High-pressure water tunnel structure crossing a seismogenic fault

Abstract

The application discloses a high-pressure water conveying tunnel structure, in particular to a high-pressure water conveying tunnel structure crossing a seismogenic fault, and belongs to the technical field of water conservancy and hydropower engineering structure design and construction. The application provides a high-pressure water conveying tunnel structure crossing a seismogenic fault, which can maintain a sufficient water conveying section when a fault occurs with a large dislocation. The high-pressure water conveying tunnel structure comprises a high-pressure water conveying tunnel body crossing a seismogenic fault, and further comprises a preset fault dislocation joint structure, wherein the high-pressure water conveying tunnel body crosses the seismogenic fault through the preset fault dislocation joint structure; after an earthquake dislocation, the high-pressure water conveying tunnel body located in the seismogenic fault maintains a water conveying area of a water conveying section under the cooperation of the preset fault dislocation joint structure.

Description

High-pressure water conveyance tunnel structure traversing the seismogenic fault Technical Field

[0001] This invention relates to a high-pressure water conveyance tunnel structure, and more particularly to a high-pressure water conveyance tunnel structure that crosses a seismic fault, belonging to the technical field of hydraulic and hydropower engineering structure design and construction. Background Technology

[0002] Earthquakes that trigger faults involve large displacements and occur suddenly. The lining structure of water conveyance tunnels cannot withstand the enormous energy of fault displacement. Therefore, when a high-pressure water conveyance tunnel is broken by a fault, insufficient water passage, collapse, or other reasons can prevent water from being discharged from the tunnel, leading to excessively high internal water pressure. This can then trigger further collapses, landslides, and other secondary disasters.

[0003] If methods such as widening the excavation are used to ensure sufficient water passage cross-section after the tunnel is misaligned, the excessively large clearance cross-section will have a significant impact on stability during the construction and operation periods, which is detrimental to safety. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-pressure water conveyance tunnel structure that can maintain a sufficient water-carrying cross-section when a large displacement occurs in the fault.

[0005] The technical solution adopted to solve the above-mentioned technical problems is: a high-pressure water conveyance tunnel structure that traverses an earthquake-inducing fault, including a high-pressure water conveyance tunnel body that traverses the earthquake-inducing fault, and the high-pressure water conveyance tunnel structure also includes a pre-set fault staggered structure, through which the high-pressure water conveyance tunnel body traverses the earthquake-inducing fault; after an earthquake, the high-pressure water conveyance tunnel body located within the earthquake-inducing fault maintains the water conveyance area of ​​the water conveyance section with the cooperation of the pre-set fault staggered structure.

[0006] Furthermore, the high-pressure water conveyance tunnel structure also includes a pre-set structural joint, with a pre-set fault staggered structure passing through the pre-set structural joint set along the seismic fault.

[0007] The preferred method of the above scheme is to install anti-seepage and water-stopping components in the pre-set structural joints.

[0008] Furthermore, the pre-designed fault staggered structure includes a tunnel widening section and a bifurcated connecting branch tunnel system. The high-pressure water conveyance tunnel bodies located at both ends of the tunnel widening section are connected separately along the water conveyance direction through the bifurcated connecting branch tunnel system, and the pre-designed structural joint intersects the axis of the tunnel widening section at an inclination.

[0009] The preferred embodiment of the above scheme is that the bifurcated connecting branch tunnel system includes at least four connecting bifurcated branch tunnels arranged in parallel along the water conveyance direction, and the high-pressure water conveyance tunnel bodies located at both ends of the tunnel widening section are connected separately along the water conveyance direction through each connecting bifurcated branch tunnel.

[0010] Furthermore, each connecting branch tunnel includes at least one main connecting branch tunnel located at the bottom of the tunnel widening section.

[0011] The preferred embodiment of the above scheme is that each connecting branch tunnel is separated by concrete partition walls extending along the water conveyance direction.

[0012] Furthermore, there are six connecting branch tunnels arranged in parallel along the water conveyance direction. The projection of the tunnel widening section in its cross-section is an ellipse with its major axis arranged horizontally. The six connecting branch tunnels are arranged in two layers along the water conveyance direction within the tunnel widening section, with the two connecting branch tunnels in the middle being the main connecting branch tunnels.

