Abstract: Researching on the dynamic response of the rock slopes with weak layer has become an important issue in slope stability analysis. In order to discuss the influences of dynamic response of rock slope by weak layer’s characteristics and provide the directions and guidance for slope disaster prevention and mitigation under the dynamic load, the distinct element models are built and dynamic response of rock slopes with weak layer under seismic force are simulated by the universal distict element code(UDEC). After simulating in different conditions: various dip angles, burial depths, elastic moduli, thicknesses, Poisson's ratios and shear stiffness factors of the weak layer, the amplitude values of slope crest and bottom are obtained and the amplification coefficients are calculated; through systematically analyze the amplification coefficients, the amplification law of slope crest which influenced by seismic wave is got, namely, with increasing of dip angle, the amplification coefficient demonstrates increase→decrease→reincrease→decrease law, and appears response weakening phenomenon at the decreased parts. Along with burial depth and thickness increasing of weak layer, the amplification become bigger, but it decreases with elastic modulus and the shear stiffness increasing; the amplification almost doesn’t change with increasing of Poisson's ratio. Combining with the non-repetitive test binary analysis of variance evaluation theory, the obtained slope amplification coefficients are analyzed; and then, it is obtained that the significant factors which contribute to the slope dynamic response from great to small are the dip angle, burial depth, elastic modulus, shear stiffness, thickness, Poisson's ratio of the weak layer. The results are helpful to further researches on the slope instability mechanism under earthquake, and can provide the significante guidance to slope disaster prevention in earthquake region.

Key words: universal distinct element code, rock slope, dynamic response, weak layer, amplification coefficient