PREDICTION OF INITIATION STRESS OF DILATION OF BRITTLE
ROCKS
WANG Yu1，2，LI Xiao1，BEN Yuxing1，WU Yanfang1，ZHANG Bo1，2
(1. Key Laboratory of Engineering Geomechanics，Institute of Geology and Geophysics，Chinese Academy of Sciences，Beijing 100029，China；2. Graduate University of Chinese Academy of Sciences，Beijing 100049，China)
Abstract：The Servo-controlled triaxial rock testing system TAW–2000 was used to obtain the characteristic mechanical parameters of 32 group of rock samples of granite and diorite. The relationships of the initiation stress of dilation(crack damage stress) with the elastic modulus，Poisson?s ratio and the porosity were established resulting in a simplified model for crack damage stress. The elastic modulus is a measure of overall rock stiffness including the stiffness of grain to grain contacts and the intergranular matrix. The porosity is a measure of void space in the rock consisting primary of fissures，pores and open cracks. They are both closely related to the initiation stress of rock dilation. The initiation stress of dilation is correlated positively with the elastic modulus，and negatively with the porosity. A mathematical model for the initiation stress of dilation was obtained through data fitting the test results. The model can be used to calculate the initiation stress of dilation once the elastic modulus，the porosity and Poisson's ratio are known.
2014, Vol. 33 
