含软弱层岩质边坡的动力响应研究

含软弱层岩质边坡的动力响应研究已成为边坡工程稳定性分析中的一个重要问题。为研究软弱层的特性对岩质边坡动力响应的影响，提供动力荷载作用下边坡防灾减灾的指导依据，运用UDEC离散元软件模拟地震力作用下含软弱层岩质边坡的动力响应系统地分析软弱层的倾角、埋深、弹性模量、厚度、泊松比和剪切刚度等因素对地震波放大现象的影响，得出边坡坡顶放大系数的变化规律，即随着软弱层倾角的增大，放大系数呈现出增大→减小→再增大→再减小，并出现地震响应减弱的现象；放大系数随软弱层埋深和厚度的增加而增大，但随弹性模量、剪切刚度的增大而减小，随泊松比的增加几乎不变。结合非重复性试验二元方差分析评价理论，对所得的放大系数进行计算分析，得出软弱层的特性因素对边坡放大作用的影响强度为软弱层的倾角＞埋深＞弹性模量＞剪切刚度＞厚度＞泊松比。研究结果有助于进一步揭示地震作用下边坡的失稳机制, 对震区边坡灾害的防治有一定的指导意义。

Research on dynamic response of rock slope with weak layer

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.