(1 华东建筑集团股份有限公司, 上海 200011; 2 华东建筑设计研究院有限公司, 上海 200002;3 上海隧道工程有限公司, 上海 200002)

摘要: 上海苏州河段深层排水调蓄管道系统工程中的苗圃竖井基坑直径 30m,挖深 56. 3m,为软土地区超深圆形基坑工程. 由于原设计逆作内衬墙方案多达 15 个施工工况,施工组织难度大,提出了竖向设置 5 道环梁的顺作优化方案. 基坑开挖前采用三维 m 法,考虑土与结构共同作用的三维有限元法分别对优化方案和原设计方案进行了模拟分析. 结果表明:优化方案的地下连续墙满足承载力要求,验证了优化方案的可行性. 采用优化方案实施的苗圃竖井基坑实测数据与计算结果规律基本一致;地下连续墙侧向变形很小,对周边建(构)筑物影响也很小;地下连续墙表现出以环向轴压为主、竖向受弯为辅的受力性态. 苗圃竖井基坑采用顺作优化方案,实施顺利并取得了良好的技术经济效果,为软土地区类似超深圆形基坑工程设计和施工提供了借鉴.

关键词: 超深圆形基坑; 软土; 三维分析; 优化方案; 变形性状

中图分类号:TU318+.1 文献标志码:A 文章编号:1002⁃848X(2022)10⁃0001⁃10

DOI:10. 19701 / j.jzjg.20211998

Optimal design and practice of a 56m ultra⁃deep circular excavation in soft soils

WANG Weidong1, XU Zhonghua2, ZONG Ludan2, ZHU Yanfei3, WENG Qiping2

(1 East China Construction Group Co., Ltd., Shanghai 200011, China; 2 East China Architecture Design & ResearchInstitute Co., Ltd., Shanghai 200002, China; 3 Shanghai Tunnel Engineering Construction Co., Ltd., Shanghai 200002, China)

Abstract: The diameter and excavation depth of the Miaopu shaft circular excavation of the deep tunnel sewerage project ofSuzhou River in Shanghai were 30m and 56. 3m, respectively, which was a ultra⁃deep circular excavation project in softsoils. In original design, the shaft would be excavated in 15 steps using top⁃down method. This would bring great difficultiesto construction organization. Therefore, an optimized bottom⁃up construction scheme with 5 ring beams was proposed. Threedimensional beam⁃spring model method and three dimensional finite element method considering the interaction of soils andstructures were used to simulate and analyze the original and the optimized construction scheme of the deep excavation. Theresults show that the diaphragm wall could sustain the lateral pressure during excavation using the optimized bottom⁃upconstruction scheme. Monitoring results showed that deformation of the circular diaphragm wall and the adjacent facilitieswere very small. The diaphragm wall was mainly subjected to circumferential axial compression and supplemented byvertical bending. These monitoring results were consistent with the calculation results. Good technical and economic result shave been achieved using the optimized bottom⁃up construction scheme and this provides a reference for the design andconstruction of similar ultra⁃deep circular excavation in soft soil area.

Keywords:ultra⁃deep circular excavation; soft soil; three dimensional analysis; optimal scheme; deformation behavior

∗上海市科学技术委员会科研计划项目(No.13231201006).

第一作者:王卫东,博士,全国工程勘察设计大师,教授级高级工程师,主要从事岩土工程研究,Email: weidong _wang@arcplus.com.

[引用本文] 王卫东,徐中华,宗露丹,等. 软土地区 56m 深圆形基坑的优化设计与实践[ J]. 建筑结构,2022,52(10):1⁃10. WANG Weidong,XU Zhonghua,ZONG Ludan,et al. Optimal design and practice of a 56m ultra⁃deep circularexcavation in soft soils[J]. Building Structure,2022,52(10):1⁃10.