浑厚山体随高程增加由表及里地震动响应研究

为探究浑厚山体不同高程由表及里地震动响应规律，以冷竹关山体为例，采用离散元软件建立地形与风化介质组合模型，并从底部边界输入汶川地震波信号，研究该山体两侧边坡的内外动力响应规律。结果表明，随着高程的增加，靠大渡河一侧边坡坡体内与坡表的加速度放大系数均表现出先增大后减小的节律性变化，在近坡顶时增大较快并达到最大值；靠近瓦斯沟一侧边坡坡表受地形起伏的影响，加速度放大系数存在凸坡放大、凹坡减小的特征；相同高程，随边坡由表及里深度的增加，加速度放大系数表现为逐步减小，当距坡表150~200 m时放大曲线趋于平缓；随高程的增加，加速度放大系数由表及里的减小速度变缓，且放大曲线收敛平缓的深度增大；随岩体风化程度的增加，岩体介质波速降低，共振效应使得加速度响应增大，与此同时，斜坡地形与介质组合效应使得坡表峰值加速度放大系数在2.0附近。

Study on Ground Motion Response of Thick Mountain from Surface to Interior with Elevation Increase

To explore the response law of ground motion from surface to interior in different elevations of thick mountain, based on Lengzhuguan mountain, we establish a combination model of terrain and weathering medium using discrete element software. We input wenchuan seismic wave signals from the bottom boundary to reveal the internal and external dynamic response law of the slope on both sides of the mountain. The results show that, as elevation increases, the acceleration amplification coefficients in the body and surface of the side slope of Daduhe first increase, decrease, and then increase rapidly, reaching the maximum value near the top of the slope. The slope surface of Wasigou side is affected by topographic relief and the acceleration amplification coefficient of convex slope is enlarged and the concave slope is decreased. At different elevations, the acceleration amplification coefficient decreases gradually with the increase of slope depth from the surface to the interior, and the amplification curve tends to be gentle when it is 150-200 m away from the slope surface. As the elevation increases, the acceleration amplification coefficient decreases slowly from the outside to the inside, and the gentle convergence depth of the amplification curve increases. The wave velocity of rock mass medium decreases with the increase of rock mass differentiation and the resonance effect increases the acceleration response. Meanwhile, the combination effect of slope topography and medium makes the peak acceleration amplification coefficient of slope surface near 2.0.