Safe construction method for pumped storage power station tunnel in inclined rock stratum

Abstract

The invention relates to the technical field of pumped storage power stations, in particular to a safe construction method for an inclined rock stratum pumped storage power station tunnel. Firstly, the half side with the relatively high inclination is excavated from bottom to top, the excavated inclined rock stratum is supported through the pipe shed pipe before excavation, the inclined rock stratum can be prevented from sliding towards the excavated tunnel area under the action of the gravity of the inclined rock stratum through cooperation with the supporting effect of the steel arch frame, the bottom plate steel frame and the hydraulic supporting columns, and the rock stratum movement is effectively controlled; the bottom-to-top excavation facilitates the falling of the rock stratum and also facilitates the supporting of the hydraulic prop. Then the half side with the relatively low inclination is excavated from top to bottom, the stability of the half side rock stratum with the relatively low inclination is guaranteed, the steel arch is supported in time during excavation, and it is guaranteed that the steel arch and the bottom plate steel frame are constructed in time in the excavated tunnel area after each rock stratum is excavated; the steel arch frame and the bottom plate steel frame in the excavated tunnel area can be closed in time, and the whole section can be closed to form a ring in time after being excavated. The construction is simple, and popularization is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of pumped - storage power stations, and more specifically, to a method for safe construction of tunnels in an inclined - rock - layer pumped - storage power station. Background Art

[0002] Pumped - storage power stations have the advantages of mature technology, fast and flexible response, large single - unit capacity, and good economy. They can effectively relieve the system peak - shaving pressure, quickly and stably regulate the system frequency, operate in a phase - regulating mode, stabilize the system voltage. They are the accident standby power supply of the power system and can be used as the grid black - start power supply, being the first choice for large - scale energy regulation.

[0003] Pumped - storage power stations are generally built in mountainous areas, using natural valleys or abandoned mine pits after open - pit mining as water - storage reservoirs. The pumped - storage power station also includes a tunnel group project for connecting the water - storage reservoir. Since the tunnel group contains tunnels with various functions, the cross - section shapes and sizes of the tunnels are not consistent. And due to the influence of the tunnel length and the transportation problem of construction equipment, it is difficult to construct the tunnel group using integrated construction equipment such as shield machines. The tunnel group needs to maintain long - term stability, so it is necessary to select as much as possible in stable rock layers. However, the rock layers are affected by geological activities and many show inclined attitudes. When constructing tunnels in inclined rock layers, they are easily affected by the bias pressure of the rock layers. Therefore, how to safely and efficiently construct tunnels in inclined rock layers has become a difficult problem to be solved in this field. Summary of the Invention

[0004] In view of the above - mentioned technical problems, the present invention provides a method for safe construction of tunnels in an inclined - rock - layer pumped - storage power station. The tunnels of the pumped - storage power station are constructed along the strike of the inclined rock layer, and the method includes the following steps:

[0005] a. On the relatively higher - side of the dip of the tunnel, a number of pipe - shed pipes are constructed at intervals along the designed contour line of the tunnel. The pipe - shed pipes are constructed along the strike of the inclined rock layer, and one pipe - shed pipe is constructed for each layer of inclined rock layer.

[0006] b. Gradually construct the relatively higher - side of the dip of the tunnel along the strike. The construction content of each step includes: excavating the inclined rock layer layer by layer from bottom to top, and immediately using hydraulic props to support the pipe - shed pipes in the just - excavated inclined rock layer after each excavation of an inclined rock layer; promptly supporting the side cross - section of the exposed tunnel with steel arch frames, and promptly supporting the bottom of the exposed tunnel with floor steel frames; connecting the steel arch frames and the floor steel frames circumferentially, and connecting the steel arch frames and the adjacent pipe - shed pipes circumferentially. A hydraulic support is used to support on the central symmetry line of the tunnel, and the hydraulic support supported on the central symmetry line of the tunnel, the steel arch frames, the floor steel frames, and the pipe - shed pipes are closed into a ring.

[0007] c. Along the relatively high side of the inclination of the lagging tunnel, gradually construct the relatively low side of the inclination of the tunnel along the trend. Each construction step includes: on the relatively low side of the inclination of the tunnel, excavate the inclined rock strata layer by layer from top to bottom. After each excavation of an inclined rock strata layer, immediately support the exposed side section of the tunnel with steel arch frames in a timely manner and connect them with the steel arch frames already constructed on the relatively high side of the inclination of the tunnel; support the exposed bottom surface of the tunnel with floor steel frames in a timely manner and connect them with the steel arch frames and floor steel frames already constructed in the same ring; remove the hydraulic supports;

[0008] d. Lag step c and spray concrete on the tunnel wall surface for the first time. The first-time sprayed concrete can cover the steel arch frames, pipe-roof pipes and floor steel frames. After laying the waterproof board, carry out the secondary lining construction.

