上部土钉墙下部桩锚（撑）复合支护结构工作机理研究
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摘要
伴随着我国经济的迅猛发展,人们也对基坑支护结构提出了越来越高的要求,传统的支护结构己不能很好的满足这种要求。上部土钉墙下部桩锚(撑)复合支护结构兼顾了桩锚支护结构和桩撑支护结构各自的优点,取得了扬长避短的效果。然而针对这种复合支护结构的相关研究明显落后于工程需求。
结合郑州市兰德国际中心深基坑工程,在基坑开挖过程中,对基坑周边及支护结构主要部位的位移进行现场监测并分析监测数据,概述上部土钉墙下部桩锚(撑)复合支护结构支护下深基坑位移的发展规律；采用ABAQUS软件对整个基坑开挖过程进行模拟分析,并与实测数据进行对比,验证模型及参数的合理性和适用性；通过变化设计参数进行虚拟设计,总结各设计参数对基坑及支护结构位移变化的影响。主要得到了以下结论：
(1)上部土钉墙下部桩锚(撑)复合支护结构应用于郑州地区该类土层时,土钉墙部分的高度以3.6m为宜,且不宜超过6m。
(2)支护结构选型时需要确保排桩冠梁的标高高于附近需要保护建筑物的基础底面。
(3)下部桩锚(撑)支护体系对上部土体的支护效应不明显,上部土钉墙的设计应立足于自身的强度和稳定性设计。
(4)上部土钉墙下部桩锚(撑)复合支护结构中排桩的深层水平位移曲线大体呈现“P”字形状,且最大位移出现在钢筋混凝土内支撑位置附近。
(5)在当场地条件对基坑变形控制要求比较严格时,有必要在支护桩高度(基底以上)上部的1/3区间内设置内支撑；当基坑深度较大时,深部支护结构承受的主动土压力较大,应在该范围内增设内支撑。
With the rapid development of economy in our country, people also put forward higher requirements for foundation pit supporting structures, the traditional supporting structures cannot meet this requirement very well. The upper soil nailing wall and lower anchor pile (bracing) composite supporting structure takes account of the advantages both of the pile anchor supporting structure and inside supporting structures. Not only can it enhance advantages but also circumvent weaknesses. Yet the related researches on this composite retaining structure obviously lag behind the demand of the engineering.
This paper bases on the deep foundation pit engineering of the rand international center in Zhengzhou. The displacement of the surrounding foundation pit and main parts of the supporting structures has been monitored in site during the process of excavation of foundation pit; the monitoring data has been analyzed. The law of displacement of the foundation pit with supporting of the upper soil nailing wall and lower anchor pile (bracing) composite supporting structure has been summarized. ABAQUS has been used to simulate the whole process of excavation, the model and parameters shows rational and applicable according to the comparison between simulation result and monitoring data. The influence from design parameters on displacement of foundation pit and supporting has been summarized by changing design parameters for the virtual design. The paper mainly got the following conclusions:
(1) It will be better if the height of the soil nailing wall is between three to six meters when the composite supporting structure is used in this type of soil in Zhengzhou, and it should not more than6meters.
(2) Should ensure that the beam elevation is higher than the bottom of the surrounding foundations where the upper buildings need to be protected during the process of choosing supporting structures.
(3) The under supporting system of pile anchor (bracing) do little to the stability of the upper soil, and the design of the upper soil nail wall should be done based on its own strength and stability.
(4) The deep horizontal displacement curve of piles in the composite supporting structure of upper soil nailing wall and lower anchor pile (bracing) is generally presents the "P" shape, at the same time, the maximal displacement appears near the reinforced concrete brace position.
(5) It is necessary to set up interior bracings in the interval of upper one-third of the piles if the restriction of deformation is strict. For the deep excavation, inner bracing should be added where the active earth pressure of the under supporting structure is large.
