Construction method for temporarily locking immersed tube joint by using shear key

Abstract

The invention discloses a construction method for temporarily locking an immersed tube joint by using shear keys, which comprises the following steps of: arranging a plurality of shear keys which are vertically distributed at the side wall position and the middle partition wall position of the end surface of the immersed tube joint, and arranging a plurality of shear keys which are transversely distributed at the bottom wall position of the end surface of the immersed tube joint; then the immersed tube sections are immersed to the preset position of the seabed, then the adjacent immersed tube sections are spliced, and the shear keys on the end faces of the two adjacent immersed tube sections are distributed in a staggered mode at intervals; a constant-resistance device is installed in a gap between every two adjacent shear keys, each constant-resistance device comprises a steel sleeve and a steel strand, the steel sleeves are fixed to one shear key, the fixed ends of the steel strands are fixed to the other shear key, and the movable ends of the steel strands slide in the steel sleeves; when relative displacement occurs between the adjacent shear keys, anti-sliding resistance is generated between the steel strand and the steel sleeve, and the overall bearing effect of the shear keys is improved under the condition that the material cost is not increased.

Description

Technical Field

[0001] The present application relates to the field of immersed tube construction, and in particular to a construction method for temporarily locking immersed tube sections using shear keys. Background Art

[0002] An immersed tube tunnel is an underwater passage for vehicles built in underwater strata across rivers, bays, and straits. Its construction method involves pre-digging trenches in the underwater strata where the tunnel is to be built, floating several sections of reinforced concrete pipe segments prefabricated on a dry dock to the designated waters, and sinking the pipe segments to the designed positions in the dredged foundation trench, connecting and fixing them to form a tunnel or large underwater space. In the construction process of immersed tube tunnels, the connection of pipe segments is a crucial link. Since the pipe segments need to be docked underwater and need to withstand various complex hydrological, geological and load conditions, it is necessary to ensure that the connection between the pipe segments is both stable and reliable. The shear key, as an important load-bearing component in the pipe segment connection, plays a key role in the temporary locking and final fixation of the pipe segments.

[0003] In the related art, shear keys mainly bear the shear force caused by factors such as earthquakes and uneven settlement of pipe sections. According to the different directions of force, shear keys can be divided into horizontal shear keys and vertical shear keys. Horizontal shear keys mainly bear the horizontal shear force caused by earthquakes, while vertical shear keys mainly bear the vertical shear force caused by uneven settlement of pipe sections and earthquakes.

[0004] Regarding the above-mentioned related technologies, there are the following defects: when the immersed tube segment sinks, only the interaction force is generated between the two adjacent shear keys. When the shear force borne by the shear key is too large, it is easy to deform or break. If the shear key's bearing capacity is increased by increasing its cross-sectional area, the material cost will increase, so there is still room for improvement. Summary of the invention

[0005] In order to improve the overall bearing effect of the shear key without increasing the material cost, the present application provides a construction method for temporarily locking the immersed tube section by using the shear key.

[0006] The present application provides a construction method for temporarily locking an immersed tube segment using a shear key, which adopts the following technical solution: A construction method for temporarily locking an immersed tube segment using a shear key comprises the following steps: S1: Prefabricated immersed tube segment, with a number of vertically distributed shear keys arranged at the side wall position and the middle partition wall position of the end face of the immersed tube segment, and a number of horizontally distributed shear keys arranged at the bottom wall position of the end face of the immersed tube segment; S2: sinking and connecting the immersed tube segments. After sinking the immersed tube segments to the predetermined position on the seabed, adjacent immersed tube segments are spliced. Several shear keys at the end faces of two adjacent immersed tube segments are staggered and space is left between adjacent shear keys. S3: A constant resistance device is installed in the gap between adjacent shear keys, the constant resistance device includes a steel sleeve and a steel strand. In adjacent shear keys, the steel sleeve is fixed at one of the shear keys, the fixed end of the steel strand is fixed at the other shear key, and the movable end of the steel strand slides in the steel sleeve; when relative displacement occurs between adjacent shear keys, anti-slip resistance is generated between the steel strand and the steel sleeve.

