Dynamic response characteristics and instability criteria of steep bedding rock slopes
摘要
A model of a steep bedding rock slope is designed and produced, and large-scale shaking table tests are conducted to analyze the dynamic response and deformation failure mode of the steep bedding rock slope under earthquake action. The results show that the natural vibration frequency of the steep bedding rock slope model decreases gradually with increasing vibration number and that the damping ratio increases gradually with increasing vibration frequency. The horizontal acceleration amplification coefficient of the model slope shows an obvious elevation amplification effect and surface trend effect. There are obvious differences in the slope acceleration response under the action of different types of input seismic waves. The acoustic emission parameters increase nonlinearly with increasing input seismic wave amplitude, and the acoustic emission characteristics during the failure process of the steep bedding rock slope can be divided into two stages: a slow rise period and a sharp rise period. The deformation evolution process of the steep bedding rock slope under the action of seismic dynamics can be divided into three stages: the formation of a tensile crack; the downward expansion of the tensile crack; and the sudden shear of the locked segment and the sudden instability of the slope. According to the abrupt cusp catastrophe theory, a correlation instability criterion is established based on the test results; the critical acceleration amplitude of the slope dynamic instability is quantitatively determined to be 0.4 g.