Abstract: The accelerated construction of pumped storage power stations underscores the importance of reasonable arrangement in-situ stress testing and precise data acquisition for high-head pumped storage power stations. This study, taking a high-head pumped storage power station as an example, conducted comprehensive in-situ stress measurements across various survey stages, considering the topographic and in-situ stress characteristics. By integrating in-situ stress field inversion, we obtained the spatial three-dimensional in-situ stress field distribution and analyzed the anti-splitting properties of the surrounding rock. The comprehensive measurements revealed that the two-dimensional surface deep hole results vary with the buried depth gradient, exhibiting stress concentration in the middle and shallow regions, aligning with the in-situ stress distribution patterns of high-head pumped storage power stations. The maximum measured principal stress in the underground plant and high-pressure bifurcation pipe reached 20.9 MPa, while the minimum principal stress was 7.0 MPa, indicating that horizontal stress is the dominant stress in the rock mass. The maximum principal stress direction is concentrated towards the NEE orientation. The inversion of the initial in-situ stress field can be carried out by using the comprehensive measured results to strengthen the refinement of the model, which can better reflect the characteristics of the in-situ stress field of such projects, and is conducive to the anti-splitting analysis of the surrounding rock and the selection of subsequent lining schemes. This study demonstrates the feasibility of comprehensive in-situ stress testing for high-head pumped storage projects, providing a valuable reference for in-situ stress investigations in such power station projects.

Key words: comprehensive in-situ stress test, in-situ stress field inversion, anti-cracking analysis