Analysis of stress field characteristics of a certain pumped storage power station based on hydraulic fracturing test

Stress field is a very important load in underground engineering construction. It is an important index to understand the deformation mechanism of surrounding rock and determine the construction scheme. In order to reveal the stress field distribution characteristics of the pumped storage power station, the in-situ stress test was carried out with hydraulic fracturing method. The results show that the maximum stress value of the rock mass at the test position is 24.9 MPa, and the corresponding hole depth is 427.8 m; The lateral pressure coefficient in the direction of maximum horizontal principal stress at each measuring point ranges from 1.2 to 2.2, with an average of 1.6; The lateral pressure coefficient in the direction of the minimum horizontal principal stress ranges from 0.8 to 1.4, with an average of 1.0. The in-situ stress at the measured position presents a tendency of σ_H>σ_h≥σ_Z, the in situ stress field is dominated by horizontal stress, and the direction is about NNW to NW. The measured results of in-situ stress are basically consistent with the direction of regional stress field. The in-situ stress test data provide a basis for the engineering design of the pumped storage power station and support for enriching the in-situ stress database in South China.