含泥化夹层反倾岩质边坡动力响应的大型振动台试验

Large-scale Shaking-table Test to Study Dynamic Responses of Anti-inclined Rock Slopes Interlayered with Silt

摘要:

针对含泥化夹层反倾岩质边坡制作相似比为1:30的试验模型进行大型振动台试验, 研究泥化夹层饱水前和饱水状态下边坡的加速度和位移响应规律, 探讨边坡的破坏模式。试验结果表明:泥化夹层饱水后坡面水平向加速度放大系数小于饱水前;泥化夹层饱水前和饱水后随着相对高度的增加, 坡面水平向加速度放大系数呈现非线性增加的趋势, 其整体上大于坡体内部的加速度放大系数;坡面位移从下至上在泥化夹层饱水前, 呈现出非线性增长特性;饱水后位移呈先增大后减小, 临近坡肩处坡面最大, 坡面呈现鼓出形态。泥化夹层饱水前, 在幅值为0.3 g的地震波作用下坡体仅出现坡肩局部掉块;饱水后, 输入地震动幅值≥0.4 g时, 坡体先出现坡肩的局部掉块, 随后坡体沿中上部的饱和泥化夹层滑动剪出, 与此同时, 坡体中上部出现纵向裂隙并与水平裂隙贯通, 坡顶被震碎。

Abstract:

A 1:30 scale model of an anti-inclined rock slope interlayered with silt was constructed,and a large-scale shaking-table test was performed to study the dynamic responses (acceleration and displacement) when the moisture content of silt layers change.The results are as follows:the horizontal amplification coefficients on the slope face after the silt layers became saturated were less than those before saturation;the coefficients increased with slope height in a nonlinear fashion;the coefficients on the slope face were larger than those in the slope body;before saturation,the displacement of the slope face increased in a nonlinear fashion with an increase in height;the displacement of the upper slope face (relative height between 0.6 and 0.9) was larger than those in other sections;after saturation,the displacement first increased and then decreased with increasing height,maximum displacement occurred near the top of the slope;and the slope displayed a bulging shape.Before saturation,slope failure occurs when the amplitude of the seismic wave is 0.3 g.After saturation,when the amplitude is no less than 0.4 g,first,slope failure occurs at the shoulder,then the slope slides and shears out from the upper levels,and simultaneously,longitudinal cracks appear and intersect with the horizontal fractures.The top of slope is left shattered.