深基坑开挖过程中立柱受力变化规律分析

Analysis on the Law of the Pillar Bearing Force During Deep Excavation

在基坑开挖过程中,立柱所受水平和竖直方向力处于不断变化状态,变形比较复杂,立柱的稳定对支护结构的安全至关重要,因此有必要研究立柱受力的动态情况。以宁波某地铁基坑为例,基于基坑开挖的时空效应,分析立柱的受力变化规律。分析发现,在基坑开挖过程中,立柱先沉降后隆起,其隆起和沉降的分界点与基坑深度、土体性质有关,也可以此作为划分深、浅基坑的依据,不仅限制了基坑底部隆起,而且提高了基坑的稳定性。

The bearing force of the pillars changes continuously and deformation is complex. The stability of pillars is important to the safety of supporting structure and it is necessary to study the bearing condition of pillars. Taking an example as foundation excavation of some subway in Ningbo, the bearing force law of pillars was analyzed based on time and space effect of excavation. The result shows that the pillars sunk firstly and uplifted then, and the boundary is related to the depth of foundation excavation and soil properties. The deep and shallow foundation excavation is divided according to it. It was found that the pillars confined the changing bottom of foundation excavation and the stability was improved.