摘要
地震滑坡的致灾范围是判断滑坡能否会对已有建构筑物造成损失、确定预警疏散范围的重要依据,因此对地震土坡破坏后的滑坡体大小和致灾范围进行研究具有重要的意义。本研究基于SPH动力分析方法,结合弹塑性本构模型和固体力学控制方程建立了地震土坡破坏的动力分析模型;通过设置振动边界粒子和自由场边界粒子,实现了地震动加速度的施加以及自由场边界的模拟。利用提出的SPH动力分析方法,对已有的振动台土坡试验进行了模拟,获得了与试验相似的土坡滑动形态,验证了SPH动力分析方法的准确性和精度。此后,设计了不同坡度土坡的计算案例,考虑地震动加速度幅值的影响进行了SPH动力分析,得到了各种工况下地震土坡失稳后滑坡体的大小和致灾范围。模拟结果表明同一土坡在不同地震动幅值作用下存在相似的滑动面,且潜在滑动区域随着地震动幅值的增大而增加;随着坡度的增大,土坡在不同地震动加速度幅值下的稳定性均呈现下降趋势,致灾范围变大,但滑坡体的区域面积却在减小。
The disaster-causing range formed by the earthquake landslide is an important basis for judging whether the landslide can cause losses to existing structures and determining the early warning evacuation range.Therefore,it is necessary to study the sliding body size and disaster-causing range after the post sliding of soil slopes triggered by the earthquake.Based on the dynamic SPH analysis method,combined with the elastoplastic constitutive model and the governing equation of solid mechanics,we establish a dynamic analysis model for the seismic soil slope failure.By setting the vibration boundary particles and the free field boundary particles,we realize the application of ground motion acceleration and the simulation of the free field boundary.We use the dynamic SPH analysis method to simulate an existing shaking table test for soil slope.And we obtain a sliding form similar to the shaking table test slope from the SPH simulation.This result verifies the accuracy and precision of the dynamic SPH analysis method.Afterwards,we design calculation cases of soil slopes with different slope angles.And we carriy out SPH analysis considering the influence of ground motion acceleration amplitude.Finally we obtain the sliding body size and the disaster-causing range of landslide after instability of seismic soil slopes under various working conditions.The simulation results show that the soil slope has a similar sliding surface under the action of different ground motion amplitudes.And the potential sliding area increases with the increase of the ground motion amplitude.Meanwhile,the stability of the soil slope under different ground motion acceleration amplitudes shows a downward trend.And the disaster-causing range becomes larger,while the sliding body size is decreasing.
作者
张卫杰
余瑞华
宋健
姬建
ZHANG Weijie;YU Ruihua;SONG Jian;JI Jian(Key Lab of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210024,China;College of Civil and Transportation Engineering,Hohai University,Nanjing 210024,China)
出处
《工程地质学报》
CSCD
北大核心
2022年第2期565-574,共10页
Journal of Engineering Geology
基金
国家自然科学基金(资助号:51808192,51890912,41630638)
中央高校基本科研业务费专项资金(资助号:B210202039)。
关键词
SPH动力分析方法
不同地震动幅值
滑坡体大小
致灾范围
SPH dynamic analysis method
Different ground motion amplitudes
Sliding body size
Disaster-causing range
