岩土工程学报2024，Vol.46Issue(8)：1762-1767,1790,7.DOI:10.11779/CJGE20221513
非饱和土基坑抗隆起稳定性研究
Basal anti-heave stability of foundation pits in unsaturated soils
摘要
Abstract
It is known that the soils surrounding a foundation pit are commonly in an unsaturated condition and the displacement of a retaining wall routinely rotates around wall bottom(i.e.,RB displacement mode).The bearing capacity of strip foundations at wall bottom with a single-sided sliding surface and the vertical anti-sliding force of wall-soil system under RB displacement mode with an overall down-sliding are first derived in the framework of the two-stress state variable theory for unsaturated soils.For uniform and linear suction profiles,the limit equilibrium method is then adopted to provide a solving process on the safety factor against basal heave of foundation pits in unsaturated soils,respectively.Finally,based on the verifications of the theoretical solutions reported in the literatures with an engineering case of foundation pits,the influences of different wall displacement modes are explored.The results show that the proposed safety factor against basal heave of foundation pits accounts for unsaturated characteristics of soils and RB displacement mode of a retaining wall.The proposed safety factor compares reasonably well with the available theoretical solutions of both the foundation bearing capacity model and the limit upper bound approach,and it can be naturally degraded to that of saturated soils.The vertical anti-sliding force and the safety factor against basal heave of foundation pits under RB displacement mode of retaining walls are smaller than those under an in-situ state.The safety factor against basal heave of foundation pits is conservative for simplified calculation of unsaturated soils taken as saturated soils ignoring unsaturated strength characteristics.关键词
基坑抗隆起/非饱和土/竖向抗滑力/基质吸力Key words
basal anti-heave of foundation pits/unsaturated soil/vertical anti-sliding force/matric suction分类
建筑与水利引用本文复制引用
张常光,隋建浩,范家燊,徐灏..非饱和土基坑抗隆起稳定性研究[J].岩土工程学报,2024,46(8):1762-1767,1790,7.基金项目
地质灾害防治与地质环境保护国家重点实验室开放基金项目(SKLGP2020K022) （SKLGP2020K022）
长安大学中央高校基本科研业务费专项资金项目(300102282206) （300102282206）
