临坡抗拔条形锚板破坏模式及极限承载力上限分析与试验验证

Failure Mode of Uplift Strip Anchor Plate Adjacent to Slopes and Upper Limit Analysis and Test Verification of Its Ultimate Bearing Capacity

考虑土体材料的非线性特征,用非线性强度准则及其关联流动法则构造临坡条形锚板上拔时的机动许可速度场,并基于上限定理导出其曲线型破坏模式及抗拔承载力上限解.此后,借助DIC图像关联技术开展了一系列临近砂土边坡条形锚板的室内抗拔模型试验,得到了不同边坡角度及不同临坡比情况下条形锚板的抗拔承载力及上方土体破裂面发展模式.对比结果表明,临坡条形锚板的抗拔承载力与本文上限解计算结果误差在13%以内,土体破裂面模式也基本吻合,从而验证了本文理论解的合理性.最后,对抗拔条形锚板的临界临坡比进行了探讨,分析结果表明临界临坡比随埋置深度和初始黏聚力的增大而增大,随单轴抗拉强度的增大而减小.

Considering the nonlinear characteristic of soil materials,the nonlinear strength criterion and the associated flow rule were used to construct the curved failure mechanism and kinematically admissible velocity field of the strip plate anchor buried near a slope.The curved failure mode and upper bound solution of the uplift bearing capacity were derived based on the upper bound theorem of the limit analysis.Then,with the aid of DIC technology,a series of uplift load tests were conducted in laboratory for scaled strip plate anchor models,which were buried in the horizontal ground or at different distances from a sand slope with various slope angles,and the uplift bearing capacity and the failure mode of the anchors with different slope angles and different edge-distance ratios were obtained.The comparison results show that the error of the uplift bearing capacity from the laboratory tests and theoretical solutions is within 13%,and the failure mode is basically consistent,which verifies the rationality of the theoretical solution.Finally,the critical edge-distance ratio of the uplift strip anchor plates was examined.The analysis results show that the critical edge-distance ratio of the anchor increases with increase of the embedding depth and the initial cohesion,while decreases with the increase of the uniaxial tensile strength.