A construction method for excavating an underground powerhouse

Abstract

This invention provides a construction method for excavating an underground powerhouse, comprising: Step S1: constructing a ventilation and safety tunnel, an access tunnel, and a tailrace branch tunnel for the underground powerhouse; characterized by further comprising the following steps: Step S2: dividing the underground powerhouse to be excavated into an upper construction area, a first reserved area, and a lower construction area from top to bottom; the lower construction area is further divided into a second reserved area and a lower excavation area from left to right; Step S3: excavating the upper construction area using the ventilation and safety tunnel and the access tunnel, and excavating the lower excavation area using the tailrace branch tunnel; Step S4: excavating the first and second reserved areas using the access tunnel and the tailrace branch tunnel. This invention's construction method for excavating an underground powerhouse improves the excavation speed and resource utilization rate of the underground powerhouse.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower construction technology, and in particular to a construction method for excavating underground powerhouses. Background Technology

[0002] Underground powerhouse structures are commonly used in hydroelectric power projects and pumped storage power stations. The construction of the underground powerhouse is a critical path in the overall main project construction, and the excavation of the underground powerhouse is one of the restrictive and controlling aspects of the project construction, with the excavation period directly affecting the project's power generation target. Traditional underground powerhouse excavation adopts a top-down, layer-by-layer excavation procedure, with each layer's excavation occupying a significant portion of the linear construction period, resulting in a long construction cycle and low resource utilization. Summary of the Invention

[0003] The purpose of this invention is to provide a construction method for excavating underground powerhouses, so as to improve the excavation speed and resource utilization rate of underground powerhouse construction.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a construction method for excavating an underground powerhouse, the construction method comprising:

[0005] Step S1: Construction of the underground powerhouse ventilation and safety tunnel, access tunnel, and tailrace branch tunnel; its structural features include the following steps:

[0006] Step S2: Divide the underground powerhouse to be excavated into an upper construction area, a first reserved area, and a lower construction area from top to bottom; the lower construction area is further divided into a second reserved area and a lower excavation area from left to right;

[0007] Step S3: Excavate the upper construction area using the ventilation and safety tunnel and the access tunnel to the plant, and excavate the lower excavation area using the tailrace branch tunnel;

[0008] Step S4: Excavate the first and second reserved areas using the access tunnel and tailrace branch tunnel.

[0009] The aforementioned construction method for excavating an underground powerhouse first divides the underground powerhouse into an upper construction zone, a first reserved zone, and a lower construction zone before excavation. During excavation, the upper construction zone is excavated using a ventilation / safety tunnel and an access tunnel, while the lower excavation zone is excavated using a tailrace tunnel. Finally, the first and second reserved zones are excavated using the access tunnel and tailrace tunnel. Compared to the traditional top-down layered excavation method for underground powerhouses, this method optimizes the straight-line time of all excavation layers in conventional excavation methods, reducing the overall excavation time, and also offers advantages such as faster construction speed and higher resource utilization.

[0010] Furthermore, in step S3, both the upper construction area and the lower excavation area are constructed using layered excavation.

[0011] Furthermore, the upper construction area is divided into a top arch layer and a rock anchor beam layer from top to bottom. The top arch layer is constructed using a ventilation and safety tunnel, while the rock anchor beam layer is constructed using a ventilation and safety tunnel and an access tunnel to the plant.

[0012] Furthermore, in step S3, after the upper construction area and the lower excavation area are both completed, a slag chute is vertically excavated in the middle of the first reserved area.

[0013] Furthermore, the cross-sectional shape of the slag chute is circular.

[0014] Furthermore, the cross-sectional width of the slag chute is 2m to 2.4m.

[0015] Furthermore, in step S4, the first reserved area is constructed by layered excavation. When the bottom layer of the first reserved area is excavated, a blasting cushion layer is laid on the bottom surface of the lower excavation area.

[0016] Furthermore, the blasting cushion layer is constructed from the excavated material above the first reserved area.

[0017] Furthermore, the first reserved area is divided into two layers from top to bottom for excavation construction.

[0018] Furthermore, the height of the first reserved area is 10m to 15m.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] (i) The construction method for excavating an underground powerhouse according to the present invention has the advantages of fast excavation speed and high resource utilization rate.

[0021] (II) This invention solves the shortcomings of existing traditional construction technology, such as long construction cycle and low resource utilization rate. It provides a construction method with fast construction progress, high resource utilization rate, and simultaneous excavation of underground powerhouses from top to bottom. It is especially suitable for underground powerhouse excavation projects with special requirements for construction period and good geological conditions. It provides a new reference for future underground powerhouse excavation construction methods and has significant social benefits. Attached Figure Description

[0022] Figure 1 This is a schematic flowchart of the method of the present invention;

[0023] Figure 2 This is a schematic diagram of the longitudinal section of an underground powerhouse excavated using the method of the present invention.

