Tail water tunnel supporting structure for fault and surrounding rock fracture zone

Abstract

The utility model belongs to the technical field of pumped storage power station engineering, and particularly relates to a tailrace tunnel supporting structure for a fault and a surrounding rock fracture zone. A tailrace tunnel supporting structure for a fault and a surrounding rock broken zone comprises system anchor rods, reinforcing mesh shotcrete, a steel grating arch frame and a reinforced concrete lining, the system anchor rods are arranged in a plum blossom shape along the top arch range of a tailrace tunnel, the steel grating arch frame is arranged in the direction of the tailrace tunnel, and a plurality of reinforcing steel pull rods are arranged on the inner side of the steel grating arch frame; the steel grating arch frames are connected through steel bar pull rods, reinforced concrete linings are arranged on the inner walls of the steel grating arch frames, and a plurality of permanent seams are formed in the reinforced concrete linings at intervals in the range of penetrating through a fault and a surrounding rock fracture zone. The supporting structure can provide enough supporting strength for the tailrace tunnel, effectively control deformation of surrounding rocks, adapt to complex geological conditions such as faults and surrounding rock fracture zones and improve the construction safety of the tailrace tunnel under unstable geological conditions.

Description

Technical Field

[0001] The utility model belongs to the technical field of pumped-storage power station engineering, and particularly relates to a tailrace tunnel support structure for faults and surrounding rock fracture zones. Background Art

[0002] At present, during the construction of pumped-storage power stations, especially in the construction of underground water conveyance tunnels, various geological problems are often encountered, including multiple adverse factors such as faults, fractures, and rock mass fragmentation. The rock mass usually becomes fragmented, with well-developed structural planes, low rock mass strength, and abundant groundwater, which increases the surrounding rock pressure and further reduces the self-stabilizing ability. All these pose threats to the stability and safety of the project.

[0003] For tailrace tunnels with faults and surrounding rock fracture zones, existing support methods often have difficulty in effectively dealing with them, unable to form a continuous and stable support system, with low construction efficiency and high safety risks. In addition, when dealing with fracture zones, existing methods often lack targeted reinforcement measures, resulting in insufficient interaction between the support structure and the surrounding rock, unable to effectively transfer and disperse stress, thus increasing the burden on the support structure and reducing the support effect. Summary of the Utility Model

[0004] Aiming at the above problems, the purpose of the utility model is to provide a tailrace tunnel support structure for faults and surrounding rock fracture zones, which can provide sufficient support strength for the tailrace tunnel, effectively control the deformation of the surrounding rock, and can adapt to complex geological conditions such as faults and surrounding rock fracture zones, improving the construction safety, support effect, and long-term stability of the structure of the tailrace tunnel under unstable geological conditions.

[0005] The technical solution of the utility model lies in: a tailrace tunnel support structure for faults and surrounding rock fracture zones, including systematic bolts, shotcrete with wire mesh, steel grid arch frames, and reinforced concrete linings. The systematic bolts are arranged in a plum blossom pattern along the crown range of the tailrace tunnel. The steel grid arch frames are arranged along the direction of the tailrace tunnel. A number of steel bars are arranged inside the steel grid arch frames, and each bay of the steel grid arch frames is connected by the steel bars. The inner wall of the steel grid arch frames is provided with reinforced concrete linings, and a plurality of permanent joints are arranged at intervals within the range of passing through faults and surrounding rock fracture zones in the reinforced concrete linings.

[0006] Hollow grouting foot bolts are respectively arranged at the lower parts on both sides of the steel grid arch frames.

[0007] The systematic bolts are cement mortar bolts with a diameter of 25 mm and a length of 4.5 m, and the spacing between adjacent systematic bolts is 1.0 m × 1.0 m.

[0008] The shotcrete with wire mesh includes a wire mesh and concrete. The diameter of the wire mesh is 8 mm, and the spacing of the wire mesh is 15 cm × 15 cm. The concrete is C25 concrete, and the thickness of the concrete is 25 cm.

[0009] The distance between adjacent steel grid arches is 0.75 m, and a permanent joint is provided every 3 m for the reinforced concrete lining within the range of passing through faults and surrounding rock fracture zones.

[0010] Two rubber water stops and one copper water stop are arranged in the permanent joint.

[0011] The technical effects of the present utility model are as follows: 1. The combined support structure of systematic bolts, shotcrete with wire mesh, steel grid arches and reinforced concrete lining in the present utility model is applicable to the support structure and method of the tailrace tunnel under the conditions of faults and surrounding rock fracture zones, for the surrounding rock fracture areas with poor geological conditions and many geological problems; 2. Through the interaction between the surrounding rock and the support structure, the stress of the tailrace tunnel support structure of the present utility model can be effectively dispersed and transmitted, avoiding the separate stress of the support structure, enhancing the support effect, forming a stable stress circle, thus constituting a continuous and stable support system, and improving the safety and reliability during the construction process.