[0007] By adopting the above technical scheme, through prefabricating immersed tube sections, a plurality of shear keys are vertically distributed at the side wall position and the middle partition wall position of the end face of the immersed tube section, and horizontally distributed at the bottom wall position of the end face of the immersed tube section. When two immersed tube sections are spliced, the plurality of shear keys at the end faces of two adjacent immersed tube sections are staggered and distributed, and a gap is reserved for accommodating the constant resistance device. The constant resistance device is installed after the adjacent immersed tube sections are assembled. The constant resistance device is mainly composed of a steel sleeve and a steel strand. When the immersed tube section sinks, the steel strand slides in the steel sleeve and generates anti-slip resistance. The downwardly moving shear key transmits the force to the upper and lower shear keys respectively through the upper and lower constant resistance devices, so that multiple shear keys bear the force together, which is beneficial to improving the overall load-bearing effect of the shear keys without increasing material costs.

[0008] Preferably, in S1, the shear key at the middle partition wall is a concrete structure, and the plurality of shear keys at the middle partition wall are distributed in two rows. A plurality of nose support bridges are arranged at the middle partition wall of the immersed tube section, and the plurality of nose support bridges correspond to the plurality of shear keys one by one, and the shear keys and the corresponding nose support bridges are integrally cast. By adopting the above technical scheme, the nose support beam and the shear key work together during the temporary locking process of the immersed tube segment. The nose support beam can share part of the load acting on the immersed tube segment, including its own weight, water flow force, buoyancy and the force generated by construction machinery, which helps to reduce the stress on key connecting components such as the shear key and prevent damage or failure due to excessive force. In addition, the setting of the nose support beam can also provide construction personnel with certain auxiliary positioning and adjustment functions. During the pipe segment docking process, construction personnel can use the nose support beam to fine-tune the position and posture of the pipe segment to ensure the accuracy and precision of the docking, which helps to improve construction efficiency and quality.

[0009] Preferably, in S1, the shear key at the side wall position of the end face of the immersed tube segment is a steel structure, and according to the installation position of the shear key, horizontal steel bars are welded at the side wall steel bars of the immersed tube segment to determine the installation plane of the shear key, and then the embedded parts of the shear key are hoisted to the installation plane and fixed with initial positioning steel bars.

[0010] By adopting the above technical solution, the shear keys of the steel structure are used as temporary support points at the side walls of the immersed tube segments, thereby improving the structural strength of the shear keys, which is beneficial to improving the stability of the periphery of the immersed tube tunnel.

[0011] Preferably, after the embedded parts of the shear keys at the side wall positions of the immersed tube segments in S1 are installed in place, the positions of the embedded parts are detected, then the end mold of the immersed tube segment is installed, and the positions of the embedded parts are detected again, and according to the re-measurement results of the positions of the embedded parts, part of the initial positioning steel bars of the embedded parts are removed, and then the installation position of the embedded parts is readjusted, and the left and right and inclination angles are adjusted by using a small jack, and finally the embedded parts are fixed with precision positioning steel bars, and the embedded parts are connected to the end mold of the immersed tube segment with fixing bolts so that the surface of the end mold is close to the surface of the embedded parts.

[0012] By adopting the above technical scheme, the position of the embedded parts is detected before and after the installation of the end mold, and the position of the embedded parts is adjusted after releasing the initial positioning steel bars. Finally, the embedded parts are completely locked with the fine positioning steel bars. At the same time, the embedded parts are connected to the end mold of the immersed tube section, so that the surface of the end mold is close to the surface of the embedded parts, and the problem of cement slurry entering the embedded sleeve of the embedded parts can be improved, which is conducive to the smooth installation of the subsequent shear keys.

[0013] Preferably, in the step of installing the shear key at the side wall of the submerged pipe segment in S1, a thick asbestos liner plate is arranged between the embedded part of the shear key and the shear key.