[0024] In the diagram: 1. Tailwater tunnel; 2. Water diversion tunnel; 3. Busbar tunnel; 4. Upper construction area; 5. First reserved area; 6. Lower construction area; 61. Second reserved area; 62. Lower excavation area; 7. Slag chute; L. Excavation layer line. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" used below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0026] like Figures 1-2 As shown, a construction method for excavating an underground powerhouse according to this embodiment includes the following steps:

[0027] Step S1: Construct the underground plant ventilation and safety tunnel, the access tunnel, and tailrace branch tunnel 1.

[0028] Step S2: Divide the underground powerhouse to be excavated into an upper construction zone 4, a first reserved zone 5, and a lower construction zone 6 from top to bottom; the lower construction zone 6 is further divided into a second reserved zone 61 and a lower excavation zone 62 from left to right. The second reserved zone 61 can reduce the disturbance to the sidewalls caused by the large-scale excavation in the lower construction zone and provide auxiliary support for the first reserved zone 5.

[0029] Step S3: Excavate the upper construction zone 4 using the ventilation and safety tunnel and the access tunnel to the plant, and excavate the lower excavation zone 62 using the tailrace branch tunnel 1.

[0030] Step S4: Excavate the first reserved area 5 and the second reserved area 61 using the access tunnel and tailrace branch tunnel 1.

[0031] The construction method for excavating an underground powerhouse according to this embodiment is applicable to situations where the surrounding rock geological conditions are good (Class II to III), there are no other adverse geological conditions, and the bearing capacity of the surrounding rock meets the construction requirements. The upper and lower construction spaces utilize independent passages for slag removal and ventilation.

[0032] In step S3 of the method in this embodiment, both the upper construction zone 4 and the lower excavation zone 62 are constructed using layered excavation.

[0033] In this embodiment, the upper construction area 4 is divided into a top arch layer and a rock anchor beam layer from top to bottom. The top arch layer is constructed using a ventilation and safety tunnel, while the rock anchor beam layer is constructed using a ventilation and safety tunnel and an access tunnel to the plant.

[0034] In step S3 of this embodiment, after the upper construction area 4 and the lower excavation area 62 are both completed, a chute 7 is vertically excavated in the middle of the first reserved area 5. The chute 7 has a circular cross-sectional shape. The cross-sectional width of the chute 7 is 2m to 2.4m.

[0035] In step S4 of this embodiment, the first reserved area 5 is constructed by layered excavation. When the bottom layer of the first reserved area 5 is excavated, a blasting cushion layer is laid on the bottom surface of the lower excavation area 62. The blasting cushion layer is constructed from the excavation residue of the upper part of the first reserved area.

[0036] In this embodiment, the first reserved area 5 is excavated in two layers from top to bottom. The height of the first reserved area 5 is 10m to 15m.

[0037] The construction method for excavating underground powerhouses in this embodiment has the advantages of fast excavation speed and high resource utilization. This construction method is particularly suitable for underground powerhouse excavation projects with special requirements for construction period and good geological conditions. It provides a new reference for future construction methods of underground powerhouses and has significant social benefits.

[0038] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present embodiments by those skilled in the art will fall within the scope defined by the appended claims.

Claims

1. A construction method for excavating an underground powerhouse, the construction method comprising: Step S1: Construction of the underground plant ventilation and safety tunnel, the access tunnel, and the tailrace branch tunnel (1); characterized in that it also includes the following steps: Step S2: Divide the underground plant to be excavated into an upper construction area (4), a first reserved area (5) and a lower construction area (6) from top to bottom; the lower construction area (6) is divided into a second reserved area (61) and a lower excavation area (62) from left to right. Step S3: Excavate the upper construction area (4) using the ventilation and safety tunnel and the access tunnel to the plant, and excavate the lower excavation area (62) using the tailwater branch tunnel (1); Step S4: Excavate the first reserved area (5) and the second reserved area (61) using the access tunnel and tailrace branch tunnel (1); the first reserved area (5) is divided into two layers from top to bottom for excavation construction. When the bottom layer of the first reserved area (5) is excavated, a blasting cushion layer is laid on the bottom surface of the lower excavation area (62). The blasting cushion layer is laid by the excavation residue of the upper part of the first reserved area.

2. The construction method for excavating an underground powerhouse according to claim 1, characterized in that, In step S3, both the upper construction area (4) and the lower excavation area (62) are constructed using layered excavation.

3. The construction method for excavating an underground powerhouse according to claim 2, characterized in that, The upper construction area (4) is divided into a top arch layer and a rock anchor beam layer from top to bottom. The top arch layer is constructed using a ventilation and safety tunnel, while the rock anchor beam layer is constructed using a ventilation and safety tunnel and an access tunnel to the plant.

4. The construction method for excavating an underground powerhouse according to claim 1, characterized in that, In step S3, after the upper construction area (4) and the lower excavation area (62) are completed, a slag chute (7) is vertically excavated in the middle of the first reserved area (5).

5. The construction method for excavating an underground powerhouse according to claim 4, characterized in that, The cross-sectional shape of the slag chute (7) is circular.

6. The construction method for excavating an underground powerhouse according to claim 4, characterized in that, The cross-sectional width of the slag chute (7) is 2m to 2.4m.

7. A construction method for excavating an underground powerhouse according to any one of claims 1-6, characterized in that, The height of the first reserved area (5) is 10m~15m.

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