Abstract:Contraposing the sand grout-limestone’s cylinder specimen taking from a gravity dam engineering,the uniaxial compression test of limestone and the straight shear test of two phase stuff gumming face of sand grout-limestone are made by RMT-150 multifunctional rigidity servo testing machine.Via the tests,the elastic modulus,Poisson’s ratio of limestone and shearing strength,intensive parameters of two phase stuff gumming face are obtained. Thereby,the compress-shear rupture criterion is presented to estimate dam stability besed on the idea of stress intensity factor. The relationship among gumming face strength,specimen size and elastic modulus,and that expression between the shear modulus and elastic modulus of limestone are found,which can be valuable reference for practical engineering.