Numerical and experimental analyses for bearing capacity of rigid strip footing subjected to eccentric load

LU Liang(卢谅)^{1, 2}, WANG Zong-jian(王宗建)³, K. ARAI⁴

(1. School of Civil Engineering, Chongqing University, Chongqing 400045, China;
2. Key Laboratory of New Technology for Construction of Cities in Mountain Area of Ministry of Education
(Chongqing University), Chongqing 400045, China;
3. Institute of Geotechnical Engineering, Chongqing Jiaotong University, Chongqing 400074, China;
4. NPO Research Institute of Ground Disaster Prevention of Fukui Region, Fukui 910-0004, Japan)

Abstract:A footing may get an eccentric load caused by earthquake or wind, thus the bearing capacity of footing subjected to eccentric load become a fundamental geotechnical problem. The conventional limit equilibrium method used for this problem usually evaluates the material properties only by its final strength. But the classical finite element method (FEM) does not necessarily provide a clear collapse mechanism associated with the yield condition of elements. To overcome these defects, a numerical procedure is proposed to create an explicit collapse mode combining a modified smeared shear band approach with a modified initial stress method. To understand the practical performance of sand foundation and verify the performance of the proposed procedure applied to the practical problems, the computing results were compared with the laboratory model tests results and some conventional solutions. Furthermore, because the proposed numerical procedure employs a simple elasto-plastic model which requires a small number of soil parameters, it may be applied directly to practical design works.

Key words:bearing capacity; eccentric load; slip surface; shear band; finite element method; model test