding groove, and the bottom of the downward-putting connecting rod is connected with the shear key structure; by the adoption of the post-installation type shear key structure of the open caisson and the construction method thereof, the dead zone of the open caisson is effectively reduced, and the soil taking efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and in particular relates to a caisson rear-mounted shear key structure and a construction method thereof. Background Art

[0002] Caisson is a shaft-shaped structure. It is excavated in the well, and sinks to the designed elevation by relying on its own gravity to overcome the friction of the well wall. Then, the bottom is sealed with concrete and the well hole is filled to make it the foundation of bridge piers or other structures. Caisson is widely used in bridge foundations, anchorages, and water supply and drainage projects due to its high overall rigidity and good integrity.

[0003] At present, the first section of a large caisson foundation often needs to be equipped with a thick shear key structure as a force transmission structure between the bottom concrete and the caisson wall. The existing shear key structure is integrally formed with the caisson body, that is, the shear key structure has a certain volume. There is a large blind area when the caisson is lowered to take soil, which makes it difficult to take soil under the shear key structure and at the bottom of the caisson blade foot, making it difficult to sink the caisson, and the workers' construction efficiency is low, affecting construction efficiency. If soil is taken blindly, the geological strength below the caisson will be reduced, increasing construction risks.

[0004] The invention patent with publication number CN 118007687A disclosed on May 10, 2024 a method for sinking and taking soil from a super-large caisson. The method includes: dividing the caisson into a core area and a remaining area, dividing the caisson into multiple areas, determining the soil taking area and the soil taking blind area of ​​the well hole, determining the soil taking depth of the well hole soil taking area, taking soil in layers and zones across the entire cross section of the caisson, reserving mud suction holes and water injection holes through the caisson structure, using high-pressure water jets to destroy the soil in the blind area, and adjusting the soil taking progress based on the caisson foundation posture monitoring and structural stress monitoring data. This construction method cannot solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a caisson rear-mounted shear key structure and a construction method thereof, which can effectively reduce the blind area of ​​the caisson and improve the efficiency of earthwork.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The rear-mounted shear key structure of the caisson comprises a caisson wall, wherein the shear key structure is arranged on the side of the caisson wall, a slide groove is arranged on the caisson wall, a lowering connecting rod is arranged in the slide groove, and the bottom of the lowering connecting rod is connected to the shear key structure.

[0008] The caisson wall is provided with a cavity, the shear key structure is located on one side of the cavity, the cavity is provided with transverse reinforcement of the caisson wall, and the shear key structure is provided with a steel mesh; the lowering connecting rod includes an intermediate steel rod, the intermediate steel rod is located in a slide groove, a steel plate is fixedly connected to the bottom of the intermediate steel rod, and the transverse reinforcement and steel plate of the caisson wall are both fixedly connected to the steel mesh.

[0009] A side steel panel is provided on the side of the shear key structure, a pin is connected to the bottom end of the steel mesh and the side steel panel, a hook is provided on the top end of the side steel panel, and the hook is located on one side of the end of the top template.

[0010] A top template is provided on the top of the shear key structure, and a casting hole and a vibrating hole are provided on the top template; the top template is consistent in height with the top of the cavity, and the bottom of the side steel panel is in contact with the bottom of the cavity.

[0011] A rubber sliding strip is provided on the side of the middle steel rod, and the end of the rubber sliding strip is in contact with the inner side of the sliding groove.

[0012] The slide groove connects the cavity and the top of the caisson wall, and the slide groove is a "["-shaped structure.

[0013] The ends of the well wall transverse reinforcements are provided with sleeves, and the well wall transverse reinforcements and the reinforcement mesh are connected through the sleeves.

[0014] The steel mesh comprises transverse steel bars, vertical steel bars and circumferential steel bars, and the steel mesh forms a mesh structure.

