水平层状岩体边坡动力响应中的结构面效应研究

根据应力波传播原理分析了水平层状岩体边坡中应力波传播特征,建立了应力波在该类边坡中传播的模型。利用离散元软件UDEC分析了不同频率垂向压缩应力波作用下边坡动力响应规律中的结构面效应。结果表明:边坡中的水平层面对坡顶的动力响应有明显影响。低频应力波作用下,水平层状岩体边坡坡顶的垂向峰值速度较均质坡体相同部位的峰值速度的增加值随坡高增加而增大。较高频率应力波作用时,边坡顶部靠近坡面的垂向峰值速度高于无结构面边坡相同部位的峰值速度,远离坡面时情况相反; 坡顶垂向峰值速度大小呈周期性变化,输入应力波频率越大该变化频次越高。研究结果将有助于进一步揭示各种不同岩体结构类型边坡在动力荷载作用下损伤机理及破坏模式。

EFFECT OF STRUCTURAL PLANE ON DYNAMIC RESPONSE OF ROCK SLOPES WITH HORIZONTAL STRAT

Based on the rule of stress wave propagation,the characters of the stress waves propagating in rock slopes with horizontal strata layers are analyzed.A new model about the stress waves propagating in this type of slopes is proposed.The effect of structural plane in dynamic responses of the slopes under periodical compressive load is examined with UDEC.It is revealed that the structural plane plays an important role.Under the action of low frequency compressive waves,the vertical peak ground velocity of slope crest (near sloping surface)is also larger than that of a homogeneous slope at the same position.This effect is more obvious as the slope height increases.Under the action of high frequency compressive waves,the vertical peak ground velocity of slope crest is larger than that of a homogeneous slope at the same position.However,it is less than that of a homogenous slope at positions far away from the sloping surfaces.And the value of the vertical peak ground velocity varies in period from model right to left.The numerical results are conductive to reveal the characteristics of fatigue behavior and failure mechanisms of different kinds of rock slopes.