Construction of improved rigid blocks failure mechanism for ultimate bearing capacity calculation based on slip-line field theory
来源期刊：中南大学学报(英文版)2013年第4期
论文作者：赵炼恒 YANG Feng(杨峰)
文章页码：1047 - 1057
Key words：ultimate bearing capacity; rough foundation; slip-line field theory; upper bound limit analysis theorem; slip failure mechanism; nonlinear programming method
Abstract: Based on the slip-line field theory, a two-dimensional slip failure mechanism with mesh-like rigid block system was constructed to analyze the ultimate bearing capacity problems of rough foundation within the framework of the upper bound limit analysis theorem. In the velocity discontinuities in transition area, the velocity changes in radial and tangent directions are allowed. The objective functions of the stability problems of geotechnical structures are obtained by equating the work rate of external force to internal dissipation along the velocity discontinuities, and then the objective functions are transformed as an upper-bound mathematic optimization model. The upper bound solutions for the objective functions are obtained by use of the nonlinear sequential quadratic programming and interior point method. From the numerical results and comparative analysis, it can be seen that the method presented in this work gives better calculation results than existing upper bound methods and can be used to establish the more accurate plastic collapse load for the ultimate bearing capacity of rough foundation.
ZHAO Lian-heng(赵炼恒), YANG Feng(杨峰)
(School of Civil Engineering, Central South University, Changsha 410075, China)
Abstract:Based on the slip-line field theory, a two-dimensional slip failure mechanism with mesh-like rigid block system was constructed to analyze the ultimate bearing capacity problems of rough foundation within the framework of the upper bound limit analysis theorem. In the velocity discontinuities in transition area, the velocity changes in radial and tangent directions are allowed. The objective functions of the stability problems of geotechnical structures are obtained by equating the work rate of external force to internal dissipation along the velocity discontinuities, and then the objective functions are transformed as an upper-bound mathematic optimization model. The upper bound solutions for the objective functions are obtained by use of the nonlinear sequential quadratic programming and interior point method. From the numerical results and comparative analysis, it can be seen that the method presented in this work gives better calculation results than existing upper bound methods and can be used to establish the more accurate plastic collapse load for the ultimate bearing capacity of rough foundation.
Key words:ultimate bearing capacity; rough foundation; slip-line field theory; upper bound limit analysis theorem; slip failure mechanism; nonlinear programming method
