【摘要】 运用有限差分软件FLAC3D,建立了某一含软弱夹层的顺层岩质边坡三维模型,首先对其在地震作用下的响应规律进行了研究,然后通过塑性区、位移时程,以及关键单元剪应变增量的变化分析了其变形机制。计算表明:地震作用下顺层岩质边坡坡面点水平向和垂向加速度峰值放大系数随高程增加均呈增大趋势,在结构面及坡顶处增幅较大;边坡顶点水平向和垂向加速度峰值放大系数自坡内向坡面方向呈增大趋势,在结构面处增幅较大;岩体对输入地震波存在垂直放大效应,其滤波作用没有土质边坡明显;顺层岩质边坡变形破坏主要受软弱夹层控制,表现为软弱结构面上部拉破坏与下部剪切破坏;给出了顺层岩质边坡滑移面位置的确定方法以及边坡失稳判定方法。研究结果对顺层岩质边坡动力作用下稳定性分析及抗震设计具有一定指导意义。更多还原

【Abstract】 Seismic slope dynamic response and the deformation mechanism are the premises of analyzing the dynamic stability of slopes.The response regulation of a bedding rock slope under the seismic action is discussed by using the three-dimensional finite difference software FLAC3D.The deformation mechanism is analyzed through the plastic zone,displacement time-histories as well as changes of shear strain increment of key elements.The calculation shows that,under the seismic action,the amplification coefficients of the horizontal and vertical peak accelerations of the bedding rock slopes increase with the increasing elevation and come to the maximum at the structural plane and the top of the slope;those at the top of the slope increase with the decrease of the distance from the slope surface and come to the maximum at the structural plane;the rock mass has vertical amplification effect on the input seismic waves and its filtering effect is inferior to the soil slope;the deformation damage of rock slopes mainly comes from the weak structural plane,formed by upper tension failure and bottom shear failure;the research also gives the methods of determining the position of the sliding surface of bedding rock slope’s and the judgment of slope instability.The results of the research have certain significance to analyzing the stability of bedding rock slopes and seismic design.更多还原