Deformation Characteristics of Deep Excavations for Metro Stations in Shanghai Soft Soil Deposits

doi:10.16183/j.cnki.jsjtu.2008.11.026

Abstract

Abstract:

The case histories of deformations due to the deep excavations for some metro stations in Shanghai soft soil deposits were presented and discussed. The statistics show that the ratio of the maximum lateral displacement of the retaining structures to the excavation depth ranges from 0.04% to 0.6%, and the mean value is about 0.3%. The deformation of the retaining structures develops a clearly deep-bulging profile as the excavations continue, and the maximum lateral displacement of the retaining structures usually appears between 1.5 m above the excavation surface and 7 m below the excavation surface. The ratio of the maximum surface ground settlement to the excavation depth lies between the range 0.05% to 0.7%, and the ratio of the maximum surface ground settlement to the maximum lateral displacement of retaining structures falls within the range 0.4 to 1. The construction method of cast-in-place piles combined with compaction grouting for cutting off groundwater is generally proved to be more effective in controlling deformation of deep excavations than diaphragm wall or SMW method.

Key words: soft soil, excavation, cast-in-place pile, diaphragm, SMW method, deformation, settlement

CLC Number:

TU473.2

DING Yong-chun, WANG Jian-hua, XU Zhong-hua, CHEN Jin-jian. Deformation Characteristics of Deep Excavations for Metro Stations in Shanghai Soft Soil Deposits[J]. Journal of Shanghai Jiao Tong University, 2008, 42(11): 1871-1875.

Figures/Tables 9

Tab. 1

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

References 11

[1]	Hsieh P G, Ou C Y.Shape of ground surface settlement profiles caused by excavation[J]. Canadian Geotechnical Journal, 1998, 35(6): 1004-1017.
[2]	Ou C Y, Liao J T, Lin H D.Performance of diaphragm wall constructed using top-down method[J]. Journal of Geotechnical & Geoenvironmental Engineering, 1998, 124(9): 798-808.
[3]	Liu G B, Ng C W W, Wang Z W. Observed performance of a deep multistrutted excavation in Shanghai soft clays[J]. Journal of Geotechnical & Geoenvironmental Engineering, 2005, 131(8): 1004-1013.
[4]	Xu Z H, Wang W D, Wang J H, et al. Performance of deep excavated retaining wall in Shanghai soft deposit[J]. Lowland Technology International, 2005, 7(2): 31-43.
[5]	SZ-08-2000，上海地铁基坑工程施工规程[S].
[6]	Wang Z W, Ng C W W, Liu G B.Characteristics of wall deflections and ground surface settlements in Shanghai[J]. Canadian Geotechnical Journal, 2005, 42(5): 1243-1254.
[7]	徐中华. 上海地区支护结构与主体地下结构相结合的深基坑变形性状研究[D]. 上海: 上海交通大学土木工程系, 2007.
[8]	Ou C Y, Hsieh P G, Chiou D C. Characteristics of ground surface settlement during excavation[J]. Canadian Geotechnical Journal, 1993, 30(5): 798-808.
[9]	Mana A I, Clough G W. Prediction of movements for braced cuts in clay[J]. Journal of the Geotechnical Engineering Division, 1981, 107(6): 759-777.
[10]	Terzaghi K. Theoretical soil mechanics [M]. New York: John Wiley & Sons, 1943.
[11]	侯学渊, 杨敏.软土地基变形控制设计理论和工程实践[M]. 上海: 同济大学出版社, 1996.

工况	日期(2004年)	施工内容
1	10-17	开挖3.2 m～-4.1 m，安装第2道撑
2	10-20	开挖2.9 m～-7.0 m，安装第3道撑
3	10-23	开挖3.0 m～-10.0 m，安装第4道撑并逆作中板
4	11-06	开挖2.9 m～-12.9 m，安装第5道撑
5	11-15	开挖2.9 m～-15.8 m，浇筑垫层
6	11-20	底板浇筑
7	11-24	拆除第5道和第4道撑
8	11-27	施工地下2层结构
9	12-01	拆除第3道和第2道撑
10	12-09	施工地下1层结构
11	12-16	结构封顶，拆除第1道撑

