一种黏土层中深基坑开挖地表沉降预测方法
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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x_m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x_0,推导地表沉降曲线包络面积A_v;最后,根据地表沉降面积A_v与围护结构侧移面积A_h之间的相关性,计算地表沉降最大值δ_(max),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。
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 x_m of maximum settlement(which is defined as the distance x_m 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 x_0 based on the aforementioned assumed function of ground settlement in association with soil loss theory. Furthermore, we derived the area A_v enveloped by the ground settlement curve, and in the meantime obtained the maximum ground settlement δ_(max) according to the relation between A_v and A_h, 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 δ_(max) 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.
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 x_m of maximum settlement(which is defined as the distance x_m 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 x_0 based on the aforementioned assumed function of ground settlement in association with soil loss theory. Furthermore, we derived the area A_v enveloped by the ground settlement curve, and in the meantime obtained the maximum ground settlement δ_(max) according to the relation between A_v and A_h, 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 δ_(max) 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.
引文
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[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.
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[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.
[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.