[0009] Preferably, in step a, after the construction of the pipe-roof pipes, pour concrete into the pipe-roof pipes.

[0010] Preferably, in step a, the pipe-roof pipes are located at the middle position of each inclined rock strata layer.

[0011] Preferably, in step b, construct one ring of support for each step, and it is located at the middle position of the trend of this step.

[0012] Preferably, the excavation step distances of step b and step c are the same, both being 1.0 - 1.5 m.

[0013] Preferably, step c lags behind step b in construction by 10 - 15 m.

[0014] Preferably, in step c, the steel arch frames and floor steel frames on the relatively low side of the inclination of the tunnel and the steel arch frames and floor steel frames on the relatively high side of the inclination of the tunnel are located in the same section.

[0015] Preferably, in step c, the adjacent steel arch frames along the axis on the relatively low side of the inclination of the tunnel and the adjacent floor steel frames along the axis in the tunnel are respectively connected with connecting steel bars.

[0016] Preferably, in step d, step d lags behind step c by two step distances, which is 2.0 - 3.0 m.

[0017] The key technical means and beneficial effects of the present invention are as follows:

[0018] 1. The present invention aims at the pumped-storage power station tunnel constructed along the trend in the inclined rock strata. First, excavate the relatively high side of the inclination from bottom to top. Before excavation, use pipe-roof pipes to support the excavated inclined rock strata. With the supporting effects of steel arch frames, floor steel frames and hydraulic supports, it is possible to prevent the inclined rock strata from sliding into the already excavated tunnel area under the action of its own gravity, and effectively control the rock strata movement caused by rock strata bias pressure; excavating from bottom to top is conducive to the falling of the rock strata, and the unexcavated rock strata in the upper part will not collapse as a whole layer, and at the same time, it is convenient to support the hydraulic supports.

[0019] 2. The present invention excavates the relatively lower-inclination side from top to bottom, which is conducive to ensuring the stability of the rock formation on the relatively lower-inclination side. During excavation, the support of steel arch frames is carried out in a timely manner, and the construction of steel arch frames and floor steel frames in the excavated tunnel area after the excavation of each layer of rock formation is ensured, which is conducive to the timely closure of the steel arch frames and floor steel frames in the excavated tunnel area and the timely closure of the entire cross-section into a ring after excavation.

[0020] 3. Aiming at the problem that the relatively higher-inclination side of the inclined rock formation is prone to slide into the tunnel under the influence of bias pressure, the construction method proposed by the present invention can prevent the rock formation on the relatively higher-inclination side from sliding into the tunnel. The pipe shed pipes are only constructed on the relatively higher-inclination side, which can not only solve the problem but also save construction materials. The present invention is particularly applicable to the situation where the tunnel cross-section is small and the deformation amount of the inclined rock formation under the influence of bias pressure is relatively small. The construction of the present invention is simple and conducive to popularization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the expected construction position of the pumped-storage power station tunnel in the inclined rock formation of the present invention;

[0022] Figure 2 is the construction schematic diagram of step a of the pumped-storage power station tunnel in the inclined rock formation of the present invention;

[0023] Figure 3 is the construction schematic diagram of step b of the pumped-storage power station tunnel in the inclined rock formation of the present invention Figure 1 ;

[0024] Figure 4 is the construction schematic diagram of step b of the pumped-storage power station tunnel in the inclined rock formation of the present invention Figure 2 ;

[0025] Figure 5 is the construction schematic diagram of step c of the pumped-storage power station tunnel in the inclined rock formation of the present invention Figure 1 ;

[0026] Figure 6 is the construction schematic diagram of step c of the pumped-storage power station tunnel in the inclined rock formation of the present invention Figure 2 ;

[0027] Figure 7 is the construction schematic diagram of step d, i.e., the final construction schematic diagram of the pumped-storage power station tunnel in the inclined rock formation of the present invention.

[0028] In the figure, 1 - inclined rock formation; 2 - tunnel; 3 - pipe shed pipe; 4 - steel arch frame; 5 - hydraulic support; 6 - floor steel frame; 7 - excavated tunnel area; 8 - tunnel lining. DETAILED DESCRIPTION OF THE INVENTION

[0029] The following is a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

[0030] A safety construction method for a tunnel of a pumped-storage power station in an inclined rock stratum, as Figure 1 shown, the axis of the tunnel 2 of the pumped-storage power station is consistent with the strike of the inclined rock stratum 1, and the tunnel 2 is constructed symmetrically horizontally, including the following steps:

