土工基础 ›› 2020, Vol. 34 ›› Issue (2): 135-139.

• 工程实录 • 上一篇    下一篇

软土地区紧邻深大基坑开挖影响分析

陈汉波   

  1. (中铁二院工程集团有限责任公司地铁院,成都 610031)
  • 收稿日期:2020-01-17 修回日期:2020-02-19 出版日期:2020-05-20 发布日期:2020-05-20
  • 作者简介:陈汉波(1989-),男,工程师,研究方向为城市轨道交通地下工程。

Influence of Two Deep Excavations Next to Each Other in Soft Soils

CHEN Hanbo   

  1. (Metro Design & Research Institute, China Railway Eryuan Engineering Group Co. Ltd., Chengdu 610031)
  • Received:2020-01-17 Revised:2020-02-19 Online:2020-05-20 Published:2020-05-20

摘要: 基坑开挖耦合效应影响范围的研究是群坑工程围护结构设计和周边环境保护的关键。以昆明地区地下连续墙支护深基坑工程实例为基础,采用改进的剑桥土体模型,构建不同基坑间距、不同基坑开挖深度的地连墙支护基坑有限元平面应变模型,研究了单基坑开挖后地下连续墙沉降量与水平位移的计算值与实测值之间的关系。通过对不同开挖距离和不同开挖深度的基坑模型计算值的研究,得出基坑开挖对基坑的耦合作用规律。结果表明,计算中所采用的土的本构模型和土的参数是准确的,基坑开挖的耦合效应随着基坑间距的增大而逐渐减小,且衰减速度变慢,基坑开挖耦合效应下限确定为开挖深度的10倍。

关键词: 紧邻, 基坑, 软土地区, 深大基坑, 墙体侧移, 地表沉降

Abstract: The evaluation of the deep excavation coupled influence zone is critical to the deep excavation supporting structure design and the protection of the adjacent buildings and utilities. This paper presents a case history of evaluation a slurry wall as the deep excavation supporting structure. The slurry wall system was simulated by the plane strain finite element model with modified CamClay soil constitutive model. The measured vertical and horizontal deflections in a single deep excavation pit were compared with the numerical analysis results. The required slurry wall dimensions at different spacing between two deep excavation pits, different excavation depths in each pit are investigated. Throughout the parametric studies on the spacing and depth of two adjacent deep excavations, the coupled influence zone was thoroughly evaluated. The results indicated that, the soil constitutive model and other soils parameters used in the analysis are appropriate. The influence of the adjacent deep excavation reduces with the increase spacing between two excavations. The horizontal influence zone can be characterized as ten times of the excavation depth.

Key words: adjacent areas, deep excavations, soft soil area, large deep excavations with great depth, lateral deflection of slurry wall, ground subsidence

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