A caisson shear key structure and construction method thereof

Abstract

The present invention discloses a caisson shear key structure, including a plurality of shear key structural units, which are arranged on the inner side of the first section of the steel shell caisson. The plurality of shear key structural units overlap each other to form a caisson shear key structure. The shear key structural units include an inclined steel plate, a vertical steel plate and a ""-shaped steel shell plate. The inner side of the first section of the steel shell caisson is recessed inward to form a step-shaped notch that is small at the top and large at the bottom. The ""-shaped steel shell plate is fixed to the top and upper part of the step-shaped notch. The inclined steel plate is connected to the inner side and the vertical steel plate of the first section of the steel shell caisson through a connecting shaft. The upper end of the vertical steel plate is connected to the lower end of the ""-shaped steel shell plate through a soft structure. The inclined steel plate and the vertical steel plate are driven to open or close by a driving mechanism. The shear key structure and construction method of the present invention can effectively reduce the blind area of ​​the caisson, improve the efficiency and safety of underwater earthwork, and do not affect its use as a force transmission structure after the bottom is sealed.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and more specifically, to a caisson shear key structure and a construction method thereof. Background Art

[0002] As a foundation form, caisson is widely used in bridge foundations, anchorages, and water supply and drainage projects due to its high overall stiffness and good integrity. In recent years, with the rapid development of large-span bridge construction, many caisson foundations with a span of 100 meters have been built, such as the south anchorage caisson foundation of the Oujiang Beikou Bridge, and the caissons of the 5# and 6# piers of the Changtai Yangtze River Bridge. The first section of the steel caisson of a large caisson foundation often requires a thicker shear key as a force transmission structure between the bottom concrete and the caisson wall. The existence of the shear key leads to a large blind area when taking soil underwater in the well. Taking the 5# pier foundation of the Changtai Yangtze River Bridge as an example, the shear key blind area accounts for up to 15.2% of the cross-sectional area of ​​the caisson. The shear key blind area makes it difficult to take soil under the shear key and the blade foot. The soil taking depth is often increased to form a "pot bottom excavation" to take soil from the blind area; but blindly increasing the soil taking depth and forming a "pot bottom excavation" will lead to insufficient burial depth of the blade foot, which is easy to cause the caisson to sink suddenly and tilt beyond the limit, seriously endangering construction safety. Therefore, it is urgent to design a new caisson shear key structure to solve the above technical problems. Summary of the invention

[0003] An object of the present invention is to provide a caisson shear key structure and a construction method thereof, which can effectively reduce the blind area of ​​the caisson, improve the efficiency and safety of underwater earthwork, and at the same time, do not affect its use as a force transmission structure after the bottom is sealed.

[0004] In order to achieve these purposes and other advantages according to the present invention, a caisson shear key structure is provided, including a plurality of shear key structural units, which are arranged on the inner side of the first section steel shell caisson, and the plurality of shear key structural units are overlapped with each other to form a caisson shear key structure, wherein the shear key structural units include an inclined steel plate, a vertical steel plate and a "'"-shaped steel shell plate, and the inner side of the first section steel shell caisson is recessed inward to form a step-shaped notch which is small at the top and large at the bottom, and the outer side surface thereof is flush with the inner side surface of the first section steel shell caisson, and the "'"-shaped steel shell plate is fixed to the top and upper part of the step-shaped notch, and the inclined steel plate is connected to the inner side and the vertical steel plate of the first section steel shell caisson by a rotating shaft Rotationally connected, the lower end of the inclined steel plate is located at the lower end surface of the step-shaped notch, the upper end of the vertical steel plate is connected to the lower end of the "'"-shaped steel shell plate by a soft structure, the inclined steel plate and the vertical steel plate are driven to open or close by a driving mechanism, and the inclined steel plate and the vertical steel plate are completely retracted into the step-shaped notch when they are closed, and when the inclined steel plate and the vertical steel plate are opened, the inclined steel plate is in an inclined state, the vertical steel plate is just in a vertical state and the top surface is flush with the step surface of the step-shaped notch, and in the open state, adjacent shear key structural units are just overlapped to form a sealed cavity between the shear key structural unit and the step-shaped notch.

[0005] Preferably, the soft structure is nylon cloth.

[0006] Preferably, the soft structures between adjacent shear key structural units are connected as one.

[0007] Preferably, the inclined steel plates or the vertical steel plates between adjacent shear key structural units are tightly spliced ​​into one.