[0031] a. As Figure 2 shown, on the relatively high-side of the dip of the tunnel 2, a number of pipe shed pipes 3 are constructed at intervals along the designed contour line of the tunnel 2. The pipe shed pipes 3 are constructed along the strike of the inclined rock stratum 1, that is, along the axis of the tunnel 2, and one pipe shed pipe 3 is constructed at the middle position of each inclined rock stratum 1; after construction, concrete is poured into the pipe shed pipes 3 for reinforcement;

[0032] b. As Figures 3 - 4 shown, the relatively high-side of the dip of the tunnel 2 is gradually constructed along the strike, and the construction length of each step is 1.0 - 1.5 m; the construction content of each step includes: excavating the inclined rock stratum 1 layer by layer from bottom to top, and after excavating each inclined rock stratum 1, the pipe shed pipes 3 in the just-excavated inclined rock stratum 1 are supported by hydraulic props 5 in time; the side section of the exposed tunnel 2 is supported by steel arch frames 4 in time, and the bottom surface of the exposed tunnel 2 is supported by a bottom plate steel frame 6 in time; the steel arch frames 4 and the bottom plate steel frame 6 are connected circumferentially, and the steel arch frames 4 are connected to adjacent pipe shed pipes 3 circumferentially; a hydraulic support 5 is supported on the central symmetry line of the tunnel 2, that is, the hydraulic support 5 connects the center of the tunnel arch top and the center of the bottom surface, and the hydraulic support 5 supported on the central symmetry line of the tunnel 2 is closed in a loop with the steel arch frames 4, the bottom plate steel frame 6, and the pipe shed pipes 3; and preferably one ring for each step, located at the middle position of the strike of this step;

[0033] c. Lagging 10 - 15 m behind the relatively high-side of the dip of the tunnel 2, as Figures 5 - 6 shown, the relatively low-side of the dip of the tunnel 2 is gradually constructed along the strike, and the construction length of each step is 1.0 - 1.5 m, which is the same as the construction step distance in step b; the construction content of each step includes: in the relatively low-side of the dip of the tunnel 2, excavating the inclined rock stratum 1 layer by layer from top to bottom, and after excavating each inclined rock stratum 1, the side section of the exposed tunnel 2 is supported by steel arch frames 4 in time and connected to the steel arch frames 4 already constructed in the relatively high-side of the dip of the tunnel 2; the bottom surface of the exposed tunnel 2 is supported by a bottom plate steel frame 6 in time and connected to the steel arch frames 4 and the bottom plate steel frame 6 in the same ring that have been constructed; the steel arch frames 4 and the bottom plate steel frame 6 on the relatively low-side of the dip of the tunnel 2 and the steel arch frames 4 and the bottom plate steel frame 6 on the relatively high-side of the dip of the tunnel 2 are located in the same section and correspond to each other, so that the steel arch frames 4 and the bottom plate steel frame 6 in the corresponding excavation step are closed in a loop; correspondingly, preferably one ring for each step, located at the middle position of the strike of this step;

[0034] The adjacent steel arch frames 4 along the axis in the relatively lower half side of the tunnel 2 and the adjacent floor steel frames 6 along the axis in the tunnel are respectively connected by connecting steel bars, and the hydraulic support 5 is removed.

[0035] d. As Figure 7 shown, lagging a certain distance behind step c, such as two step distances, that is, 2.0 - 3.0 m, shotcrete the initial shotcrete on the tunnel wall surface. The initial shotcrete can cover the steel arch frame 4, the pipe roof pipe 3 and the floor steel frame 6. After laying the waterproof board, the secondary lining construction is carried out.

[0036] The present invention is directed to a pumped - storage power station tunnel 2 constructed along the strike in an inclined rock formation 1. First, excavate the relatively higher half side from bottom to top. Before excavation, use the pipe roof pipe 3 to support the excavated inclined rock formation 1. Part of the pipe roof pipe 3 is located in the unexcavated rock formation and part is located in the excavated tunnel area 7. With the supporting effects of the steel arch frame 4, the floor steel frame 6 and the hydraulic strut 5, it can prevent the inclined rock formation 1 from sliding into the excavated tunnel area 7 under the action of its own gravity, and effectively control the rock movement caused by the rock pressure bias. Excavating from bottom to top is conducive to the falling of the rock formation. The upper unexcavated rock formation is intact and will not collapse, and at the same time, it is convenient to support the hydraulic strut 5.

[0037] After that, the present invention excavates the relatively lower half side from top to bottom, which is conducive to ensuring the stability of the rock formation on the relatively lower half side. During excavation, timely support the steel arch frame 4, and ensure that the steel arch frame 4 and the floor steel frame 6 are constructed in the excavated tunnel area 7 in time after each layer of rock formation is excavated. This is conducive to the timely closure of the steel arch frame 4 and the floor steel frame 6 in the excavated tunnel area 7, and is conducive to the timely closure of the entire section into a ring after excavation.

