Repairing structure and repairing method for landslide of built pressure tunnel with ventilation pipe arranged in mountain

Abstract

The invention relates to the technical field of tunnels in water conservancy and hydropower engineering, in particular to a landslide repairing structure and method for a built pressure tunnel with a ventilation pipe arranged in a mountain, the landslide repairing structure comprises the built pressure tunnel, an anchoring and shotcreting supporting structure and a ventilation structure, and the built pressure tunnel comprises a conventional tunnel section, a bare rock landslide section and landslide rock ballast; the anchor-shotcrete supporting structure comprises primary shotcrete, a reinforcing mesh, shotcrete, a system anchor rod and a random drainage hole, and safety and stability of collapse section supporting are guaranteed. The ventilation structure comprises a ventilation pipe, a pipe cap, a hole wall and lining concrete; the collapse repairing workload is small, construction is easy and convenient, the investment cost is saved, the construction period is shortened, air in the cavity of the top of the collapse section can be exhausted along the ventilation structure when water is introduced into the main hole after collapse repairing, guarantee is provided for safe operation of the tunnel, and the method has the advantages of being easy and convenient to construct, short in construction period, safe, reliable and low in investment. And the timely repair of the collapse of the built pressure hydraulic tunnel can be met.

Description

Technical Field

[0001] The invention relates to the technical field of tunnels in water conservancy and hydropower engineering, and in particular to a landslide repair structure and a repair method for an existing pressure tunnel with a ventilation pipe arranged in a mountain. Background Art

[0002] With the continuous construction of water conservancy and hydropower projects in my country, tunnel engineering has developed rapidly. In water conservancy projects such as power generation, water diversion, water supply and flood control, pressurized tunnels are widely used. A considerable number of these pressurized tunnels were built in the 20th century. At that time, in order to save investment, some tunnel sections with better surrounding rock did not use shotcrete support or secondary lining. After years of operation, the bare rock tunnel sections without support and lining may cause landslides due to softening by water, or due to the high internal pressure of the tunnel and the uneven inner surface, the residual air causes cavitation and then causes landslides. For the collapse of pressurized tunnels, if measures are not taken in time to repair them, a large amount of air will remain in the cavity on the top of the cave caused by the collapse and cannot be discharged during the operation period, which will cause more serious cavitation and lead to landslides on a larger scale.

[0003] Tunnels used for water supply, power generation and flood control are related to people's livelihood or power generation benefits, and often require very short time for inspection and repair. If conventional secondary lining or steel lining methods are used for repair, the construction time is often long and cannot meet the needs of timely restoration of functions. Therefore, it is necessary to propose a measure that is simple to construct, short in construction period, safe and reliable.

[0004] Based on this, this case is brought forward. Summary of the invention

[0005] One of the purposes of the present invention is to provide a structure for repairing collapse of an existing hydraulic tunnel with a ventilation pipe in a mountain, which has the characteristics of simple construction, short construction period, safety and reliability, and can meet the needs of timely repairing collapse of an existing hydraulic tunnel.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A structure for repairing collapse of a pressure tunnel with a ventilation pipe in a mountain, comprising a bare rock collapse section and conventional tunnel sections located upstream and downstream of the bare rock collapse section; comprising a ventilation structure arranged in the mountain and above the bare rock collapse section, one end of the ventilation structure being connected to the cave roof of the bare rock collapse section, and the other end extending to the top of the mountain and connected to the outside; an anchor spraying support structure is arranged in the bare rock collapse section.

[0008] Furthermore, the anchor-spraying support structure of the bare rock collapse section extends to the conventional tunnel sections of the upstream and downstream sections.

[0009] Furthermore, the anchor-sprayed support structure includes primary sprayed concrete, steel mesh, sprayed concrete, system anchor rods and random drainage holes. The primary sprayed concrete, steel mesh and sprayed concrete are arranged from the outside to the inside on the side wall of the tunnel, the system anchor rods are arranged radially along the tunnel, and the random drainage holes are arranged in the depressions and seepage areas of the tunnel rock surface.

[0010] Furthermore, the ventilation structure includes a ventilation pipe, a hole and a lining body, the hole is opened from the top of the mountain to the top of the cave in the bare rock collapse section, the ventilation pipe is inserted into the hole, and the lining body is arranged between the inner wall of the hole and the outer wall of the ventilation pipe.

[0011] Furthermore, a pipe cap is provided at one end of the ventilation pipe located at the top of the mountain.

[0012] Furthermore, the lining body is made of concrete lining or cement mortar lining.

[0013] Furthermore, the ventilation pipe is made of a steel pipe, and an anti-corrosion layer is provided on the inner wall of the steel pipe.

