基于统一强度理论的临坡地基极限承载力解答  

A Solution of the Ultimate Bearing Capacity for Foundations near Slopes Based on the Unified Strength Theory

作　　者：赵均海[1] 晏青[1] 张常光[1] Zhao Junhai;Yan Qing;Zhang Changguang(School of Civil Engineering,Chang'an University,Xi'an 710061,P.R.China)

机构地区：[1]长安大学建筑工程学院,西安710061

出　　处：《地下空间与工程学报》2022年第3期801-809,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51878056);陕西省科技计划社会发展领域项目(2019SF-256);地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2020K022);长安大学中央高校基本科研业务费专项资金项目(300102289720)。

摘　　要：基于统一强度理论,综合考虑中间主应力、基底至坡肩水平距离和坡角的影响,推导了条形基础下临坡地基的极限承载力解答,给出其适用条件和计算步骤,讨论与水平地基极限承载力公式的差异,分析所得解答的可比性,并对比文献模型试验结果和上限法解答进行验证,最后探讨各参数的影响特性。研究表明:本文极限承载力解答可退化为Mohr-Coulomb强度准则解答并得到一系列新强度准则解答,具有很好的可比性;与文献模型试验结果和上限法解答吻合良好,验证了所得解答的正确性;中间主应力对临坡地基极限承载力的增强作用显著,未考虑中间主应力效应的结果偏于保守;临坡地基极限承载力随基底至坡肩水平距离的增加逐渐增大,当达到临界距离时与水平地基的极限承载力一致;坡角的增加导致临坡地基极限承载力大幅减小,且中间主应力效应较大时承载力降低的更加明显。本文解答可为临坡地基优化设计提供一定的理论参考。Based on the Unified Strength Theory, a solution of the ultimate bearing capacity for strip foundations near slopes was derived by taking the comprehensive effects of intermediate principal stress, the horizontal distance of foundation base from the slope shoulder and the slope angle into account. Applicable conditions and calculation procedures of the obtained solution were provided, and differences from the ultimate bearing capacity equation of strip foundations on the level ground were discussed. Then, comparability analysis of the proposed solution was conducted, and the proposed solution was verified by comparing with results of the model test and the upper bound method available in the literature. Finally, the influence of each parameter was analyzed. It is found herein that the solution of ultimate bearing capacity in this study has good comparability, which can be degraded into the solution of Mohr-Coulomb strength criterion, and a series of solutions for new strength criteria could be obtained. Results of this study have a good agreement with that of the model test and the upper bound method, thus the correctness of the proposed solution is demonstrated. The intermediate principal stress has an obvious improvement effect on the ultimate bearing capacity of strip foundations near slopes, and the result without considering the intermediate principal stress effect tends to be conservative. The ultimate bearing capacity of strip foundations near slopes gradually increases with the increase of the horizontal distance of foundation base from the slope shoulder, and it is consistent with that of strip foundations on the level ground when the distance from the slope shoulder is equal to a critical value. Furthermore, the increase in the slope angle brings a remarkable reduction in the ultimate bearing capacity, and the reduction is more significant with the greater effect of intermediate principal stress. The result obtained in this study can provide a theoretical reference for optimization design of foundations

关 键 词：极限承载力 临坡地基 条形基础 统一强度理论 

分 类 号：TU470[建筑科学—结构工程]