A Quantitative Evaluation Method for Cavitation Conditions of Large-Scale Underground Cavities in Shallow Buried Hard Rock

Abstract

The invention discloses a quantitative evaluation method for a cavitation condition of a large-size underground cavity of a shallow buried hard rock. According to the quantitative evaluation method, the rock type of an engineering region is distinguished to be hard rock and large-span and shallow buried underground cavity, the integral safety coefficient of upper coated rock on roof of the underground cavity, surrounding rock disturbance intensity stress ratio DSSR and a safety coefficient of a large-size key block exceeding 10,000 m<3> of the underground cavity are used as main quantitative evaluation indexes, a moving direction of a long and large structural surface shall intersect with an axis of a main cavity at a large angle, the surrounding rock disturbance intensity stress ratio after evacuation of the underground cavity is obtained by calculation of a numerical value method, an included angle between maximum horizontal main stress direction and an axial direction of the main cavity is quantized, the integral stability of the upper coated rock between the underground cavity roof and a ground surface is quantized by a strength reduction method, and the stability of the large-size key block exceeding 10,000 m<3> of the underground cavity is quantized by a block theory. Compared with a traditional method, the quantitative evaluation method has the advantages of more science, completeness and index clearness and is easy to implement, the construction risk can be reduced, and the integral stability of an underground cavity group is improved.

Description

technical field [0001] The present invention relates to the technical field of analysis methods for cave-forming conditions of underground caverns, in particular to a quantitative evaluation method for cave-forming conditions of shallow-buried hard rock large-scale underground caverns, which is suitable for shallow-buried large-span underground caverns mainly composed of hard and brittle rocks Surrounding rock stability analysis provides an effective quantitative evaluation method, so that quantitative judgment data of underground cavern formation conditions can be obtained, which is conducive to the stability of underground cavern surrounding rock and ensures construction safety. Background technique [0002] With the rapid development of my country's society and economy, large-span underground projects such as underground hydropower stations, underground oil depots, underground hangars, and underground venues have been widely used in many fields such as hydropower, energy, ...

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Problems solved by technology

[0004] At present, the relevant regulations and engineering experience generally only consider the influence of factors such as the magnitude and orientation of the ground stress and the occurrence of the structural surface on the cavern formation conditions of the underground cavern. How to determine the thickness of the overlying rock mass and the Factors that have a great influence on the formation of caves, such as its safety, the spatial distribution of the in-situ stress field in the engineering area, and the safety of key blocks in underground caverns, have not been considered.

Commonly used evaluation methods such as classification of surrounding rocks, engineering analogy, reference codes, and geomechanical model tests are mostly qualitative in the evaluation of the formation conditions of large-scale underground caverns in shallow hard rock, and most of them are single methods or single indicators in the evaluation of formation conditions. The application of cave condition evaluation is lack of comprehensiveness and representativeness

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