主动区加固控制邻近基坑桩基础变形分析

Influence Analysis of Active Zone Reinforcement on Pile Foundation Adjacent to Excavation

在目前的基坑设计中,往往不考虑基坑开挖对邻近桩基础的影响。但随着基坑工程往大、深方向发展,尤其在建筑密集城市中新建工程往往与周边建筑非常近,基坑开挖对邻近桩基础的影响不容忽视。除加强围护结构刚度、坑内被动区加固外,坑外主动区加固由于切断或减小了基坑开挖引起的土体位移传播,因而可以有效地控制基坑开挖对邻近桩基础的影响。通过有限元弹塑性分析,讨论了加固范围、加固程度等对桩基侧向变形的影响,对坑外主动区加固效果进行了理论分析,可为基坑变形控制及地基处理提供一定的理论指导。

The effect on the pile adjacent to deep excavation is not always taken into account when designing a retaining wall,at present time.With the development of urban construction,new foundation pits become larger and deeper and are always very close to the surrounding buildings in a crowded city.So the influence of deep excavation on adjacent pile should not be ignored.Besides increasing the strength of retaining wall and reinforcement at passive zone in the pit,the reinforcement at active zone outside the pit should be implemented to control the displacement spread of soil around the pit,as well as decrease the influence to the adjacent piles foundation.Through FEM elastic-plastic analysis,the influence of reinforcement area and degree to pile lateral displacement is discussed.Some valuable conclusions are drawn for practice in pit reinforcement and ground treatment.