[0012] The following will be further described with reference to the drawings. Brief Description of the Drawings

[0013] Figure 1 It is a sectional structure diagram of a support structure for a tailrace tunnel in a fault and surrounding rock fracture zone according to an embodiment of the present utility model.

[0014] Figure 2 It is a side view of a support structure for a tailrace tunnel in a fault and surrounding rock fracture zone according to an embodiment of the present utility model.

[0015] Reference Signs: 1 - Systematic bolt; 2 - Shotcrete with wire mesh; 3 - Steel grid arch; 4 - Hollow grouting foot-locking bolt; 5 - Reinforced concrete lining; 6 - Fault and surrounding rock fracture zone; 7 - Permanent joint. Detailed Description of the Embodiment Embodiment 1

[0016] As Figure 1 、 Figure 2As shown in the figure, a support structure for a tailrace tunnel in a fault and surrounding rock fracture zone includes a systematic bolt 1, shotcrete with wire mesh 2, a steel grid arch 3, and a reinforced concrete lining 5. The systematic bolts 1 are arranged in a plum blossom pattern along the crown area of the tailrace tunnel. The steel grid arches 3 are arranged along the direction of the tailrace tunnel. A number of steel tie rods are provided inside the steel grid arches 3, and each steel grid arch 3 is connected by the steel tie rods. The inner wall of the steel grid arch 3 is provided with a reinforced concrete lining 5, and a number of permanent joints 7 are provided at intervals within the range of passing through the fault and surrounding rock fracture zone 6 of the reinforced concrete lining 5.

[0017] During actual use, when the tailrace tunnel of the present utility model passes through the fault and surrounding rock fracture zone 6, shotcrete with wire mesh 2 is hung in the crown area of the tunnel, and at the same time, systematic bolts 1 are arranged. A steel grid arch 3 is fixedly arranged at intervals along the axis direction of the tunnel, and the two side arch feet are fixed, and steel tie rods are arranged inside, so that each steel grid arch 3 is connected to each other through the steel tie rods. A reinforced concrete lining 5 is arranged inside the steel grid arch 3 to provide internal support for the excavated tunnel. A permanent joint 7 is fixedly arranged at intervals on the reinforced concrete lining 5, so that the displacement generated by the broken surrounding rock on the tunnel body can be more evenly distributed. Rubber waterstops and copper waterstops are arranged in the permanent joint 7 to prevent external water from seeping in. The reinforced concrete lining 5 inside the steel grid arch 3 of the present utility model provides internal support for the excavated tunnel, enabling the interaction and stress transfer between the surrounding rock, the steel grid arch, and the concrete lining, forming a stable stress-bearing circle in the tunnel, jointly bearing the deformation generated by the broken surrounding rock, and constituting an overall support system. The combined support structure of the systematic bolt, shotcrete with wire mesh, steel grid arch, and reinforced concrete lining of the present utility model is applicable to the support structure and method of the tailrace tunnel under the conditions of the fault and surrounding rock fracture zone, which is a surrounding rock fracture area with poor geological conditions and many geological problems. The support structure of the tailrace tunnel of the present utility model enables the stress to be effectively dispersed and transferred through the interaction between the surrounding rock and the support structure, avoids the separate stress of the support structure, enhances the support effect, forms a stable stress-bearing circle, and thus constitutes a continuous and stable support system, improving the safety and reliability during the construction process. Embodiment 2

[0018] Preferably, on the basis of Embodiment 1, in this embodiment, hollow grouting foot-locking bolts 4 are respectively provided at the lower parts on both sides of the steel grid arch 3.

[0019] During actual use, hollow grouting foot-locking bolts 4 are respectively arranged at the lower parts on both sides of the steel grid arch 3 of the utility model. The hollow grouting foot-locking bolts 4 fix the steel grid arch 3. In the fault and surrounding rock fracture zone, the rock mass is broken, the fissures are dense, and the structure is developed. The hollow grouting foot-locking bolts 4 not only play the role of anchoring and connecting the steel grid arch and the surrounding rock, but also play the role of grouting and consolidating the rock mass fissures around the bolts, effectively improving the rock strength and enhancing the structural stability. In case of deformation and collapse of the broken surrounding rock, the steel grid arch 3 can effectively bear and disperse the load brought by the rock deformation through its own high strength and stiffness, and reduce the deformation of the tunnel to a certain extent. Example 3

[0020] Preferably, on the basis of Example 1 or Example 2, in this embodiment, the systematic bolt 1 is a cement mortar bolt. The diameter of the systematic bolt 1 is 25 mm, the length is 4.5 m, and the spacing between adjacent systematic bolts 1 is 1.0 m × 1.0 m.

