地震动力响应下库岸边坡高程放大效应与牵引式失稳机制研究OA

To address the instability of reservoir bank slopes in high-seismicity regions,this study takes a landslide at a reservoir in Yunnan as the research object.Based on field monitoring data and dynamic time-history analysis,a finite difference numerical model is established to reveal the stability evolution mechanism under seismic dynamic response.The results indicate that:1)The peak acceleration at the upper part of the slope reaches 1.6g(while only 0.4gat the lower part),with a velocity variation difference of up to 11 times,confirming the increase in seismic wave energy with slope elevation;2)Under seismic action,the maximum displacement at the lower part of the slope reaches 79.18 cm,and the safety factor drops to 0.883,triggering retrogressive sliding failure,with the displacement magnitude increased by approximately 9 times compared to normal conditions;3)The difference in velocity time-history response leads to uncoordinated movement of the slope mass,where the high-speed moving soil at the upper part(velocity about 0.60 m/s)continuously pulls the lower geotechnical body,causing attenuation of friction at the contact surface;4)The high-risk instability area is concentrated in the upper part of the slope,and it is recommended to adopt targeted support measures such as anti-slide piles to inhibit the development of retrogressive sliding.This research provides a theoretical basis for the seismic design of reservoir bank slopes in strong earthquake zones.