FIELD MEASUREMENT AND ANALYSIS FOR INFLUENCE OF CONCRETE CUSHION AND CONCRETE SHRINKAGE OF HORIZONTAL STRUCTURE ON DEFORMATION OF RETAINING WALL
WANG Xujun1,GONG Jian1,2,ZHAO Xihong3
(1. Department of Building Engineering,Tongji University,Shanghai 200092,China;2. Shanghai Construction Group,Shanghai 200080,China;3. Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China)
Abstract:Based on field measured data,the lateral deformation laws of retaining wall,which belongs to super-large deep foundation pit of Shanghai Tower podium,are analyzed. The analytical results show that,during the period from completion of cushion concrete placement to the completion of beam-slab concrete placement,the increment in lateral deformation of retaining wall is very small,indicating that the constraint effect of cushion on deformation of retaining wall is significant. However,due to the eccentric load effect,the lateral deformation of circle wall,which is the support point of cushion,is relatively large;and it leads to a large increment in lateral deformation of measuring point P04 during this period. Combining with the site construction conditions,the constraint effect of cushion concrete is explained. During the period of structure concrete curing,due to the concrete shrinkage of overlong beam-slab structure or bottom plate,the increment in lateral displacement of retaining wall is large. During the curing period of bottom plate,the increment in lateral deformation of measuring point P23 is larger than that caused by soil excavation for the last time. For the short concrete structure,the effect of concrete shrinkage on the lateral displacement of retaining wall can be neglected. Finally,based on the above laws,some suggestions are proposed to control the deformation of retaining wall effectively.
王旭军1,龚 剑1,2,赵锡宏3. 混凝土垫层及水平结构混凝土收缩对围护墙变形影响的实测分析[J]. 岩石力学与工程学报, 2013, 32(3): 520-527.
WANG Xujun1,GONG Jian1,2,ZHAO Xihong3. FIELD MEASUREMENT AND ANALYSIS FOR INFLUENCE OF CONCRETE CUSHION AND CONCRETE SHRINKAGE OF HORIZONTAL STRUCTURE ON DEFORMATION OF RETAINING WALL. , 2013, 32(3): 520-527.
[1] 刘建航,侯学渊. 基坑工程手册[M]. 北京:中国建筑工业出版社,1997:3–4.(LIU Jianhang,HOU Xueyuan. Excavation engineering handbook[M]. Beijing:China Architecture and Building Press,1997:3–4.(in Chinese))
[2] 卢礼顺,刘建航,刘国彬. 基坑底混凝土垫层的支撑效应分析[J]. 地下空间,2004,24(6):224–228.(LU Lishun,LIU Jianhang,LIU Guobin. Analysis of supporting effect of concrete base of foundation pit[J]. Underground Space,2004,24(6):224–228.(in Chinese))
[3] 刘国彬,刘登攀,刘丽雯,等. 基坑坑底施工阶段围护墙变形监测分析[J]. 岩石力学与工程学报,2007,26(增2):4 386–4 394.(LIU Guobin,LIU Dengpan,LIU Liwen,et al. Monitoring and analysis of lateral deformation of retaining wall during bottom excavation in deep pit[J]. Chinese Journal of Rock Mechanics and Engineering,2007,26(Supp.2):4 386–4 394.(in Chinese))
[4] WHITTLE A J,HASHASH Y M A,WHITMAN R V. Analysis of a deep excavation in Boston[J]. Journal of Geotechnical Engineering,1993,119(1):69–90.
[5] KUNG G T C. Comparison of excavation-induced wall deflection using top-down and bottom-up construction methods in Taipei silty clay[J]. Computers and Geotechnics,2009,36(3):373–385.
[6] LI L. Shrinkage induced tension in reinforced concrete struts for retaining large-scale excavation[J]. Advanced Materials Research,2011,368–373:2 880–2 886.
[7] 赵锡宏,龚 剑,陈志明. 上海的特深特大基坑工程设计与实践[J]. 岩土工程学报,1999,21(1):104–107.(ZHAO Xihong,GONG Jian,CHEN Zhiming. Design and practice on engineering projects of specially deep and big excavation in Shanghai[J]. Chinese Journal of Geotechnical Engineering,1999,21(1):104–107.(in Chinese))
[8] NG C W W. Observed performance of multipropped excavation in stiff clay[J]. Journal of Geotechnical and Geoenvironmental Engineering,1998,124(9):889–905.
[9] 黄国兴,惠荣炎. 混凝土的收缩[M]. 北京:中国铁道出版社,1990:47–48.(HUANG Guoxing,HUI Rongyan. Concrete shrinkage[M]. Beijing:China Railway Publishing House,1990:47–48.(in Chinese))
[10] 王旭军. 上海中心大厦裙房的深大基坑工程围护墙变形分析[J]. 岩石力学与工程学报,2012,31(2):421–430.(WANG Xujun. Analysis of retaining wall deformation for deep and big excavation engineering of podium in Shanghai Tower[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(2):421–430.(in Chinese))