Landslide repairing structure of built pressure tunnel with ventilation pipe arranged in mountain body

Abstract

The utility model relates to the technical field of tunnels in water conservancy and hydropower engineering, in particular to a landslide repairing structure of a built pressure tunnel with a ventilation pipe arranged in a mountain, which comprises the built pressure tunnel, an anchor-shotcrete 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 a cavity at the top of a collapse section can be exhausted along the ventilation structure when water passes through a main hole after collapse repairing, guarantee is provided for safe operation of the tunnel, and the structure 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 utility model relates to the technical field of tunnel engineering in water conservancy and hydropower projects, and particularly relates to a collapse repair structure for a built - pressure tunnel with a ventilation pipe arranged in a mountain body. Background Technique

[0002] With the continuous construction of water conservancy and hydropower projects in China, the tunnel engineering has developed rapidly. In water conservancy projects such as power generation water diversion, water supply and flood control, pressure tunnels are widely used. A considerable part of these pressure tunnels were built in the 20th century. At that time, in order to save investment, shotcrete support or secondary lining was not adopted for some tunnel sections with good surrounding rocks. After years of operation of the un - supported and unlined bare - rock tunnel sections, the rock mass may collapse due to softening when encountering water, or due to the large internal pressure in the tunnel and the air residue caused by the uneven inner surface leading to cavitation. For the collapse of pressure tunnels, if no timely measures are taken for repair, the cavity at the top of the tunnel caused by the collapse will always retain a large amount of air that cannot be discharged during the operation period, which will further cause more serious cavitation phenomena and lead to a larger - scale collapse.

[0003] The tunnels for water supply, power generation water diversion and flood control are related to people's livelihood or power generation benefits. The time requirement for maintenance and repair is often very short. If the conventional secondary lining or steel lining methods are used for repair, the construction time is often long, which cannot meet the requirement of quickly restoring the function. Therefore, it is necessary to propose a measure with simple construction, short construction period, safety and reliability.

[0004] Based on this, this case is proposed. Content of the Utility Model

[0005] The purpose of the utility model is to provide a collapse repair structure for a built - pressure tunnel with a ventilation pipe arranged in a mountain body, which has the characteristics of simple construction, short construction period, safety and reliability, and can meet the timely repair of the collapse of the built - pressure hydraulic tunnel.

[0006] In order to achieve the above purpose, the technical solution of the utility model is as follows:

[0007] A collapse repair structure for a built - pressure tunnel with a ventilation pipe arranged in a mountain body includes a bare - rock collapse section and conventional tunnel sections at the upstream and downstream of the bare - rock collapse section; it includes a ventilation structure arranged in the mountain body and above the bare - rock collapse section, one end of the ventilation structure is communicated with the top of the bare - rock collapse section, and the other end extends to the top of the mountain body and is communicated with the outside; the bare - rock collapse section is provided with an anchor - shotcrete support structure.

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

[0009] Furthermore, the shotcrete support structure includes initial shotcrete, steel mesh, shotcrete, systematic rock bolts and random drainage holes. The initial shotcrete, steel mesh and shotcrete are arranged from outside to inside on the side wall of the tunnel. The systematic rock bolts are arranged along the radial direction of the tunnel, and the random drainage holes are arranged at the sunken and seeping parts of the tunnel rock face.

[0010] Furthermore, the ventilation structure includes a ventilation pipe, a hole and a lining. The hole is opened from the top of the mountain to the top of the tunnel in the rock fall section of the bare rock. The ventilation pipe is inserted into the hole, and the lining 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 is made of concrete lining or cement mortar lining.

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

[0014] The advantages of the present utility model are as follows:

[0015] 1. Safe and reliable: By adopting the shotcrete support structure for the collapsed section of the existing pressure tunnel, the support stability of the collapsed section is ensured; by setting up the ventilation system, the problem that a large amount of air remains in the cavity at the top of the collapsed section and cannot be discharged is effectively solved, the cavitation phenomenon caused by the remaining air in the cavity and leading to a larger range of collapse is avoided, and the stability during the operation period is ensured; at the same time, the construction of the in-tunnel support structure is carried out step by step from one side to the other side, which also ensures the safety during the construction period.

