含泥化夹层顺层和反倾岩质边坡动力响应差异性研究

Dynamic response differences between bedding and count-tilt rock slopes with siltized intercalation

设计并制作了两个同尺寸的含泥化夹层顺层和反倾岩质边坡,并进行了大型振动台试验,对含泥化夹层顺层和反倾岩质边坡的动力响应差异性进行了分析,研究结果表明:顺层边坡坡体内部加速度放大系数整体上小于反倾边坡;在坡体中上部(相对高度大于0.4),顺层边坡坡面加速度放大系数大于反倾边坡,在坡体下部(相对高度小于等于0.4),顺层边坡坡面加速度放大系数与反倾边坡近似相等;顺层边坡和反倾边坡坡面位移随输入地震动强度增大而大幅度增加,顺层边坡坡面位移大于反倾边坡,且随着输入地震波幅值的增加,顺层边坡和反倾边坡坡顶位移之间的差值增大;反倾边坡较顺层边坡具有更高的地震稳定性;顺层边坡破坏形式主要表现为坡体后缘的垂直张拉裂隙、岩层沿泥化夹层的顺层滑动以及坡顶岩块崩落,而反倾边坡的破坏形式主要表现为坡面水平向和垂直向裂隙交错、泥化夹层挤出以及坡顶被震碎。

Two models with the same dimension, bedding and count-tilt rock slopes with siltized intercalation are designed, and large-scale shaking table tests are performed to analyze the seismic response differences between bedding and count-tilt rock slopes with siltized intercalation. The research results show that the acceleration amplification coefficient in the bedding rock slope is smaller than that in the count-tilt rock slope. The acceleration amplification coefficient on slope face of the bedding rock slope is larger than that of the count-tilt rock slope at the middle and upper parts of slope, where the elevation height is not less than 0.4, while the acceleration amplification coefficient on slope face of the bedding rock slope is close to that of the count-tilt rock slope at the lower part of slope, where the elevation height is less than 0.4. The displacements on slope faces of both the bedding and count-tilt rock slopes increase with the increase of the amplitude of input seismic waves, but the displacement on slope face of bedding rock slope is larger than that of count-tilt rock slope, and the difference value between increases with the amplitude of input seismic waves. The seismic stability of the bedding rock slope is stronger than that of the count-tilt rock slope; the failure forms of bedding rock slope mainly include vertical tension crack at the back edge, bedding sliding at mud layer and caving rocks at slope top, while those of the count-tilt mainly include intersect of horizontal and vertical cracks, squeezed siltized intercalation and shattered slope top.