A discussion on estimating dynamic mechanical parameters of rocks#br#
considering earthquake actions
CUI Zhen1，2，SHENG Qian1，2，CHEN Pingzhi3，4，LENG Xianlun1，2，ZHU Zeqi1，2，CHEN Liujie5
(1. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；2. University of Chinese Academy of Sciences，Beijing 100049，China，3. PowerChina Huadong Engineering Corporation limited，Hangzhou，Zhejiang 311122，China；4. HydroChina Itasca Research and Development Center，Hangzhou，Zhejiang 310014，China；5. School of Civil Engineering，Guangzhou University，Guangzhou，
Guangdong 510006，China)
Abstract：Dynamic mechanical parameters of rock mass under earthquake actions are the basis for accurate seismic stability analysis of rock engineering. In the present study，on the basis of exploring the reasonable strain rate of rock materials under earthquake actions，tests and empirical formulas were utilized to investigate the problem of determining the mechanical parameters for igneous rocks considering seismic effect. The results show that，for the relying projects，the corresponding representative strain rate is in the range of 10－2 to 5×10－2/s which is between the quasi-static rate and traditional “medium strain rate”. Fitting analysis of dynamic test results reveals that the intercept of the strength envelope changes with the strain ratio while the shape of the envelope keeps changeless. Consequently，empirical formulas for evaluating dynamic strength parameters were proposed using static parameters and the strain ratio，and a estimating method of rock dynamic modulus under seismic actions was presented based on Hoek & Diederichs equation. The Baihetan hydropower plant project was taken as a study case to illustrate the proposed approach.
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2019, Vol. 38 
