Reinforcement strength reduction in FEM for mechanically stabilized earth structures

XUE Jian-feng(薛剑峰)^{1, 2}, CHEN Jian-feng(陈建峰)¹

(1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education
(Tongji University), Shanghai 200092, China;
2. School of Applied Science and Engineering, Monash University, Victoria 3842, Australia)

Abstract:The factor of safety of mechanically stabilized earth (MSE) structures can be analyzed either using limit equilibrium method (LEM) or strength reduction method (SRM) in finite element/difference method. In LEM, the strengths of the reinforcement members and soils are reduced with the same factor. While using the SRM, only soil strength is reduced during the calculation of the factor of safety. This causes inconsistence in calculating the factor of safety of the MSE structures. To overcome this, an iteration method is proposed to consider the strength reduction of the reinforcements in SRM. The method is demonstrated by using PLAXIS, a finite element software. The results show that the factor of safety converges after a few iterations. The reduction of strength has different effects on the factor of safety depending on the properties of the reinforcements and the soil, and failure modes.

Key words:mechanically stabilized earth structures; factor of safety; strength reduction method; iterative method