地震作用下含软弱夹层的顺倾岩质边坡加速度放大效应探究

Acceleration Amplification Effects of Bedding Rock Slope with Weak Interlayer Under Earthquake

基于FLAC3D数值软件,建立含软弱夹层的顺倾岩质边坡模型,合理考虑地震波输入方式、模型边界条件、网格尺寸和力学阻尼,探究地震作用下含软弱夹层的顺倾岩质边坡加速度放大效应和软弱夹层区域加速度放大系数的变化规律,探究和分析软弱夹层的负效应。研究结果表明:在软弱夹层区域,加速度放大系数增加的速度更快;软弱夹层厚度越厚,软弱夹层位置越低,放大效应越明显;当软弱夹层倾角相差不大时,软弱夹层位置变化不大,此时软弱夹层倾角变化对加速度放大效应的影响较软弱夹层位置变化更为显著,即软弱夹层倾角越大,放大效应越明显;当软弱夹层倾角相差较大时,软弱夹层位置变化也较大,此时软弱夹层位置变化的影响更为显著,即软弱夹层位置越低,放大效应越明显。

Based on the reasonable selection of seismic input, boundary conditions of model, mesh size and mechanic damping, a FLAC3 D numerical model was established to investigate the acceleration amplification effect of the bedding rock slope with weak interlayer. The negative effect of weak interlayer was analyzed through the law of variation of acceleration amplification coefficient in the weak interlayer region. The results show that: In the weak interlayer region, the acceleration amplification coefficient increases faster;The thicker the weak interlayer is, the lower the position of the weak interlayer is, the more significant the seismic amplification effect is;When the dip angle difference of the weak interlayer is not particularly large, the position of the weak interlayer does not change much. In this situation, the influence of the dip angle change of the weak interlayer on the acceleration amplification effect is more significant than the position change of the weak interlayer, that is, the larger the dip angle of the weak interlayer is, the more obvious the seismic amplification effect is;When the dip angle difference of the weak interlayer is large, the position of the weak interlayer changes greatly. In this condition, the influence of the position change of the weak interlayer is more significant, which means the lower the position of the weak interlayer is, the more obvious the seismic amplification effect is.