Rock mass deformation modulus estimation models based on in situ tests

It is valuable to build an empirical model to estimate rock mass deformation modulus which is difficult to be determined by in situ tests. Based on 84 data sets from Yalong River Jinping-I hydropower station, the correlation between some easily measured geotechnical parameters and rock mass deformation modulus is analyzed. A two-parameter estimation model with higher estimation capacity than previous models is established based on a nonlinear regression algorithm. The P-wave acoustic velocity (Vp) and Q-value of rock mass are included in this two-parameter estimation model. Besides, according to the obtained data, it is not suitable to use an empirical model including elastic modulus of intact rock (Ei) to estimate rock mass modulus under high crustal stress condition.