关键词: 极限抗拔力, 水平条形浅锚, 上限定理, 线性破坏准则, 关联流动法则, 序列二次规划法

Abstract:

Soil anchors are commonly used as foundation systems for structures that require uplift or lateral resistance. Based on the upper bound limit analysis theorem, the linear Mohr-Coulomb failure criterion and associated flow rule, the ultimate pull-out capacity (UPC) of strip anchors is studied by means of the kinematical approach of limit analysis theory. The shear strength parameters (internal friction angle ? and cohesive force c) are treated as variable parameters and two new kinds of knematically admissible failure mechanisms are considered for the calculation schemes. The objective functions of UPC are obtained by equating the work rate of external force to internal dissipation along the velocity discontinuities; and then the upper bound solutions are presented by applying a nonlinear sequential quadratic programming (SQP) algorithm. The calculation results are compared with the available empirical and numerical results presented in the existing literatures, and the validity of present method could be illuminated. From the parameters analysis results, the UPC of new kinds of knematically admissible failure mechanisms is no significant difference. It also can be seen that the density of soil mass, the shear strength parameters (? and c), the embedment ratio and the plate geometric properties have significant effects on UPC and the region of failure modes.

Key words: ultimate pull-out capacity (UPC), strip anchor plates, upper bound theorem, linear failure criterion, associated flow rule, sequential quadratic programming (SQP)