[1]	LI Jianjun, ZHU Wenfeng, SUN Haitao, LI Yuanhui, WANG Shunchao. Method of Curing Deformation Prediction and Surface Reconstruction Compensation for Roller-Hemming Structures with Dissimilar Materials [J]. Journal of Shanghai Jiao Tong University, 2022, 56(7): 965-976.
[2]	YANG Qirun, LI Mingguang, CHEN Jinjian, WU Hang. Interaction Mechanisms of Synchronously Performed Adjacent Excavations [J]. Journal of Shanghai Jiao Tong University, 2022, 56(6): 722-729.
[3]	WU Guanlun, SHI Guanglin. Design and Realization of Continuum Manipulator Based on Coupling of Double Parallel Mechanism [J]. Journal of Shanghai Jiao Tong University, 2022, 56(6): 809-817.
[4]	LIN Zhangpeng, YU Haidong, YUAN Ke. Model of Assembly Deviation of Irregular Large Thin-Walled Structures Based on Higher-Order Composite Shell Element [J]. Journal of Shanghai Jiao Tong University, 2022, 56(5): 584-593.
[5]	LI Zeyao, ZHOU Jie, TIAN Wanjun, PEI Wansheng. Accumulative Plastic Deformation of Saturated Soft Clay Under Variable Frequency Cyclic Loading for Subway [J]. Journal of Shanghai Jiao Tong University, 2022, 56(4): 454-463.
[6]	FENG Guohui, XU Xing, HOU Shilei, FAN Rundong, YANG Kaifang, GUAN Lingxiao, XU Changjie. Deflections of Adjacent Underground Tunnel Induced by Excavation Based on Kerr Foundation Model [J]. Journal of Shanghai Jiao Tong University, 2022, 56(4): 474-485.
[7]	WANG Rongyong, LIU Linqi, WANG Yingyi, HUANG Xingchun. Calculation Method of Pile Foundation Settlement Displacement Based on Virtual Column Equivalent Model [J]. Journal of Shanghai Jiao Tong University, 2021, 55(9): 1126-1133.
[8]	XU Changjie, ZENG Yiting, TIAN Wei, CHEN Ming. Analytical Analysis of Influence of Dewatering on Adjacent Pipelines Based on Pasternak Foundation [J]. Journal of Shanghai Jiao Tong University, 2021, 55(6): 652-662.
[9]	CHEN Shuan, WU Huaina, CHEN Renpeng, SHEN Shuilong, LIU Yuan. Deformation of a Collinear Tunnel Induced by Overlying Long-Distance Excavation [J]. Journal of Shanghai Jiao Tong University, 2021, 55(6): 698-706.
[10]	XIAO Zhaoyun, LI Mingguang, WANG Dafa, CHEN Jinjian. Test and Analysis of Deformation Characteristics of Deep Foundation Pit in Residual Soil Under Rainfall [J]. Journal of Shanghai Jiaotong University, 2020, 54(8): 873-880.
[11]	GAO Yiwen, LI Mingguang, CHEN Jinjian. Stress and Deformation Performance of Deep Excavation with Asymmetrical Retaining Structures in Adjacent Surcharge [J]. Journal of Shanghai Jiaotong University, 2020, 54(6): 643-651.
[12]	CAO Weiwei, LI Mingguang, WU Wei, XIA Xiaohe, SHI Yujin . Safety Evaluation Method for Long-Term Operation of Metro Based on Combination Weighting Method [J]. J Shanghai Jiaotong Univ Sci, 2020, 25(6): 700-705.
[13]	WANG Xianjin, GAO Xu, YU Kuigang . Fixture Locating Modelling and Optimization Research of Aluminum Alloy Sidewall in a High-Speed Train Body [J]. J Shanghai Jiaotong Univ Sci, 2020, 25(6): 706-713.
[14]	NAI Kimsrorng, LI Mingguang, CHEN Jinjian. Effect of Wall Deformation on Dewatering-Induced Ground Surface Settlement [J]. Journal of Shanghai Jiao Tong University(Science), 2020, 25(4): 417-425.
[15]	QU Yang, LUO Yongfeng, ZHU Zhaochen, HUANG Qinglong. Simplified Procedure for Seismic Response Analysis of the Latticed Arch Under Bi-Directional Earthquake Excitations [J]. Journal of Shanghai Jiao Tong University, 2020, 54(4): 387-396.