多层土中浅埋板锚的极限抗拔承载力及破坏机理的极限分析

Limit analysis of ultimate uplift capacity and failure mechanism ofshallow plate anchors in multi-layered soils

在一些复杂的情况下,板锚埋在多层岩土材料中。本文旨在利用极限分析的运动学方法,研究多层土中浅埋的条形和圆形板锚的极限抗拔承载力和破坏机理。引入岩土材料的非线性强度准则和非关联流动法则,研究了非均匀性对浅埋板锚的抗拔性能和破坏机理的影响。得到了条形和圆形板锚的破坏曲线或破坏面的表达式,并给出了计算极限抗拔承载力和破坏范围的公式。本文方法得到的结果与数值模拟和前人的研究结果基本一致,证明了本文方法的有效性。研究了不同参数对多层土中板锚的抗拔极限承载力和破坏机理的影响。结果表明,浅埋板锚的极限抗拔承载力和破坏范围随初始黏聚力和剪胀系数的增大而增大,随重度、拉应力和非线性系数的增大而减小。

Considering the fact that in some complex cases,plate anchors are buried in multi-layered geotechnical materials,the ultimate dynamic analysis was performed to investigate the uplift capacity and failure mechanism of shallow strips and circular plate anchors in multi-layered soils.The nonlinear strength criterion and non-associated flow rule of geotechnical materials were introduced to investigate the influence of nonuniformity on the pullout performance and failure mechanism of shallow plate anchors.The expressions of the detaching curves or surfaces were obtained to reflect the failure mechanism,which can be used to figure out the ultimate uplift capacity and failure range.The results are generally in agreement with the numerical simulations and previous research.The effects of various parameters on the ultimate uplift capacity and failure mechanism of plate anchors in multi-layered soils were investigated,and it is found that the ultimate uplift capacity and failure range of shallow anchors increase with the increase of initial cohesion and dilatancy coefficient,but decrease with the unit weight,axial tensile stress and nonlinear coefficient.