[0013] The preferred embodiment of the above scheme is that six connecting branch tunnels are arranged in parallel along the water conveyance direction. The projection of the tunnel widening section in its cross-section is an ellipse with its major axis arranged vertically. The six connecting branch tunnels are arranged in two rows on the left and right sides along the water conveyance direction in the tunnel widening section. The two connecting branch tunnels in the middle are the main connecting branch tunnels.

[0014] Furthermore, the projection of the tunnel widening section within its cross-section is a gate-shaped structure with a circular arc at the top. There are four connecting branch tunnels arranged in parallel along the water conveyance direction, with the center points of the four connecting branch tunnels forming a regular quadrilateral extending along the water conveyance direction within the tunnel widening section.

[0015] The beneficial effects of this invention are as follows: The technical solution provided in this application is based on the existing high-pressure water conveyance tunnel body that traverses an earthquake-inducing fault. By adding a pre-set fault misalignment structure, the high-pressure water conveyance tunnel body traverses the earthquake-inducing fault, thus allowing the high-pressure water conveyance tunnel body to pass through the fault via the pre-set fault misalignment structure. In this way, after an earthquake occurs, the high-pressure water conveyance tunnel body located within the earthquake-inducing fault maintains the water conveyance area of ​​the cross-section with the cooperation of the pre-set fault misalignment structure. This achieves the goal of this application, enabling the water conveyance tunnel to maintain a sufficient water-carrying cross-section even when a large fault displacement occurs, adapting to different fault displacement mechanisms, preventing tunnel collapse, and ensuring tunnel stability during construction and operation. Attached Figure Description

[0016] Figure 1 is a schematic diagram of the high-pressure water conveyance tunnel structure of the present invention passing through the fault fault;

[0017] Figure 2 is a schematic diagram of the high-pressure water conveyance tunnel structure of the present invention that undergoes displacement when passing through the fault fault.

[0018] Figure 3 is a cross-sectional view AA of Figure 2;

[0019] Figures 4 and 5 are schematic diagrams showing different directions of displacement;

[0020] Figure 6 is a cross-sectional view of a design example of the high-pressure water conveyance tunnel structure that crosses the seismic fault of the present invention.

[0021] Figure 7 is a schematic diagram of the fault that occurred in Figure 6.

[0022] The diagram is marked as follows: 1. Seismogenic fault; 2. High-pressure water conveyance tunnel body; 3. Pre-set fault staggered structure; 4. Pre-set structural joint; 5. Tunnel widening section; 6. Bifurcation connecting branch tunnel system; 7. Connecting bifurcation branch tunnel. Detailed Implementation

[0023] Figures 1 to 7 illustrate a high-pressure water conveyance tunnel structure provided by this invention, which allows the water conveyance tunnel to maintain a sufficient water-carrying cross-section even when a large fault displacement occurs. The high-pressure water conveyance tunnel structure includes a high-pressure water conveyance tunnel body 2 that traverses the seismogenic fault 1. The structure also includes a pre-set fault misalignment structure 3, through which the high-pressure water conveyance tunnel body 2 traverses the seismogenic fault 1. After an earthquake, the high-pressure water conveyance tunnel body 2, located within the seismogenic fault 1, maintains its water-carrying cross-section area with the assistance of the pre-set fault misalignment structure 3. The technical solution provided in this application is based on the existing high-pressure water conveyance tunnel body that traverses an earthquake-inducing fault. By adding a pre-set fault misalignment structure, the high-pressure water conveyance tunnel body traverses the earthquake-inducing fault through this structure. Thus, after an earthquake, the high-pressure water conveyance tunnel body located within the earthquake-inducing fault maintains its water conveyance cross-sectional area with the assistance of the pre-set fault misalignment structure. This achieves the goal of maintaining a sufficient water-carrying cross-section even when a large fault displacement occurs, adapting to different fault displacement mechanisms, preventing tunnel collapse, and ensuring tunnel stability during construction and operation.

