Finite element analyses of slope stability problems using non-associated plasticity
Finite element analyses of slope stability problems using non-associated plasticity作者机构:Institute of Soil Mechanics Foundation Engineering and Computational Geotechnics Graz University of Technology
出 版 物:《Journal of Rock Mechanics and Geotechnical Engineering》 (岩石力学与岩土工程学报(英文版))
年 卷 期:2018年第10卷第6期
页 面:1091-1101页
核心收录:
学科分类:07[理学]
主 题:Finite element limit analysis(FELA) Finite element method Slope stability Strength reduction technique Non-associated plasticity Adaptive mesh refinement Initial stresses
摘 要:In recent years, finite element analyses have increasingly been utilized for slope stability problems. In comparison to limit equilibrium methods, numerical analyses do not require any definition of the failure mechanism a priori and enable the determination of the safety level more accurately. The paper compares the performances of strength reduction finite element analysis(SRFEA) with finite element limit analysis(FELA), whereby the focus is related to non-associated plasticity. Displacement-based finite element analyses using a strength reduction technique suffer from numerical instabilities when using non-associated plasticity, especially when dealing with high friction angles but moderate dilatancy angles. The FELA on the other hand provides rigorous upper and lower bounds of the factor of safety(FoS) but is restricted to associated flow rules. Suggestions to overcome this problem, proposed by Davis(1968), lead to conservative FoSs; therefore, an enhanced procedure has been investigated. When using the modified approach, both the SRFEA and the FELA provide very similar results. Further studies highlight the advantages of using an adaptive mesh refinement to determine FoSs. Additionally, it is shown that the initial stress field does not affect the FoS when using a Mohr-Coulomb failure criterion.