Research on initial stress field of Baihetan hydropower station

A planned Baihetan hydropower station on the lower reaches of the Jinsha River, located between the hydropower stations of Wudongde and Xiluodu, is the third biggest hydropower station following the Three Gorges project and the Xiluodu power station. The station will have an installation capacity of 10 million kW. Baihetan hydropower station uses underground powerhouse, of which height and span respectively are 78.5 m and 32 m. To guarantee stability of wall rock of underground cavern, it is necessary to know the magnitude and direction of initial in-situ stress field exactly. Based on geological structure analysis and field testing, it is found that the directions of initial in-situ stress fields of both banks of Baihetan hydropower station, which are influenced by factors, such as fluvial erosion and slope unloading deflect from NWW to NE partly. Numerical inverse method is used to inverse boundary conditions of study area, it has rationality and veracity by comparing with measuring values.