[0024] Accordingly, to minimize leakage of high-pressure water in the water conveyance tunnel through the seismic fault, the high-pressure water conveyance tunnel structure described in this application further includes a pre-set structural joint 4, through which the pre-set fault staggered structure 3 passes. A seepage-proof and water-stopping component is then installed within the pre-set structural joint 4. More specifically, the pre-set fault staggered structure 3 includes a tunnel widening section 5 and a bifurcation connecting branch system 6. The high-pressure water conveyance tunnel bodies 2 located at both ends of the tunnel widening section 5 are connected separately along the water conveyance direction via the bifurcation connecting branch system 6. The pre-set structural joint 4 intersects the axis of the tunnel widening section at an incline. Preferably, the bifurcation connecting branch system 6 includes at least four connecting bifurcation branches 7 arranged in parallel along the water conveyance direction. The high-pressure water conveyance tunnel bodies 2 located at both ends of the tunnel widening section 5 are connected separately along the water conveyance direction through each connecting bifurcation branch 7. Each connecting bifurcation branch 7 includes at least one main connecting bifurcation branch located at the lowest point of the tunnel widening section 5. For ease of construction, each connecting branch tunnel 7 in this application is separated by concrete partition walls extending along the water conveyance direction.

[0025] Furthermore, based on the water conveyance cross-section of the water conveyance tunnel itself, this application specifies six parallel connecting branch tunnels 7 arranged along the water conveyance direction. The projection of the tunnel widening section 5 within its cross-section is an ellipse with its major axis arranged horizontally. The six connecting branch tunnels 7 are arranged in two layers extending along the water conveyance direction within the tunnel widening section 5, with the two middle connecting branch tunnels 7 being main connecting branch tunnels. Alternatively, six parallel connecting branch tunnels 7 are arranged along the water conveyance direction, with the projection of the tunnel widening section 5 within its cross-section being an ellipse with its major axis arranged vertically. The six connecting branch tunnels 7 are arranged in two rows extending along the water conveyance direction within the tunnel widening section 5, with the two middle connecting branch tunnels 7 being main connecting branch tunnels.

[0026] Of course, depending on the water conveyance section of the water conveyance tunnel itself, the projection of the tunnel widening section 5 in its cross-section can also be set as a gate-shaped structure with a circular arc at the top. There are four connecting branch tunnels 7 arranged in parallel along the water conveyance direction. The center points of the four connecting branch tunnels 7 are arranged in a regular quadrilateral extending along the water conveyance direction within the tunnel widening section 5.

[0027] In summary, the high-pressure water conveyance tunnel structure provided in this application ensures that it can still meet normal water flow requirements even in the event of sudden fault dislocation, preventing secondary disasters. The structure itself exhibits no significant stability issues during operation or construction, and its safety is further enhanced by dividing the main tunnel into multiple branch tunnels.

[0028] The technical solution of this application will be further described below through specific embodiments:

[0029] As shown in Figure 1, the section of the tunnel crossing the active fault adopts an enlarged structure. The water conveyance tunnel branches from a main tunnel into several branch tunnels, which are separated by partition walls. Structural joints are set at the location of the active fault, and waterstops are installed within the joints to ensure seepage prevention during normal operation.

[0030] After a misalignment occurs, as shown in Figures 2 and 3, by designing the size and location of each branch opening on the cross-section, it can be ensured that the cross-sectional size of the flow passage is not reduced compared to the main opening under the designed dislocation conditions. Simultaneously, the use of a distributed design with multiple branch openings, interspersed with concrete pouring, ensures the stability and safety of the entire tunnel.

[0031] To prevent soil and rock debris from entering the water conveyance tunnel after fault displacement, the sidewalls and arch can be thickened.

[0032] For faults with different slip mechanisms, the cross-sectional shape or the arrangement of the burrows can be adjusted to adapt to the fault slip direction, as shown by the arrows in Figures 4 and 5.

[0033] Example 1

[0034] As shown in Figures 6 and 7, a water conveyance tunnel with a diameter of 11.0m crosses an active fault with a maximum potential displacement of 2.5m and a dip angle of 90°. If widening the tunnel or widening it with an exposed pipe method is adopted, the widened tunnel diameter will reach 16.0m. Maintaining tunnel stability during construction and operation will be extremely difficult.

