含软弱夹层锚框支护边坡的地震响应研究  

SEISMIC RESPONSES OF WEAK INTERLAYERED SLOPE WITH ANCHOR-FRAME REINFORCEMENT USING MODEL SLOPE ON SHAKING TABLE

作　　者：吴尚杰[1,2] 蒋宇静[1,3] 邓涛[1] 关振长[1] 

机构地区：[1]福州大学土木工程学院,福州350108 [2]福建建工集团总公司,福州350003 [3]长崎大学工学部,长崎8528521

出　　处：《工程地质学报》2017年第4期1065-1072,共8页Journal of Engineering Geology

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

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。This paper is based on the prototype slope with weak interlayer inclusion and anchor-frame reinforcement at the MK10 ＋ 250 of Zhaoyin Expressway. A 1/30 downscale model slope is designed and shaking table tests with 20 loading cases are then conducted. The influences of slope elevation and seismic wave amplitude on the PGA amplification coefficient and the PEP oscillation coefficient are focused in this paper. The PGA amplification coefficients inside and upon the slope always increase with the slope elevation. Due to the isolation effect of weak interlayer and the reinforcement effect of anchor-frame, however, the acceleration response of slope tends to be entirety and no whiplash effect is presented. The PGA amplification coefficients decease linearly （ at lower elevation） or exponentially（ at upper elevation） with the amplitude of input seismic wave. The PEP oscillation coefficients inside the slop increase linearly with the cover depth, while increase non-linearly with the amplitude of input seismic wave. When excited by the seismic waves with larger amplitude, the additional horizontal pressure towards outside tends to be greater than the counterpart towards inside. The failure characteristic of model slope during shaking table tests is carefully inspected and described. The cracks concentrate in the upper part of slope above the weak interlayer, especially upon the top face of slope. However, no overall instability is presented along the weak interlayer due to the reinforcement effect of anchor-frame.

关 键 词：边坡工程 地震动力响应 振动台试验 软弱夹层 锚框支护 

分 类 号：U41[交通运输工程—道路与铁道工程]