Underground cavern excavation support system and construction method

Abstract

An underground cavern excavation support system includes a top arch excavation area, an end wall excavation area and an inverted arch excavation area which are sequentially connected from top to bottom. The top arch excavation area is provided with a finalized operation platform, and anchor rods are arranged outside the top arch excavation area and the end wall excavation area. The top arch excavation area is also provided with a drainage body. Two symmetrically arranged water and electricity prefabricated boxes are arranged in the inverted arch excavation area. Each water and electricity prefabricated box is provided with a hydroelectric isolation panel dividing the water and electricity prefabricated box into an upper part and a lower part, wherein the upper part of the water and electricity prefabricated box is provided with an electric line pipe gallery, and the lower part of the water and electricity prefabricated box is provided with an underground drainage pipe gallery. Comparedwith the prior art, excavation area blocks on two sides form an obtuse angle, which is beneficial to the geometric stability during the whole excavation process. Support conducted after complete excavation of the whole block is not required, the periphery is excavated and supported first, and then the middle area is excavated. The excavation and support construction efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of underground cavern excavation, in particular to an underground cavern excavation support system and a construction method. Background technique [0002] At present, most of the excavation construction of underground caverns adopts the method of excavating the pilot tunnel in the middle first, and then excavating the expansion areas on both sides. The support work is in the entire excavation area behind the expansion area. For support work, the general construction sequence is generally: excavate the pilot tunnel in the middle of the top arch area to a certain depth first → excavate after the expansion area on both sides of the top arch area → excavate behind the face of the top arch expansion area Carry out arch support in the entire top arch area → Excavate the pilot tunnel in the middle of the end wall area of ​​the lower floor to a certain depth → Excavate after the expanded excavation area on both sid...

AI Technical Summary

Problems solved by technology

This method makes the rock strata in the middle pilot tunnel exposed for too long, resulting in excessive stress release and deformation, which is likely to cause engineering accidents

In addition, the drainage operation of this kind of excavation construction system is often too rough, and the drainage system often lags behind the excavation support. If it encounters excessive water volume or excessive water head, it is easy to cause engineering accidents

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