[0008] Preferably, the driving mechanism includes a vertical pushing rod, an upper transmission rod and a lower transmission rod. A vertical circular tube is provided inside the first section of the steel shell caisson, and its lower end is arranged flush with the lower end of the step-type notch. A vertical pushing rod is provided inside the vertical circular tube. The upper end of the vertical pushing rod protrudes out of the steel shell caisson, and the lower end is located in the plane of the step-type notch. The vertical pushing rod and the inclined steel plate are rotationally connected by the transmission rod rotating shaft through the lower transmission rod, and the vertical pushing rod and the vertical steel plate are rotationally connected by the upper transmission rod through the transmission rod rotating shaft. When the shear key structural unit is opened, the upper transmission rod is rotated to be horizontal. When the steel shell caisson is raised, the vertical circular tube and the vertical pushing rod are synchronously raised.

[0009] Preferably, the vertical circular tube is arranged close to the inner side of the first section steel shell caisson.

[0010] The present invention also provides a construction method of a caisson shear key structure, which specifically comprises the following steps:

[0011] 1) When the first section of the steel shell caisson sinks, the vertical push rod is in the upward state, and the shear key vertical steel plate, the shear key inclined steel plate and the caisson steel shell panel are on the same vertical plane, so that the shear key vertical steel plate, the shear key inclined steel plate and the nylon cloth are in a "retracted" state during the entire soil excavation and sinking process;

[0012] 2) When the caisson is raised, the vertical circular tubes and vertical push rods are extended section by section to the top surface of the caisson according to the needs of raising the caisson section by section;

[0013] 3) Before the caisson sinks into place and the bottom concrete is poured, push the vertical push rod to move it up and down, and the shear key vertical steel plate, shear key inclined steel plate and nylon cloth are fully opened through the upper transmission rod and the lower transmission rod to form the outer template structure of the shear key. The shear key structural units of the caisson overlap each other to form a whole;

[0014] 4) Self-compacting concrete is poured through vertical circular tubes to form a shear key structure.

[0015] The present invention has at least the following beneficial effects:

[0016] (1) The shear key structure of the caisson of the present invention is simple in structure and is processed and sunk together with the steel shell caisson. After the structural components are folded together during the sinking process, there is no shear key blind area, which does not affect the underwater soil excavation of the caisson. At the same time, the area of ​​the soil excavation area is increased, greatly reducing the risk of soil excavation construction in the blind area of ​​the caisson.

[0017] (2) The caisson shear key structure of the present invention adopts the form of "first folding, then opening, and then pouring", using steel plates and the like as shear key concrete pouring templates, and the shear key structure is formed after pouring concrete; the structure is simple and can be applied to various forms of compartment structures such as rectangles and arcs, and has wide applicability.

[0018] (3) The caisson shear key structure and construction method thereof of the present invention can promote the development of caisson foundation design and construction.

[0019] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the open state of the caisson shear key structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the caisson shear key structure of the present invention in a collapsed state;

[0022] Figure 3 This is a schematic diagram of the overlapping of the rectangular compartment shear key structure of the present invention;

[0023] Figure 4The present invention is a flow chart of the construction method of the caisson shear key structure.

[0024] Description of reference numerals:

[0025] 1—shear key structural unit; 2—inclined steel plate; 3—vertical steel plate; 4—connecting shaft; 5—“『”-shaped steel shell plate; 6—nylon cloth; 7—vertical circular tube; 8—vertical push rod; 9—upper transmission rod; 10—lower transmission rod; 11—transmission rod shaft. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0027] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the 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.

[0028] like Figures 1 to 3As shown, the present invention provides a caisson shear key structure, including a plurality of shear key structural units 1, which are arranged on the inner side of the first section of the steel shell caisson, and the plurality of shear key structural units 1 are overlapped with each other to form a caisson shear key structure, the shear key structural unit 1 includes an inclined steel plate 2, a vertical steel plate 3 and a "『"-shaped steel shell plate 5, the inner side of the first section of the steel shell caisson is recessed inward to form a step-shaped notch that is small on the top and large on the bottom, and its outer side surface is flush with the inner side surface of the first section of the steel shell caisson, the "『"-shaped steel shell plate 5 is fixed to the top and upper part of the step-shaped notch, the inclined steel plate 2 is rotatably connected to the inner side and vertical steel plate 3 of the first section of the steel shell caisson through a connecting shaft 4, and the inclined The lower end of the steel plate 2 is located at the lower end surface of the step-shaped notch, and the upper end of the vertical steel plate 3 is connected to the lower end of the "『"-shaped steel shell plate 5 through a soft structure. The inclined steel plate 2 and the vertical steel plate 3 are driven to open or close by a driving mechanism. When the inclined steel plate 2 and the vertical steel plate 3 are closed, they are completely retracted into the step-shaped notch. When the inclined steel plate 2 and the vertical steel plate 3 are opened, the inclined steel plate 2 is in an inclined state, and the vertical steel plate 3 is just in a vertical state and the top surface is flush with the step surface of the step-shaped notch. In the open state, the adjacent shear key structural units 1 are just overlapped so that a sealed cavity is formed between the shear key structural unit 1 and the step-shaped notch. The soft structure is nylon cloth 6. The soft structures between adjacent shear key structural units 1 are connected as a whole. The inclined steel plates 2 or vertical steel plates 3 between adjacent shear key structural units 1 are just tightly spliced ​​as a whole.

