水平地震力作用下顺倾结构面对岩质边坡破坏影响分析

INFLUENCE OF STRUCTURAL PLANE TO FAILURE OF ROCK SLOPE UNDER SEISMIC LOADING

基于断裂理论和波动理论对水平地震力作用下对岩质边坡顺倾结构面的破坏建立了数学模型,在不考虑结构面填充物的影响下分析了结构面的长度、埋深及倾角在水平地震动力作用下对边坡破坏的影响。分析结果表明,当结构面埋深与长度h/L相差不大时,对于一定的水平地震加速度a,结构面埋深和长度越大,边坡在地震作用下越容易破坏;当结构面埋深和长度一定时,边坡破坏随着水平地震加速度的增大而增强。另外,结构面的倾角在增大过程中,岩体所受的拉应力逐渐增大,剪应力则表现为先增大,后减小。这是由于当结构面的埋深与长度一定时,随着倾角的增大,地震作用下边坡是从剪切破坏逐渐向拉张破坏过渡。该模型对地震作用时边坡稳定性分析具有一定的参考意义。

The vertical vibration of seismic wave attenuates faster than its horizontal vibration. Therefore only horizontal seismic force is considered in the mathematic model to analyze the failure of rock slope. The influence of length,buried depth and orientation of the structural plane to the failure of slope are analyzed respectively. It is found that when the buried depth and the length h / L are in a similar value,for a certain horizontal seismic acceleration a,the destruction of slope would be easier to occur with the increase of buried depth and length. While when the buried depth and length are keep in constant values,the failure of slope would become easier with the augment of horizontal seismic acceleration. Moreover,with the enlarge of inclination of structural plane,the tensile stress in rock masses would increase gradually. While the shear stress would boost at first and then decrease. This can be attributed to the reason that the failure of rock masses under earthquake would change from shear state to tensile state when the length and buried depth of structural plane are keep in constant. Moreover,according to the superstition principle of wave,the influence of length and buried depth to the dynamic response of slope under seismic loading is explored as well. The results can be referred to the assessment of seismic stability of slope.