岩质高陡边坡地震动响应规律的振动台试验研究  

Shaking Table Model Tests on the Seismic Response of a High and Steep Rock Slope

作　　者：付晓[1] 杨长卫[1] 韩宜康[2] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]南京铁道职业技术学院,江苏南京210031

出　　处：《地震工程学报》2016年第5期775-782,807,共9页China Earthquake Engineering Journal

基　　金：交通运输部建设科技项目(2013318800020)

摘　　要：设计并完成了1∶10大比例尺的边坡大型振动台模型试验,试验模型尺寸为4.4m×4.4m×1.8m(长×宽×高),斜坡模型表面包含30°、45°、50°、60°四个不同坡度的坡面,模拟岩体材料采用重晶石粉、河砂、石膏、黏土和水按比例配制而成。通过输入不同类型、幅值、频率的地震波来研究模型边坡的动力响应规律,在试验数据分析中采用三维局部坐标系。试验结果表明:边坡临空面方向和竖直方向的加速度高程放大效应随坡面角度的增大而增强,在坡面角度由45°→50°变化时增长趋势呈明显"台阶状"形式,而边坡走向方向的峰值加速度高程放大效应基本不随坡面角度变化;边坡各向的峰值加速度的高程放大效应随着输入地震波幅值的增大而减小,表现出"量级饱和"特性;加速度傅里叶谱的频谱成分随着高程的增大,边坡岩体对于试验模型自振频率f周围的频率成分具有显著的放大作用,而对于其他频率成分则具有滤波作用;加速度反应谱沿高程的形状基本一致,并且卓越周期对应的反应谱幅值沿高程具有一定的放大作用,而在其他周期T处,尤其是长周期部分(低频部分)则存在一定的减小作用,对于临空面方向来讲,具有明显的波峰现象。试验结果有助于揭示边坡在地震作用下的失稳机制,为边坡工程的抗震设计提供有益的参考。A large-scale shaking table model test of a slope with a height of 1.8m,length of 4.4m,and width of 4.4 m was introduced.The materials are made of blanc fixe,river sand,gypsum,clay,and water in different ratios.The slope comprises 30°,45°,50°,and 60°inclined surfaces.A series of tests were performed for different seismic waves,amplitudes,and frequencies.The results indicate that the local coordinate system is more adequate than the whole coordinate system when conducting research on the dynamic problems of the slope.Thus,we should use the airport surface direction L,the strike direction M,and the vertical direction N.The amplifications of the peak accelerations gradually increase with the increase of slope angles,and there are two inflection points at 45°and 50°.However,the amplification along the slope strike direction is consistent.The amplifications of the accelerations in different directions gradually reduce with the increase of the peak ground acceleration of the input wave,which is an intensity saturation phenomenon.Simultaneously,there are predominant peak values in the airport surface direction L;however,there are no predominant peak values in the strike direction M and in the vertical direction N.Therefore,the results reveal the mechanism of slope instability during an earthquake and provide seismic design references for slope engineering.

关 键 词：岩质边坡 动力响应 振动台试验 地震动参数 

分 类 号：TU457[建筑科学—岩土工程]