[0014] The second object of the present invention is to provide a method for repairing a collapsed structure of a pressure tunnel having a ventilation pipe installed in the mountain, comprising the following steps:

[0015] S1. A routine inspection of an existing pressure tunnel found that a local bare rock collapse section needed to be repaired. At this time, there was collapse slag at the bottom of the bare rock collapse section;

[0016] S2. The tunnel is running normally with water, and the local bare rock collapse section found during the inspection is located. A hole is excavated downward at the top of the mountain above the local bare rock collapse section, and the hole excavation stops when it is close to the top of the bare rock collapse section;

[0017] S3. Insert the vent pipe into the hole and cast the lining to fix it;

[0018] S4. The tunnel is shut down and emptied, and the anchor-spraying support structure is constructed for the bare rock collapse section and its upstream and downstream extensions, the collapse debris is cleaned, and the ventilation structure is constructed near the cave top of the bare rock collapse section and the pipe cap on the ventilation pipe. The anchor-spraying support structure should first be sprayed with initial concrete on the overall collapse side;

[0019] The cleaning of collapsed rock debris, the construction of the anchor-sprayed support structure, and the construction of the ventilation structure near the cave top of the bare rock collapsed section were carried out simultaneously.

[0020] Furthermore, the construction of the ventilation structure near the top of the bare rock collapse section includes the following steps: when the built pressure tunnel is emptied for emergency repair, a small drill bit is used to drill through the entire hole from top to bottom from the top of the implemented ventilation structure, and then the hole expansion construction is carried out from inside or above the bare rock collapse section.

[0021] Furthermore, the anchor-spray support structure should be implemented gradually from the extended support range on one side of the bare rock collapse section to the other side.

[0022] The advantages of the present invention are:

[0023] 1. Safe and reliable: The anchor-spray support structure is adopted for the collapsed section of the pressure tunnel to ensure the support stability of the collapsed section; the ventilation system is set up to effectively solve the problem that a large amount of air remains in the cavity at the top of the collapsed section and cannot be discharged, thus avoiding the cavitation phenomenon caused by the residual air in the cavity and causing a larger range of collapse, ensuring the stability during the operation period; at the same time, the construction of the support structure in the tunnel is carried out step by step from one side to the other, which also ensures the safety during the construction period;

[0024] 2. The construction is simple and the construction period is short, with little impact on the project benefits: the collapse section only adopts the repair measures of anchor spraying support structure and ventilation structure, and most of the ventilation structure can be completed before the emptying repair. The cleaning of the collapse slag, the anchor spraying support structure at the bare rock collapse section and the construction of the remaining ventilation structure can be carried out simultaneously, which effectively saves the repair time. Compared with the conventional repair measures of first cleaning the slag and then carrying out the secondary concrete lining, it can save more than 65% of the construction period, and has little impact on the subsequent water supply, power generation and flood control engineering benefits;

[0025] 3. Low project investment: The anchor-sprayed support structure and ventilation structure mainly involved in the present invention have low investment, and can save about 30% or more of direct investment compared with the conventional repair measures of first clearing the slag and then carrying out secondary concrete lining. If the indirect investment caused by subsequent engineering benefits such as water supply or power generation is considered, the proportion of investment savings will be even higher; 4. Little impact on other maintenance work of the tunnel: The anchor-sprayed support structure and ventilation structure mainly involved in the present invention occupy a small space in the tunnel and take a short time to construct, which does not affect the implementation of other maintenance work of the tunnel. During the repair construction of the collapsed section, other locations of the tunnel can be inspected and corresponding repair measures can be taken simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the plan layout of a pressure tunnel collapse repair structure with a ventilation pipe installed in a mountain in an embodiment;

[0027] Figure 2 It is a longitudinal section schematic diagram of a built pressure tunnel collapse repair structure with a ventilation pipe in a mountain in an embodiment;

[0028] Figure 3 yes Figure 1 and Figure 2 A-A cross-sectional schematic diagram;

[0029] Figure 4 yes Figure 2 and Figure 3 Detailed drawing A;

[0030] Figure 5 yes Figure 2 and Figure 3 Detailed drawing B;

[0031] Figure 6 yes Figure 1 and Figure 2 B-B cross-sectional view of FIG.