[0014] By adopting the above technical solution, since the embedded parts and the shear keys are both steel structures, and the asbestos liner board, as a non-metallic material, has good isolation properties, it can effectively isolate the direct metal contact between the steel shear key and the embedded parts, avoiding electrochemical corrosion or physical wear that may be caused by direct contact, which is beneficial to extending the service life of the shear key and the embedded parts.

[0015] Preferably, during the shear key installation step in S1, an embedded part of a rubber bearing is installed at one end of the shear key; and after completing the immersed tube segment assembly step in S3, the rubber bearing is installed at the shear key, and the rubber bearing is located in the gap between two adjacent shear keys.

[0016] By adopting the above technical solution, the rubber bearing can absorb and disperse the stress between the shear keys caused by the movement or deformation of the pipe section, avoiding the damage to the shear key structure caused by stress concentration. Together with the constant resistance device, it plays a buffering role, which helps to protect the integrity and stability of the shear key.

[0017] Preferably, in the nose support bridge casting construction step in S1, the embedded parts are embedded in the upper or lower part of the nose support bridge, and the installation steps of the upper guide device and the lower guide device are completed accordingly; when the immersed tube segment assembly step of S3 is performed, the two immersed tube segments slide horizontally into place under the cooperative guiding action of the upper guide device and the lower guide device.

[0018] By adopting the above technical solution, the upper guide device and the lower guide device play a guiding role, which is beneficial to improving the assembly accuracy of the two immersed tube sections.

[0019] Preferably, before performing the pouring steps of the nose support bridge and the shear key in S1, the main reinforcement of the nose support bridge and the steel bars of the rubber support embedded parts are tied together and fixed to the steel bars of the shear key; and the steel bars of the upper guide device embedded parts and the steel bars of the lower guide device embedded parts are tied and fixed to the steel bars of the nose support bridge.

[0020] By adopting the above technical scheme, the embedded parts of the nose support bridge, the rubber support and the steel bars of the shear key are tied and formed, and the embedded parts of the upper guide device, the embedded parts of the lower guide device and the nose support bridge are tied and formed, which is beneficial to improving the structural firmness of each component.

[0021] In summary, the present application includes at least one of the following beneficial technical effects: 1. A plurality of shear keys are vertically distributed at the side wall and the middle partition wall of the end face of the immersed tube segment, and horizontally distributed at the bottom wall of the end face of the immersed tube segment. When two immersed tube segments are spliced, the plurality of shear keys at the end faces of two adjacent immersed tube segments are staggered and a gap is left for accommodating the constant resistance device. When the immersed tube segment settles, the steel strand slides in the steel sleeve and generates anti-slip resistance. The shear key that moves downward transmits the force to the upper and lower shear keys through the upper and lower constant resistance devices, respectively, so that the plurality of shear keys bear the force together, which is beneficial to improving the overall load-bearing effect of the shear keys without increasing the material cost. 2. By arranging the nose support bridge between the two rows of shear keys at the middle partition wall, it is helpful to share part of the load for the shear keys, which helps to reduce the stress of key connecting parts such as shear keys and prevent damage or failure caused by excessive stress; 3. The position of the embedded parts was detected before and after the installation of the end mold, and the position of the embedded parts was adjusted by removing the initial positioning steel bars. Finally, it was completely locked with the fine positioning steel bars. At the same time, the embedded parts were connected to the end mold of the immersed tube section, so that the surface of the end mold was close to the surface of the embedded parts, and the problem of cement slurry entering the embedded sleeve of the embedded parts could be improved, which was conducive to the smooth installation of the subsequent shear keys. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a schematic diagram of one end of an immersed tube segment in a construction method for temporarily locking an immersed tube segment by using a shear key in an embodiment of the present application.

[0023] Figure 2 It is a schematic diagram of the other end of an immersed tube segment in a construction method for temporarily locking an immersed tube segment by using a shear key in an embodiment of the present application.

[0024] Figure 3 It is a connection schematic diagram of a constant resistance device after two immersed tube segments are spliced ​​together in a construction method for temporarily locking an immersed tube segment by using a shear key in an embodiment of the present application.

