摘要
由于普通土体本构模型不能反应土体初始应力状态及开挖应力路径,在进行有限元计算时得到的特征点位移也会与工程实际有偏差。选用可以对开挖前边坡土体的初始K0应力状态以及开挖应力路径进行合理描述的修正关口太田模型,对开挖边坡进行有限元计算。根据位移突变判据,采用单因素敏感性分析,对54例简单边坡进行有限元计算,得出与边坡位移量呈正、负关联的基本参量。利用灰色关联分析方法,首次同时考虑了土坡几何参数、物理参数、本构模型等基本参数,将边坡的变形量进行归一化处理,构建以变形量为基础的归一化失稳判据Fu及警戒位移值U1′,从而可以通过实时监控边坡位移及时给出滑坡体的安全性评价。
Ordinary constitutive models of soils cannot reflect the initial stress state of soil and the stress path of excavation, so that the displacements of characteristic points obtained from the finite element calculation may deviate from the actual magnitudes. In this study, the modified Ohta-Sechiguchi anisotropic elastoplastic model, which can reasonably describe the initial K0 stress state of soil before slope excavation and stress path of excavation, is chosen to calculate the excavation slope. According to the criterion of displacement mutation, single-factor sensitivity analyses of 54 simple slopes are carried out by finite element method, and the basic parameters positively and negatively correlated with the slope displacement are obtained. For the first time, the basic parameters of soil slope such as geometric parameters,physical parameters and constitutive models are considered at the same time through the gray correlation analysis method. By normalizing the slope deformation, the normalized instability criterion Fu and the warning displacement value U1′ are constructed on the basis of displacement magnitude. Consequently, the safety evaluation of the landslide mass can be performed timely by real-time monitoring of the slope displacement.
作者
张坤勇
杜伟
王乾坤
Zhang Kunyong;Du Wei;Wang Qiankun(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;Institute of Geotechnical Engineering,Hohai University,Nanjing 210098,China;China Design Group Co ,Ltd ,Nanjing 210014,China;Shanghai Municipal Engineering Design and Research Institute(Group)Co ,Ltd ,Shanghai 200092,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2019年第11期86-96,共11页
China Civil Engineering Journal
基金
国家自然科学基金(41530637,51578214)
中央高校基本科研业务费专项资金(2015B17714)
中国交通建设股份有限公司科技研发项目(2012-ZJKJ-11)
关键词
边坡稳定
失稳判据
修正关口太田模型
归一化变形量
slope stability
failure criterion
modified Ohta-Sechiguchi anisotropic elastoplastic model
normalized deformation