[0021] During actual use, the systematic bolt 1 of the utility model is a cement mortar bolt. The diameter of the systematic bolt 1 is 25 mm, the length is 4.5 m, and the spacing between adjacent systematic bolts 1 is 1.0 m × 1.0 m, ensuring the overall stability of the support structure. Example 4

[0022] Preferably, on the basis of Example 1 or Example 3, in this embodiment, the shotcrete with steel mesh 2 includes a steel mesh and concrete. The diameter of the steel mesh is 8 mm, the spacing of the steel mesh is 15 cm × 15 cm, the concrete is C25 concrete, and the thickness of the concrete is 25 cm.

[0023] During actual use, the shotcrete with steel mesh 2 of the utility model includes a steel mesh and concrete. The diameter of the steel mesh is 8 mm, the spacing of the steel mesh is 15 cm × 15 cm, the concrete is C25 concrete, and the thickness of the concrete is 25 cm, preliminarily sealing and strengthening the rock in the fault and surrounding rock fracture zone 6 area to prevent local collapse and spalling. Example 5

[0024] Preferably, on the basis of Example 1 or Example 4, in this embodiment, the distance between adjacent steel grid arches 3 is 0.75 meters, and a permanent joint 7 is arranged every 3 meters in the range where the reinforced concrete lining 5 crosses the fault and surrounding rock fracture zone 6.

[0025] During actual use, the utility model enables the displacement generated by the broken surrounding rock on the tunnel body to be more evenly distributed, avoiding large local dislocation and cracking. Example 6

[0026] Preferably, on the basis of Embodiment 1 or Embodiment 5, in this embodiment, two rubber water stops and one copper water stop are arranged in the permanent joint 7.

[0027] During actual use, the rubber water stop and the copper water stop are arranged between the permanent joints 7 of the present utility model to prevent external water from infiltrating into the interior.

[0028] A tailrace tunnel support structure for faults and surrounding rock fracture zones includes the following steps when in use:

[0029] S1: When the tailrace tunnel passes through the fault and the surrounding rock fracture zone 6, a steel mesh shotcrete 2 is hung in the top arch range of the tunnel, and system bolts 1 are arranged at the same time;

[0030] S2: A steel grid arch frame 3 is fixedly arranged at intervals along the tunnel axis direction, the two arch feet are fixed, and steel bars are arranged on the inner side, so that each steel grid arch frame 3 is connected to each other through the steel bars;

[0031] S3: A reinforced concrete lining 5 is arranged on the inner side of the steel grid arch frame 3 to provide internal support for the excavated tunnel;

[0032] S4: A permanent joint 7 is fixedly arranged at intervals on the reinforced concrete lining 5, so that the displacement generated by the fractured surrounding rock to the tunnel body can be more evenly distributed, and a rubber water stop and a copper water stop are arranged in the permanent joint 7 to prevent external water from infiltrating into the interior.

[0033] The above is only the preferred specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model.

Claims

1. A tailrace tunnel support structure for faults and surrounding rock fracture zones, characterized in that: It includes system bolts (1), shotcrete with wire mesh (2), steel grid arches (3) and reinforced concrete linings (5). The system bolts (1) are arranged in a plum blossom pattern along the crown area of the tailrace tunnel. The steel grid arches (3) are arranged along the direction of the tailrace tunnel. A number of steel bars are arranged inside the steel grid arches (3). Each bay of the steel grid arches (3) is connected by the steel bars. The inner wall of the steel grid arches (3) is provided with a reinforced concrete lining (5). The reinforced concrete lining (5) is provided with a plurality of permanent joints (7) at intervals within the range of passing through the fault and surrounding rock fractured zone (6).

2. The tailrace tunnel support structure for faults and surrounding rock fracture zones according to claim 1, wherein: Hollow grouting foot bolts (4) are respectively arranged at the lower parts on both sides of the steel grid arches (3).

3. The tailrace tunnel support structure for faults and surrounding rock fracture zones according to claim 1, characterized in that: The system bolts (1) are cement mortar bolts. The diameter of the system bolts (1) is 25 mm and the length is 4.5 m. The row and column spacing of adjacent system bolts (1) is 1.0 m × 1.0 m.

4. The tailrace tunnel support structure for faults and surrounding rock fracture zones according to claim 1, characterized in that: The shotcrete with wire mesh (2) includes a wire mesh and concrete. The diameter of the wire mesh is 8 mm and the spacing of the wire mesh is 15 cm × 15 cm. The concrete is C25 concrete and the thickness of the concrete is 25 cm.

5. The tailrace tunnel support structure for fault and surrounding rock fracture zones according to claim 1, characterized in that: The distance between adjacent steel grid arches (3) is 0.75 m. The reinforced concrete lining (5) is provided with a permanent joint (7) every 3 m within the range of passing through the fault and surrounding rock fractured zone (6).

6. The tailrace tunnel support structure for faults and surrounding rock fracture zones according to claim 1, characterized in that: Two rubber water stops and one copper water stop are arranged in the permanent joint (7).

Images