[0016] 2. Simple construction and short construction period, with little impact on the project benefits: Only the shotcrete support structure and the ventilation structure repair measures are adopted for the collapsed section, and most of the ventilation structure can be completed before the emptying and repair. The cleaning of the collapsed rock slag, the shotcrete support structure at the bare rock collapsed section and the construction of the remaining ventilation structure can be carried out synchronously, effectively saving the repair time. Compared with the conventional repair measure of first clearing the slag and then carrying out secondary concrete lining, the construction period can be saved by more than 65%, and the impact on the subsequent project benefits such as water supply, power generation and flood control is small.

[0017] 3. Low project investment: The investment in the shotcrete support structure and the ventilation structure mainly involved in the present utility model is low. Compared with the conventional repair measure of first clearing the slag and then carrying out secondary concrete lining, the direct investment can be saved by more than 30%. If the indirect investment caused by the subsequent project benefits such as water supply or power generation is considered, the investment saving ratio will be higher. 4. Little impact on other inspection work of the tunnel: The construction of the shotcrete support structure and the ventilation structure mainly involved in the present utility model occupies a small space in the tunnel and takes a short time, and does not affect the implementation of other inspection work of the tunnel. During the repair construction of the collapsed section, the inspection of other positions of the tunnel can be carried out synchronously and corresponding repair measures can be taken. Description of the Drawings

[0018] Figure 1 is a schematic plan layout of a collapse repair structure of a built - in - mountain pressure tunnel with a vent pipe in an embodiment;

[0019] Figure 2 is a schematic longitudinal sectional view of a collapse repair structure of a built - in - mountain pressure tunnel with a vent pipe in an embodiment;

[0020] Figure 3 is Figure 1 and Figure 2 the A - A sectional view schematic diagram;

[0021] Figure 4 is Figure 2 and Figure 3 detail drawing A;

[0022] Figure 5 is Figure 2 and Figure 3 detail drawing B;

[0023] Figure 6 is Figure 1 and Figure 2 the B - B sectional view schematic diagram;

[0024] Figure 7 is Figure 1 and Figure 2 the C - C sectional view schematic diagram;

[0025] Label Description

[0026] 1. Built - in - mountain pressure tunnel; 11. Conventional tunnel section; 12. Rock - exposed collapse section; 13. Collapsed rock debris; 2. Shotcrete support structure; 21. Initial shotcrete; 22. Steel mesh; 23. Shotcrete; 24. System anchor bolt; 25. Random drainage hole; 3. Ventilation structure; 31. Vent pipe; 32. Pipe cap; 33. Hole wall; 34. Lining. Detailed Embodiment

[0027] The following further describes the present utility model in detail with reference to the embodiments. It should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. in the text are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0028] Such as Figures 1 to 7As shown in the figure, this embodiment proposes a collapse repair structure for a built - pressure tunnel with a ventilation pipe inside the mountain, which includes a built - pressure tunnel 1, an anchor - shotcrete support structure 2, and a ventilation structure 3. The built - pressure tunnel 1 includes a conventional tunnel section 11, a bare - rock collapse section 12, and collapse rock debris 13. The collapse rock debris 13 is located at the bottom of the bare - rock collapse section 12 and needs to be cleared during the collapse repair.

[0029] The anchor - shotcrete support structure 2 includes initial shotcrete 21, a steel mesh 22, shotcrete 23, systematic rock bolts 24, and random drainage holes 25. The initial shotcrete 21 is used for the initial support of the bare - rock collapse section 12 to reduce the risk of secondary collapse during the repair construction. The random drainage holes 25 should be arranged at the rock - surface depressions and seepage areas. The systematic rock bolts 24 are arranged along the radial direction of the tunnel and inserted into the mountain body.