[0015] The construction method of the caisson rear-mounted shear key structure comprises the following steps:

[0016] Step 1: The chute is extended section by section as the height of the caisson increases to the top of the caisson;

[0017] Step 2: After the caisson is sunk into place, the concrete on the inner side of the caisson wall corresponding to the installation position of the shear key structure is roughened to expose the transverse steel sleeve of the wall;

[0018] Step 3: Lower the shear key structure along the slideway into place by lowering the connecting rod, and connect the transverse steel bars of the steel mesh with the transverse steel sleeves of the well wall;

[0019] Step 4: Lower the guide tube to the casting hole, cast high-grade early-strength concrete into the shear key structure, vibrate and compact it in the vibration hole, and cast the shear key structure and the caisson wall into a whole;

[0020] Step 5: After the concrete strength reaches the requirement, pour the bottom concrete.

[0021] The technical effects of the present invention are as follows: the rear-installed shear key structure of the caisson of the present invention is adopted, the shear key structure is in the form of post-installation, steel plates and the like are used as templates for pouring concrete for the shear key structure, the steel mesh is connected to the steel bars of the well wall and concrete is poured to form a shear key structure, which can effectively exert the load transfer function of the shear key structure; the post-installation form of the shear key structure has a simple structure, and there is no blind spot of the shear key structure when taking soil from the caisson, which does not affect the soil taking and foundation clearing construction of the caisson, while increasing the area of ​​the soil takeable area, greatly increasing the construction efficiency, reducing the risk of soil taking construction in the blind spot of the caisson, and realizing the construction steps of pouring the bottom concrete of the shear key structure after the caisson sinks into place, which does not affect its use as a force transmission structure after the bottom is sealed; the installation of the shear key structure and the foundation clearing can be carried out in a continuous manner, and high-grade early-strength concrete is used, which does not occupy the key construction line and has little impact on the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] This specification includes the following drawings, which show the following contents:

[0023] Figure 1 It is a structural schematic diagram of the rear-mounted shear key structure of the caisson of the present invention;

[0024] Figure 2 It is a structural schematic diagram of the shear key structure of the present invention;

[0025] Figure 3 It is a structural schematic diagram of the lower connecting rod and the slide groove of the present invention;

[0026] Figure 4 It is a schematic cross-sectional view of a steel mesh of the present invention;

[0027] Figure 5 It is a construction flow chart of the present invention.

[0028] The markings in the figure are: 1-caisson wall, 11-transverse reinforcement of the wall; 12, cavity; 13-sleeve; 2-lowering connecting rod; 21-rubber sliding strip; 22-middle steel rod; 23-steel plate; 3-shear key structure; 31-steel mesh; 311-transverse reinforcement; 312-vertical reinforcement; 313-circumferential reinforcement; 32-side steel panel; 33-top template, 34-casting hole; 35-vibration hole; 36-pin shaft; 37-hook; 4-slide. DETAILED DESCRIPTION

[0029] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and facilitating their implementation.

[0030] like Figures 1 to 3As shown, the rear-mounted shear key structure of the caisson includes a caisson wall 1, a shear key structure 3 arranged on the side of the caisson wall 1, a slide groove 4 is provided on the caisson wall 1, a lowering connecting rod 2 is provided in the slide groove 4, and the bottom of the lowering connecting rod 2 is connected to the shear key structure 3.

[0031] The slide groove 4 serves as a sliding channel and a limiting device for lowering the connecting rod 2. The lowering connecting rod 2 is used to lower the shear key structure 3. The shear key structure 3 is connected to the lowering connecting rod 2 to realize the separate formation of the shear key structure 3 and the first-section caisson structure. During the construction operation, the first-section caisson structure can be constructed in advance. Since there is no visual obstruction of the shear key structure 3 and no blind spot for soil excavation, the soil excavation efficiency is greatly improved. Subsequently, the shear key structure 3 is lowered to the caisson wall 1 by using the lowering connecting rod 2 to realize the subsequent construction of the shear key structure 3. Therefore, the shear key structure 3 and the lowering connecting rod 2 can be prefabricated in the factory and installed on site, which greatly improves the prefabrication and assembly rate of the caisson structure.

