CN-121976551-A - Sub cofferdam construction method for construction of cross-sea tunnel

Abstract

The application discloses a sub-cofferdam construction method for constructing a cross-sea tunnel, which comprises the following steps of S1, constructing a first sub-cofferdam, reserving a first channel, constructing a first sub-cofferdam tunnel in the first sub-cofferdam, S2, dividing the first sub-cofferdam into a connecting area and a channel area through steel sheet piles after the construction of the first sub-cofferdam tunnel is finished, S3, dismantling a cofferdam structure of the channel area to form a second channel, S4, constructing a second sub-cofferdam, communicating the second sub-cofferdam with the connecting area, S5, constructing a second sub-cofferdam tunnel, communicating the second sub-cofferdam tunnel with the first sub-cofferdam tunnel, and S6, dismantling the second sub-cofferdam structure. By adopting the scheme of the application, a channel is kept between two islands all the time during construction, so that normal operation can be ensured, and meanwhile, the construction of tunnels in the first sub cofferdam and the second sub cofferdam in an open cut mode is facilitated.

Inventors

• JIANG SHAN
• ZHANG JINMING
• WAN JIANPING
• WANG QIULIN
• LIU YANPING
• HUANG YONGXI
• Dong Baohu
• LI CHEN
• YU LU
• CHANG LIQIANG
• WANG JIE
• HOU YUCHEN
• MA SHAOFENG
• GU BEIBEI
• TONG ZHONGZE
• LU WEIFEN
• QIN ZHENLONG
• WANG RUIXIANG
• WANG RUIKANG
• WU LEBIN
• LIU KUN
• PEI CHAO
• YU JIANBO
• LIU JIAWEI
• Zhu Along
• XUE YOUWEI

Assignees

• 中铁隧道局集团有限公司
• 中铁隧道集团三处有限公司

Dates

Publication Date

20260505

Application Date

20260131

Claims (10)

1. 1. The sub cofferdam construction method for constructing the cross-sea tunnel is characterized by comprising the following steps of: s1, constructing a first sub cofferdam (3), reserving a first channel (2), and constructing a first sub cofferdam (3) tunnel in the first sub cofferdam (3); S2, after the tunnel construction of the first sub cofferdam (3) is finished, the first sub cofferdam (3) is divided into a connecting area (11) and a channel area (12) through steel sheet piles (18); S3, removing a cofferdam structure of the channel region (12) to form a second channel (4); s4, constructing a second sub cofferdam (3), and enabling the second sub cofferdam (3) to be communicated with the connecting area (11); s5, constructing a second sub-cofferdam (3) tunnel, and enabling the second sub-cofferdam (3) tunnel to be communicated with the first sub-cofferdam (3) tunnel; S6, removing the structure of the second sub cofferdam (3).
2. 2. The sub-cofferdam construction method for constructing a cross-sea tunnel as set forth in claim 1, wherein the step S1 further comprises the steps of: S11, after the first sub cofferdam (3) is pumped, excavating a foundation pit, and then constructing a first occluding pile (13) at the bottom of the tunnel structure; s12, sequentially constructing a tunnel cushion layer, a bottom plate, a wall and a top plate (14); S13, constructing a reinforced concrete wall (15), a second secant pile (16), a wall body and a tunnel side wall, binding wall body steel bars, installing templates and pouring concrete to form the reinforced concrete wall (15); S14, backfilling and compacting the layers until the layers are level with the top of the tunnel; s15, constructing second occluding piles (16) on two sides of the concrete wall, wherein the pile length is 16.7m; s16, constructing a reinforced concrete beam (17) on the top of the second occluding pile (16), the reinforced concrete wall (15) and the main structure of the tunnel, and reserving a groove (171) on the top of the reinforced concrete beam (17); S17, carrying out layered backfill compaction to-8.3 m.
3. 3. The sub-cofferdam construction method for constructing a cross-sea tunnel according to claim 2, wherein the reinforced concrete wall (15) construction in step S13 comprises the steps of: S131, pile head breaking, namely breaking the pile head of the first occluding pile (13) to the elevation of the designed wall or beam bottom, exposing anchored steel bars, and enabling the length of the steel bars to be not less than 60d; s132, installing water stop bars, namely installing the water stop bars at the bottoms of the walls and the beams and the junction of the steel pipe piles, and fixing the water stop bars at intervals by adopting cement nails or other measures to prevent dislocation; S133, binding the steel bars, namely performing steel bar installation construction according to a design drawing, and erecting a personnel operation scaffold to perform auxiliary operation; S134, installing templates, namely installing template brackets on two sides of the wall and the beam, and reinforcing by adopting a counter-pulling screw rod and an inclined throwing support; S135, pouring concrete, namely adopting one-time pouring molding, adopting a day pump to pump the concrete and pouring the concrete in layers; s136, performing waterproof construction, namely sequentially installing geotextiles at the joint of the water facing side and the steel pipe pile.
4. 4.A sub-cofferdam construction method for constructing a cross-sea tunnel as set forth in claim 3, wherein said second snap-in piles (16) are constructed, said second snap-in piles (16) wrap up the reinforced concrete wall (15) and grouting reinforcement is performed between said second snap-in piles (16) and the reinforced concrete wall (15).
5. 5. The sub-cofferdam construction method for constructing a cross-sea tunnel as set forth in claim 4, wherein the step S6 further comprises the steps of: s21, inserting the steel sheet piles (18) into grooves (171) at the tops of the reinforced concrete beams (17), grouting the grooves (171), and constructing a steel structure supporting system above the tunnel; S22, backfilling and compacting the layers to +0.4m.
6. 6. The sub cofferdam construction method for constructing a cross-sea tunnel according to claim 5, wherein in the step S21, the steel structure supporting system comprises a steel enclosing purlin and a steel support (19), the steel enclosing purlin is connected with a steel sheet pile (18), the steel support (19) is connected with the steel enclosing purlin, a back support seat (191) is arranged on a tunnel roof (14), one end, far away from the steel enclosing purlin, of the steel support (19) is connected with the back support seat (191), and the back support seat (191) is arranged above a tunnel side wall.
7. 7. The sub-cofferdam construction method for constructing a cross-sea tunnel according to claim 6, wherein in step S22, sand bags are hoisted by crawler crane to backfill the upper part of the tunnel so as to avoid interference with a steel structure supporting system, and dumper sand transportation is adopted to backfill the two sides of the steel structure supporting system.
8. 8. The sub-cofferdam construction method for constructing a cross-sea tunnel according to claim 4, wherein the first occluding pile (13) at the bottom of the tunnel is a plain pile, the second occluding pile (16) is a meat pile, the first occluding pile (13) at the bottom of the tunnel is firstly constructed during construction, and the second occluding pile (16) or the second occluding pile (16) is constructed after the construction of the reinforced concrete wall (15) or the backfilling is completed.
9. 9. The sub-cofferdam construction method for constructing a cross-sea tunnel according to claim 4, wherein a pile head is reserved at the top of the second occluding pile (16), and a connector is reserved on the pile head and is connected with the steel bars of the reinforced concrete beam (17) through the connector.
10. 10. The method for constructing sub-cofferdam for constructing a cross-sea tunnel as claimed in claim 7, wherein the second engagement piles (16) are constructed by adopting a mode of staggered arrangement of meat piles and vegetable piles.