[0035] A total of 4 branch tunnels are set up, each with a diameter of 7.2m. The minimum distance between the branch tunnels, i.e. the thickness of the partition wall, is about 2m. The distance between the branch tunnel walls and the excavation outline of the expanded structure is 2.5m, which ensures that no soil or rock debris will enter the tunnel when the fault displacement is 2.5m.

[0036] Under the condition of a 2.5m strike-slip and reverse-slip fault, as shown by the arrow in Figure 7, the cross-sectional area of ​​the water passage is approximately 92m2, which is basically equal to the cross-sectional area of ​​the main tunnel, which is 94m2.

[0037] Overall, the expansion of the tunnel span by 21.54m and the excavation height by 23.5m are within the scope of existing engineering experience, and the construction is not difficult.

Claims

1. A high-pressure water conveyance tunnel structure traversing a seismogenic fault, comprising a high-pressure water conveyance tunnel body (2) traversing the seismogenic fault (1), characterized in that: The high-pressure water conveyance tunnel structure also includes a pre-set fault staggered structure (3). The high-pressure water conveyance tunnel body (2) passes through the seismic fault (1) through the pre-set fault staggered structure (3). After the earthquake, the high-pressure water conveyance tunnel body (2) located in the seismic fault (1) maintains the water conveyance area of ​​the water conveyance section with the cooperation of the pre-set fault staggered structure (3). The pre-set fault staggered structure (3) includes a tunnel widening section (5) and a bifurcation connecting branch system (6). The high-pressure water conveyance tunnel body (2) located at both ends of the tunnel widening section (5) is connected separately along the water conveyance direction through the bifurcation connecting branch system (6). The pre-set structural joint (4) intersects the axis of the tunnel widening section at an inclination.

2. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 1, characterized in that: The high-pressure water conveyance tunnel structure also includes a pre-set structural joint (4), and a pre-set fault staggered structure (3) passes through the pre-set structural joint (4) set along the seismogenic fault (1).

3. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 2, characterized in that: A waterproof seal is installed in the pre-designed structural joint (4).

4. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 1, 2, or 3, characterized in that: The bifurcation connection tunnel system (6) includes at least four connecting bifurcation tunnels (7) arranged in parallel along the water conveyance direction. The high-pressure water conveyance tunnel body (2) located at both ends of the tunnel widening section (5) is connected separately along the water conveyance direction through each connecting bifurcation tunnel (7).

5. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 4, characterized in that: Each connecting branch tunnel (7) includes at least one main connecting branch tunnel located at the bottom of the tunnel widening section (5).

6. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 5, characterized in that: Each connecting branch tunnel (7) is separated by concrete partition walls extending along the water conveyance direction.

7. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 6, characterized in that: There are six connecting branch tunnels (7) arranged in parallel along the water conveyance direction. The projection of the tunnel expansion section (5) in its cross-section is an ellipse with the major axis arranged horizontally. The six connecting branch tunnels (7) are arranged in two layers along the water conveyance direction in the tunnel expansion section (5). The two connecting branch tunnels (7) in the middle are the main connecting branch tunnels.

8. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 6, characterized in that: There are six connecting branch tunnels (7) arranged in parallel along the water conveyance direction. The projection of the tunnel expansion section (5) in its cross-section is an ellipse with its major axis arranged vertically. The six connecting branch tunnels (7) are arranged in two columns on the left and right sides along the water conveyance direction in the tunnel expansion section (5). The two connecting branch tunnels (7) in the middle are the main connecting branch tunnels.

9. The high-pressure water conveyance tunnel structure traversing a seismogenic fault according to claim 4, characterized in that: The projection of the tunnel expansion section (5) in its cross-section is a gate-shaped structure with a circular arc at the top. There are four connecting branch tunnels (7) arranged in parallel along the water conveyance direction. The center point of the four connecting branch tunnels (7) is arranged in a regular quadrilateral extending along the water conveyance direction within the tunnel expansion section (5).

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