[0030] 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 top of the bare - rock collapse section 12. The ventilation pipe 31 is inserted into the hole 33. The ventilation pipe 31 is vertically arranged above the bare - rock collapse section 12, with the top exposed on the mountain - top surface of the bare - rock collapse section 12 and the bottom located at the top of the bare - rock collapse section 12. To prevent sundries from entering the ventilation pipe 31, a pipe cap 32 is installed at 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.

[0031] S1. When a local bare - rock collapse section 12 is found to need repair during the routine inspection of the built - pressure tunnel 1, there is collapse rock debris at the bottom of the bare - rock collapse section at this time.

[0032] S2. The tunnel is filled with water and operates normally. At this time, the local bare - rock collapse section 12 detected previously is located, and a hole 33 is excavated in the upper mountain body. To ensure the normal lining of the ventilation pipe 31, the excavation depth of the hole 33 can stop when approaching the top of the bare - rock collapse section 12.

[0033] S3. The ventilation pipe 31 is buried and the lining body 34 is poured in the excavated hole 33.

[0034] S4. The built - pressure tunnel 1 is emptied, and the anchor - shotcrete support structure 2 is implemented for the bare - rock collapse section 12. At the same time, the collapse rock debris 13 is cleared, and a part of the ventilation structure 3 near the top of the bare - rock collapse section 12 and the pipe cap are constructed.

[0035] After the collapse repair is completed, when the existing pressure tunnel 1 is in water operation, the residual air in the cavity at the top of the bare rock collapse section 12 can be discharged along the air vent pipe 31 above the bare rock collapse section 12, thus avoiding cavitation caused by the residual air in the cavity at the top of the bare rock collapse section 12 and preventing further collapses. When the existing pressure tunnel 1 needs to be emptied for maintenance, the air vent pipe 31 can also supply air to the cavity at the top of the bare rock collapse section 12 in the reverse direction to prevent the rock mass at the top of the bare rock collapse section 12 from bearing additional adverse negative pressure when the existing pressure tunnel 1 discharges water.

[0036] The diameter and number of the air vent pipes 31 can be adjusted according to the actual ventilation requirements to meet the engineering needs. Preferably, the material of the air vent pipes 31 can be steel pipes, and at the same time, the inner surface of the steel pipes is subjected to anti-corrosion treatment.

[0037] To ensure the accuracy of the excavation of the holes 33 in a part of the ventilation structure 3 near the top of the bare rock collapse section 12, when the existing 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 at the top of the implemented ventilation structure 3, and then reaming construction can be carried out from inside the tunnel or from above.

[0038] The lining 34 can also be adjusted to a cement mortar lining or a concrete lining according to the actual size of the holes 33.

[0039] Preferably, the scope of the shotcrete support structure 2 at the bare rock collapse section 12 of the existing pressure tunnel 1 should be appropriately extended upstream and downstream to ensure the stability of the support.

[0040] Preferably, the collapsed rock debris 13 of the existing pressure tunnel 1 should be cleaned during the repair construction. The cleaning of the collapsed rock debris 13, the shotcrete support structure 2 at the bare rock collapse section 12, and the construction of a part of the ventilation structure 3 near the top of the bare rock collapse section 12 should be carried out synchronously, which can effectively save the emergency repair time.

[0041] Preferably, the shotcrete support structure 2 at the bare rock collapse section 12 should first be sprayed with initial concrete 21 on the overall collapsed surface to reduce the risk of re-collapse during the repair construction, then the steel mesh 22 is laid, and then the concrete 23 is sprayed.

[0042] Preferably, the shotcrete support structure 2 should be implemented step by step from the extended support scope on one side of the bare rock collapse section 12 to the other side to ensure that the construction personnel can construct on a safer working surface.

[0043] The above embodiments are only used to explain the concept of the present invention, rather than limiting the protection scope of the rights of the present invention. Any non-substantive modification made 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 provided 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.

Images