摘要
以云南香丽高速公路沿线的岩羊村滑坡为研究对象,开展了滑坡动力稳定性评价及失稳机制研究:进行了不同烈度地震下的滑坡稳定性分析,采用滑带弹性区体积占比的变化反映其失稳过程,结合滑坡变形破坏模式,对滑坡整体稳定性进行评价;针对极限地震工况,分别从时间和空间角度描述滑坡失稳过程;建立了同时考虑滑带弱化和硬化的滑坡尖点突变模型,揭示了滑坡失稳的触发机制。研究表明:滑坡在区域Ⅷ度地震烈度条件下基本保持稳定,在锁固段的"锁固作用"下滑坡仅发生局部破坏;滑坡发生整体失稳的临界峰值加速度为2.29 m/s^2,其失稳机制为在前缘牵引、后缘拉裂作用下,滑带塑性区贯通导致的整体失稳;地震作用下滑带前缘、中部、后缘并非同步破坏,表现为累积-触发效应;利用改进尖点突变模型推导了刚度效应失稳判据,揭示了滑坡整体稳定性与滑带介质的刚度及尺寸特性密切相关。研究结果为岩羊村滑坡的防治与抗震设计提供了指导,并可为同类工程的动力稳定性评价与失稳机制分析所借鉴。
Dynamic stability evaluation and failure mechanism research were performed on the Yanyang village landslide along Xiangli expressway in Yunnan province.The landslide stability analysis under different seismic intensities was carried out,the progressive failure of landslide was described by the change in volume ratio of residual elastic zone of slip zone.The dynamic stability of landslide was evaluated by combining with the deformation mode of landslide and the volume ratio of residual elastic zone.For the failure mechanism of landslide under extreme earthquake conditions,the failure process of landslide was described in terms of time and space respectively.A cusp catastrophe model of landslide,which could consider both weakening and hardening section of slip zone,was established and the trigger mechanism was revealed.The results showed that:(1)the landslide under the condition ofⅧdegree seismic intensity remained stable,and only local failure occurred due to the"locking effect"of locking section;(2)The critical peak acceleration of overall failure of the landslide was 2.29 m/s^2,and its failure mechanism was the whole failure caused by the sudden penetration of the plastic zone due to the failure of"locking action"under the coupling action of leading section traction and trailing section tension crack;(3)The leading,middle and trailing section of the slide zone were not destroyed synchronously,but presented a cumulative-triggering process.(4)A failure criterion of stiffness effect was derived based on the improved cusp catastrophe model,the overall stability of the landslide was found to be closely related to the stiffness and size characteristics of the sliding zone medium.The results could offer guidance for disaster prevention and seismic design of Yanyang village landslide,and be used for reference in the dynamic stability evaluation and failure mechanism analysis of similar projects.
作者
杜文杰
盛谦
付晓东
汤华
陈贺
杜宇翔
周永强
DU Wen-jie;SHENG Qian;FU Xiao-dong;TANG Hua;CHEN He;DU Yu-xiang;ZHOU Yong-qiang(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2020年第7期2461-2469,共9页
Rock and Soil Mechanics
基金
国家重点研发计划资助(No.2018YFC0809400)
国家自然科学基金(No.51779250)
中国科学院国际合作局国际伙伴计划项目(No.131551KYSB20180042)
云南省交通科技项目《云交科教[2017]33号》。
关键词
滑坡
地震
动力稳定性
锁固作用
尖点突变理论
启动机制
landslide
earthquake
dynamic stability
locking effect
cusp catastrophe model
trigger mechanism
