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基于完全动力的有限差分强度折减法,对6种判据求解地震荷载作用下顺层岩质边坡动力安全系数的有效性和适用性进行分析,并与刚体极限平衡法的计算结果进行了对比。研究结果表明:塑性区和岩体层面剪切滑移状态贯通判据是判别顺层岩质边坡处于临界失稳状态的必要非充分条件,以其为判据获得的动力安全系数略小于其它判据对应的动力安全系数,工程意义上偏于保守;由于很难事先预知边坡滑裂面的几何形状和位置,层面上下岩体相对位移突变判据、层面剪切滑移位移突变判据和动力安全系数时程判据的普遍适用性较差。建议联合塑性区和层面剪切滑移状态贯通判据以及滑体特征点位移或位移变化速率突变判据,进行地震等动载作用下顺层岩质边坡动力安全系数的求解;为使所选取的特征点具备普遍适用性,可在坡脚至坡顶之间的坡面上间隔一定距离选取监测点,作为监测边坡位移或位移变化速率的特征点。
Based on the method of finite difference strength reduction of full power, the validity and applicability of six kinds of criteria for solving the dynamic safety factor of bedding rock slope under seismic load are analyzed and compared with the results of rigid body limit equilibrium method . The results show that the criterion of penetrating through the shear zone in the plastic zone and the rock mass is a necessary and sufficient condition for judging the bedding rock slope in the critical state of instability. The dynamic safety factor obtained based on this criterion is slightly smaller than the other The dynamic safety coefficient corresponding to the criterion is conservative in engineering sense. Because it is difficult to predict the geometry and location of the sliding surface, the criterion of sudden displacement of upper and lower rock mass, the criterion of sudden shear displacement And the general applicability of the dynamic safety coefficient time history criterion is poor. It is suggested that the joint plasticity zone and the cut-and-slip criterion of shear strata and the criterion of abrupt change of displacement or displacement of the characteristic points of the rock mass be used to solve the dynamic safety coefficient of the rock mass under the dynamic loading such as earthquake. The selected feature points are universally applicable. The monitoring points can be selected at a distance from the slope to the top of the slope to be used as a feature point for monitoring the rate of slope displacement or displacement.