含软弱夹层锚框支护边坡的地震响应研究

发布时间：2018-11-23 09:25

【摘要】：以漳州招银高速MK10+250段含软弱夹层岩质边坡的锚框支护工程为原型,设计了1/30缩尺模型边坡,开展了20种工况的模拟地震动试验,重点关注坡体高程、地震动幅值对PGA放大系数和PEP震荡系数的影响。坡内和坡面各测点处PGA放大系数,均呈现出明显的高程效应;但由于软弱夹层的隔震作用和锚框支护的加固作用,使得边坡加速度响应更趋于整体性,不表现出明显的鞭梢效应。坡内和坡面各测点处PGA放大系数,随着输入地震动幅值的增大呈线性减小或指数型减小。各测点处PEP震荡系数随埋深增大呈近似线性增加,随地震动幅值增大呈非线性增加;并且在高烈度工况下,指向坡外方向的附加水平压力大于指向坡内方向。通过对边坡表观破坏特征的描述,发现表观破坏主要集中在软弱夹层上部坡体中,尤其是坡顶表层出现了贯通裂缝;但由于锚索-框架支护的加固作用,其边坡并未沿软弱夹层发生整体性失稳。
[Abstract]:Based on the bolt-frame support project of rock slope with weak intercalation in Zhangzhou Zhaoyin high speed MK10 250 section, a 1 / 30 scale model slope is designed, and 20 simulated ground motion tests are carried out, focusing on the elevation of slope body. The effect of amplitude of ground motion on PGA magnification factor and PEP oscillation coefficient. The PGA magnification factor in the slope and at each measuring point on the slope showed obvious elevation effect. However, due to the isolation of weak intercalation and the reinforcement of bolt-frame support, the acceleration response of the slope tends to be more holistic, without obvious whipping effect. The PGA magnification factor decreases linearly or exponentially with the increase of the amplitude of the input ground motion. The PEP oscillation coefficient increases linearly with the increase of buried depth, and the amplitude of vibration increases nonlinearly with the increase of buried depth, and the additional horizontal pressure pointing to the direction outside the slope is greater than that pointing to the direction inside the slope under high intensity conditions. Through the description of the apparent failure characteristics of the slope, it is found that the apparent failure is mainly concentrated in the upper slope body of the weak intercalation, especially in the surface layer of the slope. However, due to the reinforcement effect of anchor cable-frame support, the slope does not have overall instability along the weak intercalation.
【作者单位】：福州大学土木工程学院;福建建工集团总公司;长崎大学工学部;
【基金】：国家自然科学基金(51678155) 福建省交通运输科技发展项目(201531)资助
【分类号】：U416.14

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