Soft rock wall of tunnels in deep mining will have large creep deformation under the high stress ,lower confinement pressure and disturbance conditions. Most of the creep deformation is caused by disturbing load. Hence, study on the creep property of rock under disturbing load and exploring creep and failure mechanism of soft rock is of great significant for soft rock support in deep mining. In this paper, triaxial compression step-wise loading creep experiments of soft grey green mudstone and oil shale specimens were carried out on the rock creep disturbance test machine. Based on the triaxial creep experimental results of soft rock, the variance of axial and lateral strains of soft rock under different confining pressures was investigated, and it is important for the identification of parameters in the soft rock engineering. Then the relationship between axial creep deformation and lateral creep deformation of rock was investigated. The effect of low confining pressure and gravity impact disturbance on the axial and lateral deformation properties was analyzed primarily.At the same time, the plastic deformation property of rock in the process of triaxial creep was also analyzed. The effect of creep stress level on the lateral-axial deformation property of soft rock was discussed. At last, microscopic characteristics of creep failure of rock under low confining pressures were analyzed.
FU Zhi-liang GAO Yan-fa CUI Xi-hai FAN Qing-zhong YANG Yong-jie WANG Su-hua
Department of Water Resources & Hydropower Engineering Shandong University of Science & technology, Geotechnical mechanics Research Center, China University of Mining &Technology,Beijing 100083,China School of Resources Development &Managment Engineering ,Anhui University of Science &Technology , Hu Department of Mechanics ,College of Hydraulic and Civil Engineering,Shandong Agricultural University Department of Water Resources & Hydropower Engineering Shandong University of Science & technology,