摘要
工程中地震边坡稳定性分析通常采用的是拟静力法,该方法往往会忽略除震幅外其他地震动参数对边坡稳定性的影响。本文基于安全系数法和永久位移法,将拟静力法和两种动力稳定性评价方法时程分析法和Newmark位移法做对比。分析不同的地震波形、地震频率、地震持时、地震震幅对边坡稳定性的影响变化规律。结果表明:边坡的稳定性随着输入的地震幅值增大而降低;随着输入的地震动频率与固有频率越接近,共振现象越明显,稳定性越低;当地震动峰值过后,边坡的安全性随着地震持时的变化不明显。地震波波形对边坡安全性影响很大,不能忽略。拟静力法未考虑地震频率、持时和波形的影响,当地震频率与边坡固有频率相近或地震震级较大时,对边坡的稳定性评价不准确。建议在以后的稳定性分析中,采取最小平均安全系数作为评价标准。当安全性系数小于1.05时,结合Newmark位移综合评价边坡的地震稳定性。
The quasi-tatic method is usually used in the stability analysis of seismic slope in engineering,which often ignores the influence of other ground motion parameters on the slope stability except the seismic amplitude.Based on the safety factor method and the permanent displacement method,this paper compares the quasi-tatic method and two dynamic stability evaluation methods,the time history analysis method and the Newmark displacement method.Analyze the changing law of the influence of different earthquake waveforms,earthquake frequencies,earthquake durations,and earthquake amplitudes on slope stability.The results show that the stability of the slope decreases with the increase of the input earthquake amplitude;as the input ground motion frequency is closer to the natural frequency,the resonance phenomenon is more obvious and the stability is lower;The change in safety with the duration of the earthquake is not obvious.The seismic wave shape has a great influence on the slope safety and cannot be ignored.The quasi-tatic method does not consider the influence of earthquake frequency,duration and waveform.When the earthquake frequency is close to the natural frequency of the slope or the earthquake magnitude is large,the stability evaluation of the slope is not accurate.It is suggested to take the minimum average safety factor as the evaluation standard in the future stability analysis.When the safety factor is less than 1.05,the seismic stability of the slope is comprehensively evaluated in combination with the Newmark displacement.
作者
王本栋
李四全
许万忠
谯立家
谭银龙
周谊
WANG Ben-dong;LI Si-quan;XU Wan-zhong;QIAO Li-jia;TAN Yin-long;ZHOU Yi(School of Land Resources and Engineering,Kunming University of Science and Technology,Kunming 650093,China;Southwest Nonferrous Kunming Survey and Design(Institute)Co.,Ltd.,Kunming 650217,China)
出处
《地质灾害与环境保护》
2023年第1期64-70,共7页
Journal of Geological Hazards and Environment Preservation
基金
国家自然科学基金资助项目(41562016)。
作者简介
王本栋(1995-),男,2018年本科毕业于西南交通大学土木工程专业,现为昆明理工大学国土资源工程学院资源与环境-地质工程硕士研究生,主要从事边坡稳定性的研究。E-mail:940001225@qq.com;通讯作者:许万忠(1965-)男,博士,现任昆明理工大学教授,主要从事岩土工程专业研究工作。E-mail:582647881@qq.com。