[0032] Figure 7 yes Figure 1 and Figure 2 C-C cross-sectional schematic diagram;

[0033] Description of symbols

[0034] 1. Existing pressure tunnel; 11. Conventional tunnel section; 12. Bare rock collapse section; 13. Collapsed slag; 2. Anchor spraying support structure; 21. Primary spraying concrete; 22. Steel mesh; 23. Spraying concrete; 24. System anchor rod; 25. Random drainage hole; 3. Ventilation structure; 31. Ventilation pipe; 32. Pipe cap; 33. Hole wall; 34. Lining body. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the embodiments. It should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" herein are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0036] like Figure 1 to Figure 7 As shown, this embodiment proposes a structure for repairing collapse of an existing pressure tunnel with a ventilation pipe in a mountain, comprising an existing pressure tunnel 1, an anchor spraying support structure 2 and a ventilation structure 3. The existing pressure tunnel 1 comprises a conventional tunnel section 11, a bare rock collapse section 12 and collapse slag 13, and the collapse slag 13 is located at the bottom of the bare rock collapse section 12 and needs to be cleaned during the collapse repair.

[0037] The anchor spraying support structure 2 includes primary spraying concrete 21, steel mesh 22, spraying concrete 23, system anchor rods 24 and random drainage holes 25. The primary spraying concrete 21 is used for the initial support of the bare rock collapse section 12 to reduce the risk of collapse again during repair construction. The random drainage holes 25 should be arranged at the depressions and seepage points of the rock surface. The system anchor rods 24 are arranged along the radial direction of the tunnel and inserted into the mountain.

[0038] The ventilation structure 3 includes a ventilation pipe 31, a pipe cap 32, a hole 33 and a lining body 34. The hole 33 is opened from the top of the mountain to the cave top of the bare rock collapse section 12, and the ventilation pipe 31 is inserted into the hole 33. The ventilation pipe 31 is vertically arranged on the upper part of the bare rock collapse section 12, with the top exposed to the mountain top surface of the bare rock collapse section 12 and the bottom located at the cave top of the bare rock collapse section 12. To prevent debris from entering the ventilation pipe 31, a pipe cap 32 is provided on the top of the ventilation pipe 31. To ensure the stability of the ventilation pipe 31, a lining body 34 is filled between the ventilation pipe 31 and the hole 33.

[0039] S1. When a routine inspection of the built pressure tunnel 1 is conducted, it is found that a local bare rock collapse section 12 needs to be repaired. At this time, there is collapse slag at the bottom of the bare rock collapse section;

[0040] S2. The tunnel is running normally. At this time, the local bare rock collapse section 12 detected before is located, and a hole 33 is excavated in the upper part of the mountain. To ensure the normal lining of the vent pipe 31, the depth of the excavation of the hole 33 can be stopped when it is close to the top of the bare rock collapse section 12;

[0041] S3. The excavated hole 33 is buried with the ventilation pipe 31 and the lining body 34 is poured;

[0042] S4. Empty the existing pressure tunnel 1, implement the anchor spraying support structure 2 on the bare rock collapse section 12, clean up the collapse slag 13 and construct a ventilation structure 3 near the top of the bare rock collapse section 12 and the pipe cap;

[0043] After the collapse repair is completed, when the built pressure tunnel 1 is put into operation, the residual air in the cave top cavity of the bare rock collapse section 12 can be discharged along the vent pipe 31 on the upper part of the bare rock collapse section 12, thereby preventing the residual air in the cave top cavity of the bare rock collapse section 12 from inducing cavitation and causing further collapse. When the built pressure tunnel 1 needs to be emptied for maintenance, the vent pipe 31 can also reversely supply air to the cave top cavity of the bare rock collapse section 12 to prevent the rock mass on the cave top of the bare rock collapse section 12 from being subjected to additional adverse negative pressure when the built pressure tunnel 1 is drained.

[0044] The diameter and number of the ventilation pipes 31 can be adjusted according to actual ventilation requirements to meet engineering requirements. Preferably, the material of the ventilation pipe 31 can be a steel pipe, and the inner surface of the steel pipe is treated with anti-corrosion.

[0045] In order to ensure the accuracy of excavation of the hole 33, a part of the ventilation structure 3 is close to the top of the bare rock collapse section 12. When the built pressure tunnel 1 is emptied for emergency repair, a small drill bit can be used to drill through the entire hole 33 from top to bottom from the top of the implemented ventilation structure 3, and then the hole expansion construction can be carried out from inside the hole or from the top.

[0046] The lining body 34 can also be adjusted to cement mortar lining or concrete lining according to the actual size of the hole 33 .

[0047] Preferably, the range of the anchor-spray support structure 2 at the bare rock collapse section 12 of the existing pressure tunnel 1 should be appropriately extended upward and downstream to ensure the stability of the support.

[0048] Preferably, the landslide debris 13 of the built pressure tunnel 1 should be cleaned during the repair construction, and the cleaning of the landslide debris 13, the anchor spraying support structure 2 at the bare rock landslide section 12, and the construction of a part of the ventilation structure 3 near the top of the bare rock landslide section 12 should be carried out simultaneously, which can effectively save the repair time.