[0029] In the above technical scheme, the shear key structural unit 1 is composed as follows: a movable shear key inclined steel plate 2 and a shear key vertical steel plate 3 are arranged on the inner side of the first section steel shell caisson, and the shear key inclined steel plate 2 is connected to the caisson steel shell and the shear key vertical steel plate 3 by a connecting shaft 4, so that they can rotate around the connecting shaft 4 with each other; above the shear key vertical steel plate 3 is a "『"-shaped steel shell plate 5, and its bottom is connected to the top of the shear key vertical steel plate 3 by a nylon cloth 6, or it can be connected by other soft structures.

[0030] When the first section of the caisson is processed, the shear key vertical steel plate 3, the shear key inclined steel plate 2 and the caisson steel shell panel are on the same vertical plane and are in a retracted state. A single wall of the caisson compartment can be provided with multiple shear key structural units 1, and the specific number of settings is determined according to the size of the caisson compartment. Multiple shear key structural units 1 are combined to form a shear key structure.

[0031] When multiple shear key structural units 1 are arranged in the caisson compartment, the shear key inclined steel plates 2 between the units are overlapped with each other, the shear key vertical steel plates 3 are overlapped with each other, and are connected with nylon cloth 6. The nylon cloth 6 can be connected as a whole during processing, so that adjacent shear key structural units 1 are connected as a whole. During the process of contracting or expanding the shear key structural unit 1, water and soil will not seep into the uncast cavity inside.

[0032] In another technical solution, the driving mechanism includes a vertical push rod 8, an upper transmission rod 9 and a lower transmission rod 10. A vertical circular tube 7 is provided inside the first section of the steel shell caisson, and its lower end is arranged flush with the lower end of the step-shaped notch. A vertical push rod 8 is arranged inside the vertical circular tube 7. The upper end of the vertical push rod 8 protrudes outside the steel shell caisson, and the lower end is located in the plane of the step-shaped notch. The vertical push rod 8 is rotationally connected to the inclined steel plate 2 through the lower transmission rod 10 using the transmission rod rotating shaft 11. The vertical push rod 8 is rotationally connected to the vertical steel plate 3 through the upper transmission rod 9 using the transmission rod rotating shaft 11. When the shear key structural unit 1 is opened, the upper transmission rod 9 is in a horizontal state after rotation. When the steel shell caisson is connected, the vertical circular tube 7 and the vertical push rod 8 are synchronously connected. The vertical circular tube 7 is arranged close to the inner side of the first section of the steel shell caisson.

[0033] In the above technical solution, a vertical circular tube 7 is arranged near the inner wall of the well, and a vertical push rod 8 is arranged inside the tube, which is rotatably connected with the upper transmission rod 9 and the lower transmission rod 10 through the transmission rod rotating shaft 11. The upper transmission rod 9 and the lower transmission rod 10 are also rotatably connected with the shear key vertical surface steel plate 3 and the shear key inclined surface steel plate 2 respectively by the transmission rod rotating shaft 11. When the caisson shear key structural unit 1 is opened, the upper transmission rod 9 is horizontal after rotation, serving as the lower support of the nylon cloth 6 connecting the "『"-shaped steel shell plate 5 and the shear key vertical surface steel plate 3.

