摘要
目前针对近基坑隔离桩控制坑外土体侧向变形的机理研究较为欠缺。本文以宁波地铁一号线某区间附属基坑及隔离桩工程为依托,采用考虑土体小应变特性的硬化土本构模型(HS-Small),建立三维计算分析模型,通过现场实测数据与工程原型计算结果的对比分析对模型及参数进行了验证。然后针对内置式及门架式这两种近基坑隔离桩布置形式进行了深入研究。研究结果表明,门架式隔离桩对近基坑侧浅层土体侧向变形具有较好的控制作用,但对深层以及距基坑较远侧土体的控制效果较差,甚至出现负效果的情况;内置式隔离桩对坑外土体侧向变形均有一定的控制作用。基于位移不动线,可定性判断隔离桩对坑外土体侧向变形的控制作用。
At present,there are few researches on the mechanism of controlling lateral deformation of soil outside the foundation pit by isolation piles near the foundation pit.Based on the auxiliary pit and isolation pile project of a certain section of Ningbo Metro Line 1,this paper uses a hardened soil constitutive model(HS-Small)that takes into account the small strain characteristics of the soil to establish a three-dimensional calculation and analysis model.The model and parameters were verified through a comparative analysis of field measured data and calculation results of the engineering prototype.Then,the built-in type and gantry type of near foundation pit isolation piles are studied in depth.The research results show that the gantry type isolation piles have better control of lateral deformation of shallow soil near the side of the foundation pit,but the control effect on the deep layer and the soil farther from the foundation pit is poor,and even negative effects appear.The built-in type isolation pile has a certain control effect on the lateral deformation of the soil outside the pit.Based on the displacement fixed line,the controlling effect of the isolation pile on the lateral deformation of the soil outside the pit can be judged qualitatively.
作者
徐超
王金昌
Xu Chao;Wang Jinchang(Institute of Transportation Engineering,Zhejiang University,Hangzhou 310058,China)
出处
《科技通报》
2020年第9期32-41,共10页
Bulletin of Science and Technology
基金
浙江省交通运输厅科技项目(2019058)
浙江省公路管理局科研项目(2018H19)。
关键词
基坑开挖
土体侧向变形
内置式隔离桩
位移影响区
位移不动线
excavation of foundation pit
lateral deformation of soil
built-in type isolation pile
displacement affected area
displacement fixed line