[0038] The present invention aims at the problem that the relatively higher half side of the inclined rock formation is prone to slide into the tunnel under the influence of the bias pressure. The proposed construction method can prevent the rock formation in the relatively higher half side from sliding into the tunnel. Constructing the pipe roof pipe only on the relatively higher half side can solve the problem and save construction materials. The present invention is particularly suitable for the situation where the tunnel section is small and the deformation amount of the inclined rock formation under the influence of the bias pressure is relatively small. The construction of the present invention is simple and conducive to popularization.

[0039] Of course, the above description is only the preferred embodiment of the present invention. The present invention is not limited to listing the above - mentioned embodiments. It should be noted that all equivalent replacements and obvious deformation forms made by any person skilled in the art under the guidance of this specification fall within the substantial scope of this specification and should be protected by the present invention.

Claims

1. A safety construction method for a tunnel of a pumped-storage power station in an inclined rock stratum, wherein the tunnel of the pumped-storage power station is constructed along the strike of the inclined rock stratum, and is characterized in that, It includes the following steps: a. On the relatively higher side of the tunnel's inclination, construct several pipe-roof pipes at intervals along the designed contour line of the tunnel. The pipe-roof pipes are constructed along the strike of the inclined rock strata, and one pipe-roof pipe is constructed for each layer of inclined rock strata; b. Gradually construct the relatively higher side of the tunnel's inclination along the strike. The construction content of each step includes: excavating the inclined rock strata layer by layer from bottom to top, and immediately using hydraulic props to support the pipe-roof pipes in the just-excavated inclined rock strata after each layer of inclined rock strata is excavated; promptly support the exposed side section of the tunnel with steel arch frames, and promptly support the exposed bottom of the tunnel with floor steel frames; connect the steel arch frames and the floor steel frames circumferentially, and connect the adjacent pipe-roof pipes circumferentially with the steel arch frames. Support with hydraulic supports on the central symmetry line of the tunnel, and the hydraulic supports supported on the central symmetry line of the tunnel are closed in a loop with the steel arch frames, the floor steel frames, and the pipe-roof pipes; c. Lagging behind the relatively higher side of the tunnel's inclination, gradually construct the relatively lower side of the tunnel's inclination along the strike. The construction content of each step includes: on the relatively lower side of the tunnel's inclination, excavate the inclined rock strata layer by layer from top to bottom, and immediately support the exposed side section of the tunnel with steel arch frames and connect them with the steel arch frames already constructed on the relatively higher side of the tunnel's inclination after each layer of inclined rock strata is excavated; promptly support the exposed bottom of the tunnel with floor steel frames and connect them with the steel arch frames and floor steel frames in the same ring that have already been constructed; remove the hydraulic supports; d. Lagging behind step c, initially spray concrete on the tunnel wall surface. The initially sprayed concrete can cover the steel arch frames, the pipe-roof pipes, and the floor steel frames. After laying the waterproof board, carry out secondary lining construction.

2. The safety construction method of a tunnel in a pumped storage power station according to claim 1, wherein, In step a, after the pipe-roof pipes are constructed, pour concrete into the pipe-roof pipes.

3. A safety construction method for a tunnel of a pumped storage power station according to claim 1, characterized in that, In step a, the pipe-roof pipes are located at the middle position of each layer of inclined rock strata.

4. A method for safe construction of a tunnel in a pumped-storage power station according to claim 1, characterized in that, In step b, construct one ring of support for each step, and it is located at the middle position of the strike of this step.

5. A safety construction method for a tunnel of a pumped storage power station according to claim 1 or 4, characterized in that, The excavation step distances in steps b and c are the same, both being 1.0 - 1.5 m.

6. A tunneling safety construction method for a pumped storage power station according to claim 1, characterized in that, The construction in step c lags behind the construction in step b by 10 - 15 m.

7. A method for safe construction of a tunnel in a pumped storage power station according to claim 1, characterized in that, In step c, the steel arch frames and the floor steel frames on the relatively lower side of the tunnel's inclination and the steel arch frames and the floor steel frames on the relatively higher side of the tunnel's inclination are located in the same section.

8. A method for safe construction of a tunnel in a pumped-storage power station according to claim 1, characterized in that, In step c, the adjacent steel arch frames along the axis in the relatively lower side of the tunnel's inclination and the adjacent floor steel frames along the axis in the tunnel are respectively connected with connecting steel bars.

9. A safety construction method for a tunnel of a pumped storage power station according to claim 1, characterized in that, In step d, step d lags behind step c by two step distances, which is 2.0 - 3.0 m.

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