Abstract：The experiment on the elasticity resisting coefficient of rock mass is very difficult to be done，so it is conducted only in the pressure tunnel of oversize hydroelectric projects. Radial hydraulic pressure pillow testing is a kind of method to measure the rock mass elasticity resisting coefficient. It was adopted in projects such as Yingxiuwan，Qingjiang，Ertan，etc.，during the 1960¢s and 1970¢s and only the relative deformation in diameter direction is needed to be measured. It is adopted in Yantan Hydropower Station to research rock elasticity resisting coefficient by measuring radial deformation. The results reflect the superposition and anisotropy of deformation and indicate the relationship between the elasticity resisting coefficient and pressure coefficient. The test provides valuable data for the practical projects.
