Underground cavern and construction method for underground cavern

Abstract

The invention relates to a construction method for large-scaled underground cavern with rich groundwater and poor surrounding rock geologic condition. The underground cavern and a construction method for the underground cavern comprises the following steps that the multi-purpose arrangement types and methods such as advanced water drainage, advanced reinforcing of surrounding rock of a main cavern, advanced exploration and advanced monitoring are conducted by utilizing underground corridors, specifically, the multiple layers of underground corridors are arranged on an arch crown and side walls of an underground main cavern; the underground corridors on the periphery of the arch crown and the side walls are constructed first before the main cavern is excavated; groundwater level on the periphery of the main cavern is reduced in advance by utilizing the constructed underground corridors; and meanwhile, pre-consolidation grouting, prestressed anchor cable drilling construction and pre-embedding of monitoring equipment are conducted on the arch crown of the main cavern by utilizing the corridors on the periphery of the side walls on a top layer. According to the arrangement types and methods, can not only influence of underground water on the surrounding rock of the cavern be effectively reduced, but also the surrounding rock can be reinforced by advanced grouting for the main cavern, construction time of the anchor cable is shortened, and timely supporting role of the anchor cable is exerted; and by advancing pre-embedding of the monitoring equipment, deformation monitoring data of the surrounding rock during excavation of the main cavern can be accurately collected and mastered to guide the design and construction, and safety and stability of the underground cavern during the constructing period and running period are powerfully guaranteed.

Description

technical field [0001] The invention belongs to the field of underground engineering, and relates to an underground cavern and an underground cavern construction method, in particular to a large underground cavern with abundant groundwater and poor geological conditions of surrounding rocks and a construction method thereof. Background technique [0002] At present, for the construction of underground caverns with rich groundwater and poor surrounding rock conditions, underground corridors are mainly arranged around the underground caverns for permanent drainage; in terms of support, prestressed anchors need to be arranged on the basis of anchor shotcrete support. cable to control the deformation of the surrounding rock in the cavern. In conventional practice, the layout of the underground corridor is only used for permanent drainage, and the construction of the underground corridor often lags behind the construction of the main cavern, without considering the advance reduct...

AI Technical Summary

Problems solved by technology

In conventional practice, the layout of the underground corridor is only used for permanent drainage, and the construction of the underground corridor often lags behind the construction of the main cavern, without considering the advance reduction of the groundwater level around the main cavern. During the construction period, the surrounding rock of the main cavern is often due to Affected by groundwater, it is prone to landslides and other phenomena; prestressed anchor cables mostly use end anchor cables, and the construction of anchor cables and the embedding of monitoring instruments often have to wait for the excavation of the main cavern before construction, so the timeliness of anchor cable support is poor , the data collected by the monitoring instrument lags behind and cannot truly reflect the deformation of the surrounding rock. Often the anchor cable support is not timely, resulting in excessive deformation and instability of the surrounding rock during the excavation of the main cavern. The burial of monitoring instruments is delayed, and the deformation of the surrounding rock in the cavern cannot be grasped in time, resulting in the inability to predict the stability of the surrounding rock in the cavern, and landslides occur, which affect the safety of the construction period and cause delays in the construction period

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