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。
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.
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
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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参考文献
[1]PECK R B. Deep Excavation and Tunneling in Soft Ground[C]∥Proceedings of the 7th International Conference on Soil Mechanics and Foundation Engineering. Mexico: State-of-the-Art-Volume, 1969: 225-290.
[2] CLOUGH G W, O’ROURKE T D. Construction Induced Movements of in situ Walls[C]∥ASCE. Proceedings of the 1990 Specialty Conference on Design and Performance of Earth Retaining Structures, New York, June 18-21, 1990: 439-470.
[3] OU C Y, HSIEH P G, CHIOU D C. Characteristics of Ground Surface Settlement During Excavation[J]. Canadian Geotechnical Journal, 1993, 30(5): 758-767.
[4] HSIEH P G, OU C Y. Shape of Ground Surface Settlement Profiles Caused by Excavation[J]. Canadian Geotechnical Journal, 1998, 35(6): 1004-1017.
[5] 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.
[6] WANG J H, XU Z H, WANG W D. Wall and Ground Movements Due to Deep Excavations in Shanghai Soft Soils[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2009, 136(7): 985-994.
[7] 王卫东,徐中华,王建华. 上海地区深基坑周边地表变形性状实测统计分析[J]. 岩土工程学报, 2011,33(11):1659-1666.
[8] KUNG G T, JUANG C H, HSIAO E C, et al. Simplified Model for Wall Deflection and Ground-surface Settlement Caused by Braced Excavation in Clays[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2007, 133(6): 731-747
[9]杨 敏,卢俊义. 基坑开挖引起的地面沉降估算[J]. 岩土工程学报,2010,32(12):1821-1828.
[10]OU C Y, HSIEH P G. A Simplified Method for Predicting Ground Settlement Profiles Induced by Excavation in Soft Clay[J]. Computers and Geotechnics, 2011, 38(8): 987-997
[11]尹盛斌,丁红岩. 软土基坑开挖引起的坑外地表沉降预测数值分析[J]. 岩土力学,2012,33(4):1210-1216.
[12]王卫东,王浩然,徐中华. 上海地区板式支护体系基坑变形预测简化计算方法[J]. 岩土工程学报,2012,34(10):1792-1800.
[13]钱建固,王伟奇. 刚性挡墙变位诱发墙后地表沉降的理论解析[J]. 岩石力学与工程学报,2013,32(增刊1): 2698-2703.
[14]顾剑波,钱建固. 任意柔性挡墙变位诱发地表沉降的解析理论预测[J]. 岩土力学,2015,36(增刊1):465-470.
[15]沈路遥,钱建固,张戎泽. 挡墙水平变位诱发地表沉降的简化解析解[J]. 岩土力学,2016,37(8):2293-2298.
[16]BOWLES J E. Foundation Analysis and Design[M]. Beijing: China Architecture & Building Press, 2004:709-711.
[17]刘建航,侯学渊. 基坑工程手册[M].北京:中国建筑工业出版社,1997.
[18]周永胜.多阶段递进式预测模型在基坑变形中的应用研究[J].长江科学院院报,2017,34(8):47-51.
[19]朱 靓.基于MF-DFA分析和PSO-ELM模型的基坑变形规律研究[J].长江科学院院报,2019,36(3):53-58.
[20]王雪妮,韩国锋.地铁车站深基坑的变形预测及稳定性研究[J].长江科学院院报,2018,35(10):77-81,87.
[21]唐孟雄, 赵锡宏. 深基坑周围地表任意点移动变形计算及应用[J]. 同济大学学报(自然科学版), 1996, 24(3): 238-244.
[22]李 鑫,邹豫皖. 软土基坑周围地表沉降估算[J]. 佳木斯大学学报(自然科学版),2014,32(2):202-205.
[23]李小青,王朋团,张 剑. 软土基坑周围地表沉陷变形计算分析[J]. 岩土力学,2007(9):1879-1882.
[24]王 翠. 天津地区地铁深基坑变形及地表沉降研究[D]. 天津:天津大学,2005.
[25]张 彬,张 成. 沈阳地铁车站深基坑沉降变形特性[J]. 辽宁工程技术大学学报(自然科学版), 2015, 34(2): 197-202.
[26]王智勇. 桩锚支护体系的内力和位移分析[D]. 兰州:兰州理工大学,2008.
[27]张尚根,陈志龙,曹继勇. 深基坑周围地表沉降分析[J]. 岩土工程技术, 1999, (4): 7-9.
[28]唐孟雄,陈如桂. 深基坑工程变形控制[M]. 北京:中国建筑工业出版社, 2006: 23-28.
[29]彭振斌, 张可能. 深基坑开挖与支护工程设计计算与施工[M]. 武汉: 中国地质大学出版社, 1997.
[30]FINNO R J, BRYSON S, CALVELLO M. Performance of a Stiff Support System in Soft Clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2002, 128(8): 660-671.
[31]聂宗泉,张尚根,孟少平. 软土深基坑开挖地表沉降评估方法研究[J]. 岩土工程学报,2008, 30(8): 1218-1223.
[32]OU C Y, LIAO J T, LIN H D. Performance of Diaphragm Wall Constructed Using Top-down Method[J]. Journal of Geotechnical and Geoenvironmental Engineering, 1998, 124(9): 798-808.
[33]HSIEH P G, OU C Y. Analysis of Deep Excavations in Clay under the Undrained and Plane Strain Condition with Small Strain Characteristics[J]. Journal of the Chinese Institute of Engineers, 2012, 35(5): 601-616.
[34]CHEN J C. Building Protection Measures During Deep Excavation[R]. Taipei: Architecture and Building Research Institute, 2005.
[35]BURLAND J B, HANCOCK R J R, BURLAND J. Underground Car Park at the House of Commons[M]. London: Building Research Establishment, 1977.
[36]SIMPSON B, O’RIORDAN N J, CROFT D D.A Computer Model for the Analysis of Ground Movements in London Clay[J]. Géotechnique, 1979, 29(2): 149-175.
基金
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)
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