[0049] Preferably, the anchor spraying support structure 2 at the bare rock collapse section 12 should first be sprayed with initial concrete 21 on the overall collapse side to reduce the risk of collapse again during repair construction, and then a steel mesh 22 should be laid, followed by spraying concrete 23.

[0050] Preferably, the anchor spraying support structure 2 should be implemented gradually from the extended support range on one side of the bare rock collapse section 12 to the other side to ensure that the implementation personnel construct in a safer working surface.

[0051] The above embodiments are only used to explain the concept of the present invention, rather than to limit the protection of the rights of the present invention. Any non-substantial changes to the present invention using this concept shall fall within the protection scope of the present invention.

Claims

1. A structure for repairing collapse of a pressure tunnel with a ventilation pipe installed in a mountain, comprising a bare rock collapse section and conventional tunnel sections located upstream and downstream of the bare rock collapse section, characterized in that: It includes a ventilation structure arranged in the mountain and located above the bare rock collapse section, one end of the ventilation structure is connected to the cave top of the bare rock collapse section, and the other end extends to the top of the mountain and connected to the outside; the bare rock collapse section is provided with an anchor spraying support structure.

2. A structure for repairing collapse of an existing pressure tunnel with a ventilation pipe in a mountain as claimed in claim 1, characterized in that: The anchor-spray support structure of the bare rock collapse section extends to the conventional tunnel sections of the upstream and downstream sections.

3. A structure for repairing collapse of an existing pressure tunnel with a ventilation pipe in a mountain as claimed in claim 1 or 2, characterized in that: The anchor-sprayed support structure includes primary sprayed concrete, steel mesh, sprayed concrete, system anchor rods and random drainage holes. The primary sprayed concrete, steel mesh and sprayed concrete are arranged from the outside to the inside on the side wall of the tunnel, the system anchor rods are arranged along the radial direction of the tunnel, and the random drainage holes are arranged in the depressions and seepage areas of the rock surface of the tunnel.

4. A structure for repairing collapse of an existing pressure tunnel with a ventilation pipe in a mountain as claimed in claim 1, characterized in that: The ventilation structure includes a ventilation pipe, a hole and a lining body. The hole is opened from the top of the mountain to the top of the cave in the bare rock collapse section. The ventilation pipe is inserted into the hole. The lining body is arranged between the inner wall of the hole and the outer wall of the ventilation pipe.

5. A structure for repairing collapse of an existing pressure tunnel with a ventilation pipe in a mountain as claimed in claim 4, characterized in that: A pipe cap is arranged at one end of the ventilation pipe located at the top of the mountain.

6. A structure for repairing collapse of an existing pressure tunnel with a ventilation pipe in a mountain as claimed in claim 4, characterized in that: The lining body is made of concrete lining or cement mortar lining.

7. A structure for repairing collapse of an existing pressure tunnel with a ventilation pipe in a mountain as claimed in claim 4, characterized in that: The ventilation pipe is made of a steel pipe, and an anti-corrosion layer is arranged on the inner wall of the steel pipe.

8. A method for repairing a collapsed structure of a pressure tunnel with a ventilation pipe installed in a mountain according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. A routine inspection of an existing pressure tunnel found that a local bare rock collapse section needed to be repaired. At this time, there was collapse slag at the bottom of the bare rock collapse section; S2. The tunnel is running normally with water, and the local bare rock collapse section found during the inspection is located. A hole is excavated downward at the top of the mountain above the local bare rock collapse section, and the hole excavation stops when it is close to the top of the bare rock collapse section; S3. Insert the vent pipe into the hole and cast the lining to fix it; S4. The tunnel is shut down and emptied, and the anchor-spraying support structure is constructed for the bare rock collapse section and its upstream and downstream extensions, the collapse debris is cleaned, and the ventilation structure is constructed near the cave top of the bare rock collapse section and the pipe cap on the ventilation pipe. The anchor-spraying support structure should first be sprayed with initial concrete on the overall collapse side; The cleaning of collapsed rock debris, the construction of the anchor-sprayed support structure, and the construction of the ventilation structure near the cave top of the bare rock collapsed section were carried out simultaneously.

9. A method for repairing a collapsed structure of a pressure tunnel with a ventilation pipe installed in a mountain as claimed in claim 8, characterized in that: The construction of the ventilation structure near the top of the bare rock collapse section includes the following steps: when the existing pressure tunnel is emptied for emergency repair, a small drill bit is used to drill through the entire hole from top to bottom from the top of the implemented ventilation structure, and then the hole expansion construction is carried out from inside or above the bare rock collapse section.

10. A method for repairing a collapsed structure of a pressure tunnel with a ventilation pipe installed in a mountain as claimed in claim 8, characterized in that: The anchor-spray support structure should be implemented gradually from the extended support range on one side of the bare rock collapse section to the other side.

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