[0025] Figure 4 yes Figure 3 A magnified schematic diagram of center A.

[0026] Explanation of the reference numerals: 1. immersed tube section; 11. side wall; 12. bottom wall; 13. middle partition wall; 2. shear key; 3. rubber support; 4. nose support beam; 5. constant resistance device; 51. steel sleeve; 52. steel strand; 6. upper guide device; 7. lower guide device. DETAILED DESCRIPTION

[0027] The following is combined with Figure 1-4 This application is described in further detail.

[0028] The present application embodiment discloses a construction method for temporarily locking an immersed tube segment 1 by using a shear key 2, referring to Figures 1 to 3 , including the following steps: S1: A prefabricated immersed tube segment 1, wherein a plurality of vertically distributed shear keys 2 are arranged at the side wall 11 and the middle partition wall 13 of the end face of the immersed tube segment 1, and a plurality of transversely distributed shear keys 2 are arranged at the bottom wall 12 of the end face of the immersed tube segment 1.

[0029] Specifically, firstly, the overall reinforcement of the immersed tube segment 1 is tied in the construction site workshop, including the bottom wall 12 , the side wall 11 , the middle partition wall 13 and the top wall of the immersed tube segment 1 .

[0030] In this embodiment, the shear key 2 at the side wall 11 on the end face of the immersed tube segment 1 is a steel structure. When the horizontal main reinforcement of the side wall 11 of the immersed tube segment 1 is tied to the height position of the top of the shear key 2, the binding of the wall butt reinforcement (hooks, reinforcement) at the embedded part installation location is suspended first, and preparation is made for the installation of the shear key 2 embedded part.

[0031] According to the installation position of the shear key 2 and the inclination angle requirements for the installation of the embedded parts, horizontal steel bars are welded at the side wall 11 steel bars at the end face of the immersed tube segment 1 to determine the installation plane of the shear key 2 embedded parts, and then the embedded parts of the shear key 2 are hoisted to the installation plane, and after completing the preliminary measurement and positioning, they are fixed with the initial positioning steel bars.

[0032] In this embodiment, the shear keys 2 at the middle partition wall 13 at the end face of the immersed tube segment 1 and at the bottom wall 12 are both concrete structures. The multiple shear keys 2 located at the middle partition wall 13 are distributed in two rows. A multiple nose support bridges 4 are arranged at the middle partition wall 13 of the immersed tube segment 1. The multiple nose support bridges 4 correspond one-to-one to the multiple shear keys 2. The shear keys 2 and the corresponding nose support bridges 4 are integrally cast and a nose support bridge 4 is arranged between the two rows of shear keys 2, wherein two shear keys 2 at the same height in the two rows of shear keys 2 correspond to one nose support bridge 4.

[0033] Reference Figure 3 and Figure 4 In this embodiment, one end of the shear key 2 is installed with an embedded part of a rubber support 3; so that after the subsequent sinking and assembling steps of the immersed tube segment 1 are completed, the rubber support 3 is installed in the gap between two adjacent shear keys 2. In addition, an embedded part of an upper guide device 6 is installed on the upper part of the nose support bridge 4, and an embedded part of a lower guide device 7 is installed on the lower part of the nose support bridge 4, which are used to complete the corresponding installation steps of the upper guide device 6 and the lower guide device 7, so that in the subsequent assembling steps of the immersed tube segment 1, the cooperation and guiding effect between the two immersed tube segments 1 between the upper guide device 6 and the lower guide device 7 is utilized to complete the purpose of horizontal sliding of the immersed tube segment 1. Among them, the upper guide device 6 and the lower guide device 7 both adopt a triangular structure guide frame, which improves stability and facilitates mutual cooperation.

[0034] Before the pouring construction of the nose support bridge 4 and the shear key 2, the main reinforcement of the nose support bridge 4 and the steel bars of the embedded parts of the rubber support 3 are tied and fixed to the steel bars of the shear key 2. In addition, before the pouring construction step of the nose support bridge 4, the embedded parts are embedded in the upper or lower part of the nose support bridge 4, and then the end mold installation step of the immersed tube segment 1 is carried out.

