（浙江华展工程研究设计院有限公司， 宁波 315012）

［摘要］基于宁波软土地区典型土层分布和经工程反演的计算参数，通过MIDAS/GTS有限元分析软件对不同开挖面积和开挖深度的18个三维基坑有限元模型进行数值计算。根据数值模拟结果，提出了确定宁波地区地铁隧道控制保护区范围的修正方法。通过对工程实例的实测结果进行分析，证明了该修正方法的可行性和必要性。进一步对比分析了基坑的开挖面积与深度对邻近隧道位移的影响；通过建立两类不同分坑措施的基坑模型，比较了不同分坑措施在控制基坑和隧道位移方面上的效果。结果表明，隧道最大位移随邻近基坑开挖面积的增加呈非线性递增；采用分隔墙与隧道垂直的分坑措施对隧道位移控制更为有利。研究成果可为宁波软土地区地铁隧道控制保护区内的基坑设计提供参考。

［关键词］隧道保护； 基坑工程； 空间效应； 控制保护区； 数值模拟

中图分类号：TU753文献标识码：A文章编号：1002-848X(2016)02-0091-05

Influence study of spatial effect of deep foundation pit excavation on around

soil and adjacent tunnel

Wu Caide, Zeng Jie, Cheng Yichong, Gong Dikuai

(Zhejiang Huazhan Institute of Engineering Research & Design Co., Ltd., Ningbo 315012, China)

Abstract:Based on the typical soil layer distribution and parameters by engineering back analyses in Ningbo soft soil area, 18 three-dimensional foundation pit finite element models with different excavation areas and depths were numerically calculated by finite element analysis software MIDAS/GTS. According to the numerical simulation results, a modified method was proposed for determining the control and protection area of the subway tunnel in Ningbo. The method′s feasibility and necessity was proved by analyzing field measured results of a practical project. The influences of the excavation area and depth of foundation pits on the displacement of the adjacent tunnel were analyzed. Two foundation pit models with different pit division measures were established to compare the different effects of pit division measures on the displacement control of the foundation pit and tunnel. Results show that maximum displacement of the tunnel increases nonlinearly along with the increase of excavation area adjacent to the tunnel, pit division measure of division walls being in vertical direction to the tunnel is more effective in displacement control of the tunnel. The research achievements can provide references for the foundation pit design in the control and protection area of the subway tunnel in Ningbo soft soil area.

Keywords:tunnel protection; foundation pit engineering; spatial effect; control and protection area; numerical simulation

作者简介：吴才德，教授级高级工程师，注册土木工程师（岩土），Email: 136288336@qq.com。