ANISOTROPY OF SLATE STRENGTH IN WEST ROUTE OF SOUTH-TO-NORTH WATER TRANSFER PROJECT

Sandstone and slate are the main rock types in the west route area of the South-to-North Water Transfer Project.The strength of slates is anisotropic obviously.It plays a significant role in the choice of the diversion dam site and the design and construction of the deep and long tunnelsThis paper studies the strength characters and deformation law of slates,and confirms the reasonable strength parameters of slates.The uniaxial compression deformation tests and triaxial compression tests are carried out on slate samples drilled in the west route area.The study considers the various laws of the slate strength with the dips of bedding planes.The anisotropy of the slate strength is obtained with the Hoek-Brown criterion and based on these test results.The shear strength of the rock mass is confirmed and becomes the foundation for engineering design.