摘要
利用ANSYS有限元软件,结合强度折减法原理提出一种新式突变判据,用以分析三维边坡稳定性。首先模拟整个边坡等效塑性应变全过程,得到边坡变形破坏的动态机制;再以边坡的3种整体位移和5种塑性应力应变为依据,采用最小二乘法对边坡位移值和塑性应力应变值与折减系数关系进行非线性拟合,从理论上计算出边坡极限平衡状态下的安全系数,最后与2种传统判据进行了对比分析。结果表明:随着折减系数的增大,边坡会由土质滑坡转变为岩质滑坡,该边坡使用传统判据所得安全系数为1.1~1.11,结果偏于保守。采用新式突变判据的位移指标的所得安全系数为1.238,塑性指标所得安全系数为1.1296,均处于极限平衡状态,采用极限平衡法对比验证,结果可行。对边坡位移值和塑性应力应变值与折减系数关系进行拟合,Vigot曲线拟合效果最优。该新式判据在理论上为边坡稳定性分析提供了一种新的判断方法。
Using ANSYS finite element software and combining the principle of strength reduction,a new abrupt criterion is proposed to analyze the stability of 3 d slope.First,the whole process of equivalent plastic strain is simulated to obtain the dynamic mechanism of slope deformation and failure.Based on three kinds of overall displacement and five kinds of plastic stress and strain of the slope,the least square method is used to fit the nonlinear relation between the displacement value of the slope and the plastic stress and strain value and the reduction coefficient.The results show that the slope will change from soil landslide to rock landslide with the increase of reduction coefficient.The safety coefficients of the displacement index and the plastic index obtained by the new mutation criterion are 1.238 and 1.1296 respectively,which are in the state of limit equilibrium.The relation between the slope displacement value and the plastic stress-strain value and the reduction coefficient was fitted,and the Vigot curve had the best fitting effect.The new criterion provides a new method for slope stability analysis in theory.
作者
谢旭奎
张杰
XIE Xukui;ZHANG Jie(Hunan Zhili Science and Technology Co.,Ltd.,Changsha,Hunan 410000,China)
出处
《公路工程》
北大核心
2020年第3期124-133,148,共11页
Highway Engineering
基金
湖南应急管理科技项目(201907)。
关键词
突变判据
有限元强度折减法
ANSYS
三维边坡
mutation criterion
finite element strength reduction method
ANSYS
three-dimensional slope
