长江科学院院报 ›› 2019, Vol. 36 ›› Issue (6): 60-67.DOI: 10.11988/ckyyb.20171282

• 岩土工程 • 上一篇    下一篇

一种黏土层中深基坑开挖地表沉降预测方法

胡之锋1,2, 陈健1,2, 邱岳峰1,2, 李健斌1,2   

  1. 1.中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室,武汉 430071;
    2.中国科学院大学, 北京 100049
  • 收稿日期:2017-11-07 出版日期:2019-06-01 发布日期:2019-06-12
  • 作者简介:胡之锋(1990-),男,湖北孝感人,博士研究生,主要从事随机场理论及其在基坑开挖变形、控制指标方面的应用研究。E-mail:huzf524@163.com
  • 基金资助:
    中国科学院重点部署项目、百人计划项目(KZZD-EW-TZ-12);中国科学院科技服务网络计划项目(KFJ-EW-STS-122)

A Simplified Method for Predicting Ground Surface Settlement Induced by Deep Excavation of Clay Stratum

HU Zhi-feng1,2, CHEN Jian1,2, QIU Yue-feng1,2, LI Jian-bin1,2   

  1. 1.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China;
    2.University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-11-07 Online:2019-06-01 Published:2019-06-12

摘要: 基坑围护结构水平移动是其周围地表沉降的主要诱因之一。基于不同围护结构水平变形模式,根据线弹性理论相关研究给出了对应的地表沉降计算式。通过该计算式预测的黏土层中地表沉降最大值位置xm与实测数据较为吻合。首先采用该计算式求出地表沉降最大值位置;其次,联合地层损失法,基于假设地表沉降曲线,计算沉降影响范围x0,推导地表沉降曲线包络面积Av;最后,根据地表沉降面积Av与围护结构侧移面积Ah之间的相关性,计算地表沉降最大值δmax,从而实现墙后任意地表位置沉降的计算。通过工程实例,验证了该方法的工程适用性。研究成果为基坑开挖地表沉降预测提供了一套半理论半经验方法。

关键词: 地表沉降预测, 深基坑, 黏土层, 挡墙水平位移, 解析解, 地层损失法

Abstract: Horizontal displacement of retaining structure is the main cause of ground surface settlement in deep excavation. In this paper we propose a method of estimating the ground surface settlement. First of all we assume that the ground surface settlement curve is a Gaussian probability density function, and derived the analytical formula of ground settlement under different lateral deformation modes of retaining wall based on linear elastic theory. Subsequently we acquired the location xm of maximum settlement (which is defined as the distance xm from the location of maximum settlement to foundation pit edge) in clay stratum based on the analytical formula, and then calculated the settlement-influenced range x0 based on the aforementioned assumed function of ground settlement in association with soil loss theory. Furthermore, we derived the area Av enveloped by the ground settlement curve, and in the meantime obtained the maximum ground settlement δmax according to the relation between Av and Ah, which is the area enveloped by the lateral displacement curve of retaining wall. The ground settlement of arbitrary location behind retaining wall hence can be estimated by substituting δmax in the aforementioned assumed function. Through several engineering cases we proved that the proposed method is applicable, and thus providing a semi-theoretical and semi-empirical approach to predicting ground surface settlement.

Key words: ground surface settlement prediction, deep foundation pit, clay stratum, horizontal displacement of retaining wall, analytical solution, the soil loss theory

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