[0035] Specifically, a support is first built on the end face of the immersed tube segment 1, and a socket-type disc-type support system is used to facilitate personnel operation and provide support for the end mold. When installing the end mold of the immersed tube segment 1, the position of the embedded parts is detected again. According to the re-test results of the embedded parts position, some of the initial positioning steel bars of the embedded parts are removed, and then the installation position of the embedded parts is readjusted, and the left and right and inclination angles are adjusted by a small jack. Finally, the embedded parts are fixed with precision positioning steel bars, and the embedded parts are connected to the end mold of the immersed tube segment 1 with fixing bolts, so that the surface of the end mold is close to the surface of the embedded parts. In addition, the side mold, inner mold and top mold of the immersed tube segment 1 are built. In addition, it is necessary to set up another template for the shear key 2 at the position of the nose support bridge 4 and the middle partition wall 13, and finally the immersed tube segment 1, the shear key 2 and the corresponding nose support bridge 4 are integrally cast.

[0036] After removing the template of the immersed tube segment 1, the shear key 2 at the side wall 11 is installed. During the installation, a thick asbestos liner board needs to be set between the embedded parts of the shear key 2 and the shear key 2. As a non-metallic material, the asbestos liner board has good isolation properties and can effectively isolate the direct metal contact between the steel shear key 2 and the embedded parts, avoiding electrochemical corrosion or physical wear that may be caused by direct contact, which is beneficial to extending the service life of the shear key 2 and the embedded parts.

[0037] S2: sinking and connecting the immersed tube segments 1, after sinking the immersed tube segments 1 to the predetermined position on the seabed, the adjacent immersed tube segments 1 are spliced. When the immersed tube segments 1 are assembled, the two immersed tube segments 1 slide horizontally into place under the cooperation and guidance of the upper guide device 6 and the lower guide device 7.

[0038] After the immersed tube segment 1 is completely in place, the plurality of shear keys 2 at the end surfaces of two adjacent immersed tube segments 1 are staggered and distributed, and gaps are left between adjacent shear keys 2 .

[0039] S3: Then, the rubber bearing 3 is installed at the shear key 2, and the rubber bearing 3 is located in the gap between two adjacent shear keys 2. In addition, a constant resistance device 5 is installed in the gap between adjacent shear keys 2, and the constant resistance device 5 and the rubber bearing 3 are staggered at the gap. The constant resistance device 5 includes a steel sleeve 51 and a steel strand 52. In the adjacent shear keys 2, the steel sleeve 51 is pre-embedded and fixed in the upper shear key 2 in advance in step S1, and the movable end of the steel strand slides in the steel sleeve 51. Then in step S3, the fixed end of the steel strand 52 is locked in the lower shear key 2 by a locking piece, so that when there is a relative displacement between the adjacent shear keys 2, an anti-slip resistance is generated between the steel strand 52 and the steel sleeve 51. The shear key 2 that moves downward transmits the force to the upper and lower shear keys 2 through the upper and lower constant resistance devices 5 respectively, so that multiple shear keys 2 bear the force together, which is conducive to improving the overall load-bearing effect of the shear key 2 without increasing the material cost.

[0040] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A construction method for temporarily locking an immersed tube segment using a shear key, characterized in that: The following steps are involved: S1: a prefabricated immersed tube segment (1), a plurality of vertically distributed shear keys (2) are arranged at the side wall (11) and the middle partition wall (13) of the end surface of the immersed tube segment (1), and a plurality of transversely distributed shear keys (2) are arranged at the bottom wall (12) of the end surface of the immersed tube segment (1); S2: sinking and connecting the immersed tube segments (1), after sinking the immersed tube segments (1) to a predetermined position on the seabed, adjacent immersed tube segments (1) are spliced, and a plurality of shear keys (2) at the end surfaces of two adjacent immersed tube segments (1) are arranged at staggered intervals, and gaps are left between adjacent shear keys (2); S3: A constant resistance device (5) is installed in the gap between adjacent shear keys (2), the constant resistance device (5) comprising a steel sleeve (51) and a steel strand (52), in the adjacent shear keys (2), the steel sleeve (51) is fixed at one of the shear keys (2), the fixed end of the steel strand (52) is fixed at the other shear key (2), and the movable end of the steel strand slides in the steel sleeve (51); when relative displacement occurs between adjacent shear keys (2), anti-slip resistance is generated between the steel strand (52) and the steel sleeve (51).

