黄土斜坡坡面位移和加速度响应特性的振动台试验研究

以平凉崆峒区黄土塬斜坡为原型，开展含裂隙黄土斜坡和不含裂隙黄土斜坡的对比振动台模型试验，研究地震荷载作用下黄土斜坡坡面位移和加速度响应规律。通过三维光学测量分析系统，高精度、实时获得斜坡表面的变形量。试验表明：随着输入地震荷载的增加，含裂隙黄土斜坡和不含裂隙黄土斜坡坡面PGD均呈现出随着坡高的增加逐渐增大的变化趋势；在相同地震波输入下，水平向加载作用下坡面峰值位移略大于垂直向加载，有裂隙斜坡坡肩处位移值约为无裂隙斜坡的1.5倍。通过对比坡面不同高度处的PGA放大系数，表明两类斜坡水平向的加速度放大效应大于垂直向放大效应，并在坡肩达到最大值，呈现出高程效应与趋表效应；有裂隙斜坡坡肩处的PGA放大系数明显大于无裂隙斜坡。

Shaking table test study of displacement and acceleration response characteristics of loess slope surface

Based on the loess slope of Pingliang District, the comparative shaking table model test of fissured loess slope and non-fissured loess slope is carried out to study the displacement and acceleration response of loess slope under seismic loading. Through the 3D optical measurement and analysis system, the deformation of the slope surface is obtained with high precision and real time. The experimental results show that with the increase of the input seismic load, the PGD of the fissured loess slope surface and the non-fissured loess slope surface show a trend of increasing with the increase of the slope height; under the same seismic wave input, the horizontal loading effect the peak displacement of the slope surface is slightly larger than the peak displacement of the slope surface under the vertical loading, and the displacement at shoulder of the fissured slope is about 1.5 times that of the non-fissured slope. By comparing the PGA amplification factors at different elevations of the slope, it is shown that the acceleration amplification effect of the horizontal slope of the two types of slopes is greater than the vertical direction, and the maximum value is obtained at the shoulders, showing the elevation effect and the surface effect; the amplification coefficient of PGA at the shoulder of fissured slope is obviously larger than that of non-fissured slope.