基于强度折减的边坡动力安全系数确定方法研究

地震边坡稳定性分析已成为岩土工程界和地震工程界抗震减灾研究的重要课题之一。通过数值分析对土质边坡地震动力响应规律进行研究,发现边坡上PGA分布突变点的连线与潜在滑动面位置存在较好的对应关系。据此可通过PGA分布突变点的连线轮廓来大致确定边坡的潜在滑裂面,同时,这些PGA分布突变点可以选定为判定坡体临界稳定状态的关键点。基于强度折减法,以关键点的相对位移作为边坡动力破坏的控制性指标,结合地震特征位移和安全系数来评价边坡的动力稳定性,以特征位移与强度折减系数曲线上的特征位移产生突变时对应的强度折减系数作为边坡的地震动力安全系数。

The determination method of dynamic safety factor for slope based on strength reduction

The seismic stability of the slop has become an important research topic in geotechnical and seismic engineering.A numerical model has been set up to analyze the seismic response law of the soil slop.It is revealed that the ligature of PGA catastrophe points has good agreements with the potential sliding surface,thus the potential sliding surface can be determined by the ligature.Also,these PGA catastrophe points can be used as strategic points to distinguish the critical stable state of the soil slop.Based on strength reduction method,the relative displacement of the strategic points can be used as controlling indices of the slop dynamic damage;the dynamic stability of the slop can be assessed along with the seismic features displacement and safety coefficient;the corresponding strength reduction coefficient where features displacement mutations on the features displacement and strength reduction coefficient curve can be used as seismic dynamic safety factor of slop.