上海软黏土深基坑在机开挖离心模型试验研究  

Centrifuge model tests on excavation in Shanghai soft soil layers using in-flight excavation tools

作　　者：马险峰[1,2] 曹明洋 Ma Xianfeng;Cao Mingyang(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《土木工程学报》2023年第8期131-139,共9页China Civil Engineering Journal

摘　　要：基坑变形的预测和控制对于确保基坑自身及周围环境的安全尤为重要。通过设计一种能够在高离心力场中实现深基坑开挖和支撑的模型试验系统来模拟柔性围护结构支护的黏土基坑开挖及支撑的全过程,并与预测基坑变形的方法进行对比分析。研究结果表明:该装置能有效模拟高离心力场试验条件下的基坑开挖;在悬臂开挖阶段,挡墙围绕墙趾附近一固定点做旋转运动,且墙体的最大挠度位于墙顶处。墙后地表沉降曲线为拱肩型,地表最大沉降发生在挡土墙附近;在多支撑开挖阶段,挡墙的变形曲线呈凹槽形,挡墙的最大位移发生在开挖面。地表沉降曲线呈凹槽形发展,地表最大沉降位置位于墙后一固定点附近,且不随开挖深度而变化。The magnitude of wall displacement and the ground settlement profile during excavation are vital in assessing potential damage to neighbouring structures and buried services.A new device for the centrifuge model testing on whole process of excavation was developed.The device was confirmed to be effective in simulating the excavation of foundation pits at the 85-g level by a series of small-scale centrifuge model tests.For unstrutted excavation,the movement of the retaining wall was similar to rotating about a fixed point near the wall toe and the maximum incremental cantilever wall deflection was at the wall crest.The ground settlement curve is spandrel and the maximum settlement occurs near the retaining wall.For the strutted excavation,the movement of the retaining wall was concave settlement trough,and maximum deformation point of the retaining wall was located near the excavation face.The ground settlement curve is concave one,and the maximum ground settlement usually occurs at the same distance from the retaining wall.

关 键 词：基坑开挖 离心机模型试验 在机开挖装置 挡墙位移 地表沉降 

分 类 号：TU447[建筑科学—岩土工程]