[0032] like Figure 3 As shown, the caisson wall 1 is provided with a cavity 12, the shear key structure 3 is located on one side of the cavity 12, the cavity 12 is provided with a well wall transverse steel bar 11, and the shear key structure 3 is provided with a steel mesh 31; the lowering connecting rod 2 includes an intermediate steel rod 22, the intermediate steel rod 22 is located in the slide 4, the bottom of the intermediate steel rod 22 is fixedly connected with a steel plate 23, and the well wall transverse steel bar 11 and the steel plate 23 are both fixedly connected to the steel mesh 31. The lowering connecting rod 2 is used to be inserted into the slide 4, and it is composed of rubber sliding strips 21 on both sides and the intermediate steel rod 22 and the steel plate 23. The cross section of the lowering connecting rod 2 is a T-shaped structure, and the intermediate steel rod 22 is welded to the steel plate 23. The intermediate steel rod 22 is the main structure of the lowering connecting rod 2, and the steel plate 23 welded at the bottom thereof is used to form a connection with the shear key structure 3, and the steel plate 23 is welded to the lower steel mesh 31, so that the lowering connecting rod 2 and the shear key structure 3 are connected as a whole. The cavity 12 is formed by roughening the caisson wall 1. The cavity 12 is set to expand the connection range with the caisson wall 1 without changing the volume of the shear key structure 3, so that the concrete can produce a better consolidation effect, the connection between the shear key structure 3 and the caisson wall 1 is more firm, and the bottom concrete strength is higher. After the concrete in the shear key structure 3 is consolidated, the steel mesh 31 forms a part of the concrete structure, which can disperse and transfer the stress inside the concrete, prevent or reduce the generation and development of cracks, thereby improving the overall performance and durability of the shear key structure 3 and the bottom concrete, and avoiding the shear key structure 3 from breaking and being damaged when transmitting force.

[0033] like Figure 3As shown, a side steel panel 32 is provided on the side of the shear key structure 3, a pin 36 is connected between the bottom end of the steel mesh 31 and the side steel panel 32, a hook 37 is provided on the top of the side steel panel 32, and the hook 37 is located on one side of the end of the top template 33. In the above structure, the side steel panel 32 can rotate around the pin 36, and the hook 37 is provided on the top to be fixed on the steel mesh 31. After the shear key structure 3 is lowered into place, the hook 37 can be released to allow the side steel panel 32 to rotate around the pin 36, leaving a certain space for manually connecting the well wall transverse steel bar 11 with the sleeve 13 of the steel mesh 31; after the side steel panel 32 and the top template 33 are hung with the hook 37, the side steel panel 32 is used as a side template for pouring concrete.

[0034] like Figure 3 As shown, a top template 33 is provided on the top of the shear key structure 3, and a casting hole 34 and a vibrating hole 35 are provided on the top template 33; the top template 33 is at the same height as the top of the cavity 12, and the bottom of the side steel panel 32 abuts against the bottom of the cavity 12. In the above structure, the top template 33 and the side steel panel 32 close the internal space of the shear key structure 3, which is conducive to the consolidation and molding of the concrete in the shear key structure 3, and at the same time avoids leakage during concrete pouring. The casting hole 34 is used for the conduit to pour concrete into the inner cavity of the shear key structure 3, and the vibrating hole 35 is used for the vibrating rod to enter to eliminate defects such as bubbles in the concrete, thereby ensuring the performance of the concrete structure.

[0035] like Figure 2 As shown, a rubber sliding strip 21 is provided on the side of the middle steel rod 22, and the end of the rubber sliding strip 21 contacts the inner side of the slide slot 4. The rubber sliding strips 21 on both sides of the middle steel rod 22 serve as the sliding elements for the lowering connecting rod 2 to slide downward along the slide slot 4, and have a limiting effect on the middle steel rod 22 located in the slide slot 4, so that the middle steel rod 22 is aligned, thereby ensuring that the lowered shear key structure 3 is in a stable lowering posture and accurately installed.