2. A construction method for temporarily locking an immersed tube segment (1) using a shear key (2) according to claim 1, characterized in that: In the S1, the shear key (2) at the position of the middle partition wall (13) is a concrete structure, and a plurality of shear keys (2) at the position of the middle partition wall (13) are distributed in two rows. A plurality of nose support bridges (4) are arranged at the position of the middle partition wall (13) of the immersed tube section (1), and the plurality of nose support bridges (4) correspond to the plurality of shear keys (2) one by one. The shear keys (2) and the corresponding nose support bridges (4) are integrally cast and formed.

3. A construction method for temporarily locking an immersed tube segment (1) using a shear key (2) according to claim 1, characterized in that: In the above S1, the shear key (2) at the side wall (11) of the end face of the immersed tube segment (1) is a steel structure. According to the installation position of the shear key (2), horizontal steel bars are welded at the steel bars of the side wall (11) of the immersed tube segment (1) to determine the installation plane of the shear key (2). Then, the embedded parts of the shear key (2) are hoisted to the installation plane and fixed with initial positioning steel bars.

4. A construction method for temporarily locking an immersed tube segment (1) using a shear key (2) according to claim 3, characterized in that: After the embedded parts of the shear key (2) at the side wall (11) of the immersed tube segment (1) in S1 are installed in place, the position of the embedded parts is detected, then the end mold of the immersed tube segment (1) is installed, and the position of the embedded parts is detected again. According to the re-test result of the position of the embedded parts, part of the initial positioning steel bars of the embedded parts are removed, and then the installation position of the embedded parts is readjusted, and the left and right and inclination angles are adjusted by using a small jack. Finally, the embedded parts are fixed with precision positioning steel bars, and the embedded parts are connected to the end mold of the immersed tube segment (1) with fixing bolts so that the surface of the end mold is in close contact with the surface of the embedded parts.

5. A construction method for temporarily locking an immersed tube segment (1) using a shear key (2) according to claim 3, characterized in that: During the step of installing the shear key (2) at the side wall (11) of the submerged pipe section (1) in S1, a thick asbestos liner plate is arranged between the embedded part of the shear key (2) and the shear key (2).

6. A construction method for temporarily locking an immersed tube segment (1) using a shear key (2) according to claim 2, characterized in that: During the step of installing the shear key (2) in S1, an embedded part of a rubber support (3) is installed at one end of the shear key (2); and after completing the step of assembling the immersed tube segment (1) in S3, the rubber support (3) is installed at the shear key (2), and the rubber support (3) is located in the gap between two adjacent shear keys (2).

7. A construction method for temporarily locking an immersed tube segment (1) using a shear key (2) according to claim 6, characterized in that: During the pouring construction step of the nose support bridge (4) in S1, the embedded parts are embedded in the upper or lower part of the nose support bridge (4), and the installation steps of the upper guide device (6) and the lower guide device (7) are completed accordingly; during the assembling step of the immersed tube segment (1) in S3, the two immersed tube segments (1) slide horizontally into place under the cooperative guiding action between the upper guide device (6) and the lower guide device (7).

8. A construction method for temporarily locking an immersed tube segment (1) using a shear key (2) according to claim 7, characterized in that: Before the step of casting the nose support bridge (4) and the shear key (2) in S1, the main reinforcement of the nose support bridge (4) and the steel bars of the embedded parts of the rubber support (3) are tied and fixed to the steel bars of the shear key (2); and the steel bars of the embedded parts of the upper guide device (6) and the steel bars of the embedded parts of the lower guide device (7) are tied and fixed to the steel bars of the nose support bridge (4).

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