Experimental investigation on creep behavior of clastic rock

¹ Hunan Provincial Key Laboratory of Key Technology on Hydropower Development, Zhongnan Engineering Corporation, Changsha 410014, China
² College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao, Shandong 266580, China

^* Corresponding author’s e-mail: zhangyu@upc.edu.cn

Abstract

Many deflected fault zones exist under the dam foundation Xiang-jiaba Hydropower Station in southwestern China. Clastic rock is the main medium with poor physical and mechanical properties. In or-der to study the creep properties of the clastic rock, triaxial compression creep experiments were carried out on a rock servo-controlling rheology testing machine. From the test results, it can be concluded that the clastic rock has obvious creep characteristics, and the time-dependent deformation is large. Based on the test results, the relationship between axial strain and time under different confining pressures is studied. The relationship between axial strain rates and deviatoric stress under different stress levels is also discussed in de-tail. Furthermore, the creep failure mechanism under different confining pressures is analyzed as well. Therefore, the creep law of the clastic rock specimen is gained. The relationship between the Burgers creep model and its parameters is obtained by fitting the creep curve with Burgers creep model. The result shows that Burgers model can accurately describe the creep properties of the clastic rock in Xiang-jiaba Hydro-power Project.