[0036] like Figure 1 and Figure 2 As shown, the slide 4 connects the cavity 12 and the top of the caisson wall 1, and the slide 4 is a "["-shaped structure. The "["-shaped slide 4 structure has an open side, which is convenient for the steel plate 23 to pass through and has a reliable limiting effect. The slide 4 can be made of channel steel or PVC material. When the steel structure is used, the upper and lower sections of the slide 4 are connected by butt welding as the caisson is increased in height and length; when made of PVC material, the upper and lower sections of the slide 4 can be glued at the joint, or a "["-shaped sleeve 13 can be set outside the joint, and the upper and lower sections of the slide 4 are glued or fixed to the sleeve 13 with screws.

[0037] like Figure 3As shown, a sleeve 13 is provided at the end of the shaft wall transverse steel bar 11, and the shaft wall transverse steel bar 11 and the steel mesh 31 are connected through the sleeve 13. The shaft wall transverse steel bar 11 and the transverse steel bar 311 of the steel mesh 31 are connected through the sleeve 13, which makes the connection between the steel bars easier, greatly improves the efficiency of the workers at the construction site, and compared with the welding method, a lot of steel can be saved when connecting the steel bars, and the connection quality will not be affected.

[0038] like Figure 3 As shown, the steel mesh 31 includes transverse steel bars 311, vertical steel bars 312 and circumferential steel bars 313, and the steel mesh 31 forms a mesh structure. The steel mesh 31 is a mesh structure composed of transverse steel bars 311, vertical steel bars 312, circumferential steel bars 313, etc. The steel bars inside the steel mesh 31 are connected by welding, sleeve 13 connection or welding tube extension. The mesh structure formed by the steel mesh 31 greatly improves the structural performance of the shear key structure 3.

[0039] The construction method of the caisson rear-mounted shear key structure comprises the following steps:

[0040] Step 1: The chute 4 is extended section by section to the top of the caisson as the height of the caisson increases;

[0041] Step 2: After the caisson is sunk into place, the concrete inside the caisson wall 1 corresponding to the installation position of the shear key structure 3 is roughened to expose the sleeve 13 of the transverse reinforcement 11 of the wall;

[0042] Step 3: lower the shear key structure 3 along the slide 4 into place by lowering the connecting rod 2, and connect the transverse steel bars 311 of the steel mesh 31 with the sleeves 13 of the transverse steel bars 11 of the well wall;

[0043] Step 4: lower the conduit to the casting hole 34 to cast high-grade early-strength concrete into the shear key structure 3, vibrate and compact it in the vibration hole 35, and cast the shear key structure 3 and the caisson wall 1 into a whole;

[0044] Step 5: After the concrete strength reaches the requirement, pour the bottom concrete.

[0045] The rear-mounted shear key has a simple structure, and its size and shape can be flexibly set according to the size of the caisson structure (circular, square, multi-compartment, etc.), and can be applied to caissons with various shapes such as rectangular and arc-shaped compartment structures. For compartment-shaped caissons, it can be made into an integral or multiple block forms according to the size of the caisson compartments. A single compartment can be divided into multiple shear key structures 3, and each shear key structure 3 can be connected after installation, which is flexible to manufacture and has wide applicability. The number of chutes 4, lowered connecting rods 2, casting holes 34, and vibrating holes 35 is not restricted. One shear key structure 3 can be provided with one or more chutes 4, lowered connecting rods 2, casting holes 34, or vibrating holes 35.

[0046] The shear key structure of the caisson is installed afterward, and the shear key structure 3 is installed afterward, and steel plates and the like are used as templates for pouring concrete for the shear key structure 3. The steel mesh 31 is connected to the steel bars of the well wall and then concrete is poured to form the shear key structure 3, which can effectively play the load transfer function of the shear key structure 3; the shear key structure 3 is installed afterward, and the structure is simple. There is no blind spot of the shear key structure 3 when taking soil from the caisson, which does not affect the soil taking and foundation clearing construction of the caisson. At the same time, the area of ​​the soil takeable area is increased, which greatly increases the construction efficiency, reduces the risk of soil taking construction in the blind spot of the caisson, and realizes the construction step of pouring the bottom concrete of the shear key structure 3 after the caisson sinks into place, which does not affect its use as a force transmission structure after the bottom is sealed; the installation and foundation clearing of the shear key structure 3 can be carried out in a flowing manner, and high-grade early-strength concrete is used, which does not occupy the key construction line and has little impact on the construction period.

