非线性破坏准则下水平浅埋条形锚板抗拔承载力的极限分析

发布时间：2018-12-19 08:12

【摘要】：基于非线性Mohr-Coulomb强度准则,根据相关联的流动法则,构造出条形锚板上方土体破坏的机动许可场,利用极限分析上限法,结合变分原理,推导出了水平浅埋条形锚板极限抗拔力的表达式与极限状态下对应的土体破裂机制,讨论了不同锚板设计参数与土体强度参数,对锚板极限抗拔力与土体破裂机制的影响,并将该文计算结果与不同计算方法对应计算结果进行了对比。计算表明:随着锚板埋置深度、土体初始粘聚力与重度的增加,锚板的极限抗拔力不断增大;该文提出的土体破裂机制,与现有文献中的试验结果一致,破裂曲面的形状主要取决于非线性系数m的大小,而且非线性系数m对锚板极限抗拔力也有着显著的影响,随着非线性系数m增加,锚板抗拔力非线性不断降低,土体破裂范围不断减小,破裂曲面的曲率则不断增加,当m=1.0时,破裂曲面退化为一平直面。该文上限解计算结果与现有文献计算成果以及数值计算结果非常接近,从而证明了该计算方法的有效性,为条形锚板的设计提供一定参考。
[Abstract]:Based on the nonlinear Mohr-Coulomb strength criterion and the associated flow rule, the mobile permission field of soil failure above the strip anchor plate is constructed. The upper limit method of limit analysis is used to combine the variational principle. The expression of ultimate pull-out force of horizontal shallow-buried strip anchor plate and the corresponding failure mechanism of soil under the limit state are derived. The influence of different design parameters of anchor plate and soil strength parameter on ultimate pull-out force of anchor plate and failure mechanism of soil is discussed. The results of this paper are compared with the corresponding results of different calculation methods. The calculation results show that the ultimate pullout strength of the anchor plate increases with the increase of the initial cohesive force and the gravity of the soil mass with the embedded depth of the anchor plate. The fracture mechanism proposed in this paper is consistent with the experimental results in the existing literatures. The shape of the fracture surface is mainly determined by the magnitude of the nonlinear coefficient m, and the nonlinear coefficient m has a significant effect on the ultimate uplift force of the anchor plate. With the increase of nonlinear coefficient m, the tensile force of anchor plate decreases continuously, the fracture range of soil decreases, and the curvature of fracture surface increases continuously. When m = 1.0, the fracture surface degenerates into a straight plane. The results of the upper bound solution are very close to those of the existing literature and numerical results, which proves the validity of the method and provides a certain reference for the design of strip anchor plates.
【作者单位】：山东大学岩土与结构工程研究中心;兖矿集团有限公司博士后科研工作站;
【基金】：国家自然科学基金青年科学基金项目(51304125) 高等学校博士学科点专项科研基金项目(20130131120090) 山东省优秀中青年科学家科研奖励基金项目(BS2013NJ004)
【分类号】：TU476;TU43

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