顺层岩体边坡地震动力破坏离心机试验研究

CENTRIFUGE MODELLING TESTS ON DYNAMIC FAILURE OF BEDDING ROCK SLOPES

使用相似材料分别制作只含有非连续的层面和同时含有非连续的层面和非贯通的次级节理顺层岩体边坡小比例物理模型,进行离心机动力试验,研究边坡的动力响应和破坏机制以及非连续层面和次级节理对其的影响。试验结果证明:顺层边坡的动力响应对地震波的频率和边坡内部结构面的发育特征敏感,边坡结构面发育越复杂,边坡对地震波的频率响应越复杂,地形放大效应也越明显;顺层边坡的动力稳定性和破坏机制受结构面发育特征控制,含有次级节理的边坡动力稳定性更低,破坏范围也更浅,在破坏过程中还会出现次级节理的张拉破坏导致的岩体内部解体破碎,可能诱发岩石碎屑流。

Two types of physical models of sliding rock slope, one with the intermittent rock planes alone and the other with both the rock planes and secondary rock joints were built using similar materials, and tested in the centrifuge machine under different seismic loads. The dynamic response and failure mechanism of the two slope models were then recorded and analyzed. The test results revealed that the dynamic response of the sliding rock slope was sensitive to the frequency of input seismic load and the characteristics of the joint structure inside. The more complex the joint structures are, the more complex the response to the input load frequency and the greater the topographic amplification effect. The dynamic stability and failure mechanism is strongly affected by the joint structure characteristics of the rock slope mass. The rock slope model with both intermittent rock bedding planes secondary rock joints has the lower dynamic stability and a shallower failure plane than the model with only the bedding planes. The tensile failures of the secondary rock joints during the dynamic failing process give rise to the internal crash and lead to the rock debris flow.