[0047] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A shear key structure installed after caisson, characterized in that: The invention comprises a caisson wall (1), wherein the shear key structure (3) is arranged on the side of the caisson wall (1), a slide groove (4) is arranged on the caisson wall (1), a lowering connecting rod (2) is arranged in the slide groove (4), and the bottom of the lowering connecting rod (2) is connected to the shear key structure (3).

2. The rear-mounted shear key structure for caisson according to claim 1, characterized in that: The caisson wall (1) is provided with a cavity (12), the shear key structure (3) is located on one side of the cavity (12), the cavity (12) is provided with a caisson wall transverse steel bar (11), and the shear key structure (3) is provided with a steel mesh (31); the lowering connecting rod (2) includes an intermediate steel rod (22), the intermediate steel rod (22) is located in a slide groove (4), a steel plate (23) is fixedly connected to the bottom of the intermediate steel rod (22), and the caisson wall transverse steel bar (11) and the steel plate (23) are both fixedly connected to the steel mesh (31).

3. The rear-mounted shear key structure for caisson according to claim 2, characterized in that: The side of the shear key structure (3) is provided with a side steel panel (32), the bottom end of the steel mesh (31) and the side steel panel (32) are connected by a pin shaft (36), the top end of the side steel panel (32) is provided with a hook (37), and the hook (37) is located on one side of the end of the top template (33).

4. The rear-mounted shear key structure for caisson according to claim 3, characterized in that: A top template (33) is provided on the top of the shear key structure (3), and a casting hole (34) and a vibration hole (35) are provided on the top template (33); the top template (33) is at the same height as the top of the cavity (12), and the bottom of the side steel panel (32) is in contact with the bottom of the cavity (12).

5. The rear-mounted shear key structure for caisson according to any one of claims 2 to 4, characterized in that: A rubber sliding strip (21) is provided on the side of the middle steel rod (22), and the end of the rubber sliding strip (21) is in contact with the inner side of the sliding groove (4).

6. The rear-mounted shear key structure for caisson according to claim 5, characterized in that: The slide groove (4) connects the cavity (12) and the top of the caisson wall (1), and the slide groove (4) is a "["-shaped structure.

7. The rear-mounted shear key structure for caisson according to claim 5, characterized in that: The end of the shaft wall transverse steel bar (11) is provided with a sleeve (13), and the shaft wall transverse steel bar (11) and the steel mesh (31) are connected via the sleeve (13).

8. The rear-mounted shear key structure for caisson according to claim 7, characterized in that: The steel mesh (31) comprises transverse steel bars (311), vertical steel bars (312) and annular steel bars (313), and the steel mesh (31) forms a mesh structure.

9. A construction method for a post-caisson installation shear key structure, characterized in that: The following steps are involved: Step 1: The chute (4) is extended section by section as the height of the caisson increases to the top of the caisson; Step 2: After the caisson is sunk into place, the concrete on the inner side of the caisson wall (1) corresponding to the installation position of the shear key structure (3) is roughened to expose the sleeve (13) of the transverse reinforcement (11) of the wall; Step 3: lowering the shear key structure (3) along the slide groove (4) into place by lowering the connecting rod (2), and connecting the transverse steel bars (311) of the steel mesh (31) with the sleeves (13) of the transverse steel bars (11) of the shaft wall; Step 4: lower the conduit to the casting hole (34) to cast high-grade early-strength concrete into the shear key structure (3), vibrate and compact it in the vibration hole (35), and cast the shear key structure (3) and the caisson wall (1) into a whole; Step 5: After the concrete strength reaches the requirement, pour the bottom concrete.

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