Description

Sub cofferdam construction method for construction of cross-sea tunnel Technical Field The application relates to the technical field of cross-sea tunnel construction, in particular to a sub cofferdam construction method for cross-sea tunnel construction. Background When a cross-sea tunnel is constructed between two adjacent islands, a shield or caisson mode is generally adopted for carrying out. However, the method is limited by equipment and the influence of one channel needs to be kept between two islands, so that the two modes are difficult to realize, and a new construction mode of the cross-sea tunnel is needed. Disclosure of Invention The application aims to provide a sub cofferdam construction method for constructing a cross-sea tunnel, which aims to solve the problem of how to construct the cross-sea tunnel under the condition of limited equipment and sea surface conditions. The application provides a sub cofferdam construction method for constructing a cross-sea tunnel, which adopts the following technical scheme: a sub cofferdam construction method for constructing a cross-sea tunnel comprises the following steps: s1, constructing a first sub-cofferdam, reserving a first channel, and constructing a first sub-cofferdam tunnel in the first sub-cofferdam; s2, after the construction of the first sub cofferdam tunnel is finished, dividing the first sub cofferdam into a connection area and a channel area through steel sheet piles; S3, removing a cofferdam structure of the channel area to form a second channel; S4, constructing a second sub cofferdam, and enabling the second sub cofferdam to be communicated with the connecting area; S5, constructing a second sub-cofferdam tunnel, and enabling the second sub-cofferdam tunnel to be communicated with the first sub-cofferdam tunnel; S6, removing the second sub cofferdam structure. Through adopting above-mentioned technical scheme, through the mode of constructing first sub cofferdam before constructing the second sub cofferdam earlier, guarantee to remain a channel all the time between two islands of sea can normal operating, and the setting of first sub cofferdam and second sub cofferdam can be convenient for pass through the construction tunnel of open cut mode in first sub cofferdam and the second sub cofferdam, and separate first sub cofferdam through the sheet pile then can protect the tip of tunnel through connecting region, continue to construct the tunnel after the shaping of second sub cofferdam of being convenient for, and then realize the construction of striding sea tunnel under the limited circumstances of equipment and sea condition. Optionally, step S1 further includes the following steps: s11, after the first sub cofferdam is pumped, excavating a foundation pit, and then constructing a first occluding pile at the bottom of the tunnel structure; S12, sequentially constructing a tunnel cushion layer, a bottom plate, a wall and a top plate; s13, constructing a reinforced concrete wall, waterproofing a second occluding pile, a wall body and a tunnel side wall, binding wall body steel bars, installing a template and pouring concrete to form the reinforced concrete wall; S14, backfilling and compacting the layers until the layers are level with the top of the tunnel; s15, constructing second occluding piles on two sides of the concrete wall, wherein the pile length is 16.7m; s16, constructing a reinforced concrete beam at the top of the second occluding pile, the reinforced concrete wall and the main body structure of the tunnel, and reserving a groove at the top of the reinforced concrete beam; S17, carrying out layered backfill compaction to-8.3 m. According to the technical scheme, after the foundation pit is excavated, the first occluding pile is firstly constructed so as to provide a stable foundation for tunnel construction, then after the tunnel construction, the reinforced concrete wall is firstly constructed, and then the second occluding piles on two sides of the reinforced concrete wall are constructed, so that the length of the reinforced concrete wall can be reduced, part of the reinforced concrete wall is replaced by the second occluding piles, the construction efficiency is improved, the tunnel can be constructed after the first occluding pile and the second occluding pile are firstly constructed in the traditional construction mode, but the working area for the construction of the second occluding pile is insufficient due to the fact that the space in the cofferdam is firstly formed, the first occluding pile and the tunnel are firstly constructed, then the concrete wall is constructed, and finally the second occluding pile is constructed. Optionally, the reinforced concrete wall construction in step S13 includes the following steps: S131, pile head breaking, namely breaking the pile head of the first occluding pile to the elevation of the designed wall or beam bottom, exposing anchored steel bars, and enabling the length of the ste