Regression analysis of initial geostress field in dam zone of Dagangshan hydropower station

In view of the influence of completely and intensively weathered stratum in the shallow surface of slope and fault fracture belt on the initial geostress field in dam zone of Dagangshan hydropower station, the 3D initial geostress regression analysis model is established based on the measured geostress data and geologic structure as well as topography features of V-shaped river valley. The optimal geostress regression coefficients have been achieved through 3D multivariate regression numerical analysis and the initial geostress field in dam zone of Dagangshan hydropower station is exactly simulated. The calculation results show that the initial geostress field in dam zone is a medium to high stress field composed of tectonic stress and dead-weight stress. The tectonic stress is prominent at shallow level and the dead-weight stress is prominent at deep level, which provides important reference basis for excavating simulation and long-term stability analysis of slope.