[0034] like Figure 4 As shown, the present invention also provides a construction method for a caisson shear key structure, specifically:

[0035] 1) When the first section of the steel shell caisson sinks, the vertical push rod 8 is in an upward state, and the shear key vertical steel plate 3, the shear key inclined steel plate 2 and the caisson steel shell panel are on the same vertical plane, so that the shear key vertical steel plate 3, the shear key inclined steel plate 2 and the nylon cloth 6 are in a "folded" state during the entire soil excavation and sinking process;

[0036] 2) When the caisson is raised, the vertical circular tube 7 and the vertical push rod 8 are extended section by section to the top surface of the caisson according to the need to raise the caisson section by section;

[0037] 3) Before the caisson sinks into place and the bottom concrete is poured, the vertical push rod 8 is pushed to move it up and down, and the upper transmission rod 9 and the lower transmission rod 10 are used to drive the shear key vertical steel plate 3, the shear key inclined steel plate 2 and the nylon cloth 6 to be fully opened to form the shear key outer template structure, and the caisson shear key structural units 1 are overlapped to form a whole;

[0038] 4) Self-compacting concrete is poured through the vertical circular tube 7 to form a shear key structure.

[0039] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A caisson shear key structure, characterized in that: The utility model comprises a plurality of shear key structural units, which are arranged on the inner side of the first section steel shell caisson, and the plurality of shear key structural units are overlapped with each other to form a caisson shear key structure, and the shear key structural units comprise an inclined steel plate, a vertical steel plate and a ""-shaped steel shell plate, and the inner side of the first section steel shell caisson is recessed inward to form a step-shaped notch which is small at the top and large at the bottom, and the outer side surface thereof is flush with the inner side surface of the first section steel shell caisson, and the ""-shaped steel shell plate is fixed to the top and the upper part of the step-shaped notch, and the inclined steel plate is rotatably connected to the inner side and the vertical steel plate of the first section steel shell caisson through a connecting shaft, and the lower end of the inclined steel plate is located at the The lower end surface of the step-shaped notch, the upper end of the vertical steel plate and the lower end of the "『"-shaped steel shell plate are connected by a soft structure, the inclined steel plate and the vertical steel plate are driven to open or close by a driving mechanism, and the inclined steel plate and the vertical steel plate are completely retracted into the step-shaped notch when they are closed. When the inclined steel plate and the vertical steel plate are opened, the inclined steel plate is in an inclined state, the vertical steel plate is just in a vertical state and the top surface is flush with the step surface of the step-shaped notch. In the open state, adjacent shear key structural units are just overlapped to form a sealed cavity between the shear key structural unit and the step-shaped notch.

2. The caisson shear key structure according to claim 1, characterized in that: The soft structure is nylon cloth.

3. The caisson shear key structure according to claim 1, characterized in that: The soft structures between adjacent shear key structural units are connected as a whole.

4. The caisson shear key structure according to claim 1, characterized in that: The inclined steel plates or vertical steel plates between adjacent shear key structural units are tightly spliced ​​into one.

5. The caisson shear key structure according to claim 1, characterized in that: The driving mechanism includes a vertical push rod, an upper transmission rod and a lower transmission rod. A vertical circular tube is arranged inside the first section of the steel shell caisson, and its lower end is arranged flush with the lower end of the step-type notch. A vertical push rod is arranged inside the vertical circular tube. The upper end of the vertical push rod protrudes out of the steel shell caisson, and the lower end is located in the plane of the step-type notch. The vertical push rod and the inclined steel plate are rotationally connected by the transmission rod rotating shaft through the lower transmission rod, and the vertical push rod and the vertical steel plate are rotationally connected by the transmission rod rotating shaft through the upper transmission rod. When the shear key structural unit is opened, the upper transmission rod is rotated to be horizontal. When the steel shell caisson is connected, the vertical circular tube and the vertical push rod are connected synchronously.

6. The caisson shear key structure according to claim 5, characterized in that: The vertical circular tube is arranged close to the inner side of the first section steel shell caisson.

7. The construction method of the caisson shear key structure according to claim 5, characterized in that: The specific steps include: 1) When the first section of the steel shell caisson sinks, the vertical push rod is in the upward state, and the shear key vertical steel plate, the shear key inclined steel plate and the caisson steel shell panel are on the same vertical plane, so that the shear key vertical steel plate, the shear key inclined steel plate and the soft structure are in a "folded" state during the entire soil excavation and sinking process; 2) When the caisson is raised, the vertical circular tubes and vertical push rods are extended section by section to the top surface of the caisson according to the needs of raising the caisson section by section; 3) Before the caisson sinks into place and the bottom concrete is poured, the vertical push rod is pushed to move up and down, and the shear key vertical steel plate, shear key inclined steel plate and soft structure are fully opened through the upper transmission rod and the lower transmission rod to form the outer template structure of the shear key. The shear key structural units of the caisson are overlapped to form a whole; 4) Self-compacting concrete is poured through vertical circular tubes to form a shear key structure.

Images