结合郑州市兰德国际中心深基坑工程,在基坑开挖过程中,对基坑周边及支护结构主要部位的位移进行现场监测并分析监测数据,概述上部土钉墙下部桩锚(撑)复合支护结构支护下深基坑位移的发展规律；采用ABAQUS软件对整个基坑开挖过程进行模拟分析,并与实测数据进行对比,验证模型及参数的合理性和适用性；通过变化设计参数进行虚拟设计,总结各设计参数对基坑及支护结构位移变化的影响。主要得到了以下结论：
(1)上部土钉墙下部桩锚(撑)复合支护结构应用于郑州地区该类土层时,土钉墙部分的高度以3.6m为宜,且不宜超过6m。
(2)支护结构选型时需要确保排桩冠梁的标高高于附近需要保护建筑物的基础底面。
(3)下部桩锚(撑)支护体系对上部土体的支护效应不明显,上部土钉墙的设计应立足于自身的强度和稳定性设计。
(4)上部土钉墙下部桩锚(撑)复合支护结构中排桩的深层水平位移曲线大体呈现“P”字形状,且最大位移出现在钢筋混凝土内支撑位置附近。
(5)在当场地条件对基坑变形控制要求比较严格时,有必要在支护桩高度(基底以上)上部的1/3区间内设置内支撑；当基坑深度较大时,深部支护结构承受的主动土压力较大,应在该范围内增设内支撑。
With the rapid development of economy in our country, people also put forward higher requirements for foundation pit supporting structures, the traditional supporting structures cannot meet this requirement very well. The upper soil nailing wall and lower anchor pile (bracing) composite supporting structure takes account of the advantages both of the pile anchor supporting structure and inside supporting structures. Not only can it enhance advantages but also circumvent weaknesses. Yet the related researches on this composite retaining structure obviously lag behind the demand of the engineering.
This paper bases on the deep foundation pit engineering of the rand international center in Zhengzhou. The displacement of the surrounding foundation pit and main parts of the supporting structures has been monitored in site during the process of excavation of foundation pit; the monitoring data has been analyzed. The law of displacement of the foundation pit with supporting of the upper soil nailing wall and lower anchor pile (bracing) composite supporting structure has been summarized. ABAQUS has been used to simulate the whole process of excavation, the model and parameters shows rational and applicable according to the comparison between simulation result and monitoring data. The influence from design parameters on displacement of foundation pit and supporting has been summarized by changing design parameters for the virtual design. The paper mainly got the following conclusions:
(1) It will be better if the height of the soil nailing wall is between three to six meters when the composite supporting structure is used in this type of soil in Zhengzhou, and it should not more than6meters.
(2) Should ensure that the beam elevation is higher than the bottom of the surrounding foundations where the upper buildings need to be protected during the process of choosing supporting structures.
(3) The under supporting system of pile anchor (bracing) do little to the stability of the upper soil, and the design of the upper soil nail wall should be done based on its own strength and stability.
(4) The deep horizontal displacement curve of piles in the composite supporting structure of upper soil nailing wall and lower anchor pile (bracing) is generally presents the "P" shape, at the same time, the maximal displacement appears near the reinforced concrete brace position.
(5) It is necessary to set up interior bracings in the interval of upper one-third of the piles if the restriction of deformation is strict. For the deep excavation, inner bracing should be added where the active earth pressure of the under supporting structure is large.
引文
[1]余志成,施文华.深基坑支护设计与施工[M].北京,中国建筑工业出版社,1997
[2]侯学渊,刘国彬,黄院雄.城市基坑工程发展的几点看法[J].施工技术,2000,29(1)：57
[3]宋二祥,方东平.软土地基深基坑支护变形分析[J].隧道及地下工程,1997,18(3)：1-2
[4]汪成.复合土钉墙的承载机理和变形分析[D].[硕士学位论文].陕西：西安建筑科技大学,2003
[5]黄云.复合土钉墙中的侧向土压力研究[D].[硕士学位论文].湖北：武汉理工大学,2003
[6]魏有龙.复合土钉墙的水平位移分析与预测[D].[硕士学位论文].浙江：浙江大学,2006
[7]蔡斌.土钉墙的屈服准则与有限元分析[D].[硕士学位论文].湖南：湖南大学,2007
[8]潘泓,周陈发,曹洪.复合土钉墙的角部空间效应及变形性状分析[J].岩土力学,2008.29(2)：333-336
[9]魏焕卫,杨敏,孙剑平等.土钉墙变形规律及其相关性的实测研究[J].岩土力学,2006.30(6)：1753～1758
[10]王立峰.土钉墙面层土压力的计算分析[J].岩土力学,2010,31(5)：1615-1620
[11]何江飞.土钉墙支护结构的作用机理及面层受力分析研究[D].[硕士学位论文].甘肃：兰州理工大学,2010
[12]杨育文.土钉墙中土压力探究[J].地下空间与工程学报,2010,6(2)：300-305
[13]俞建霖,何萌,张文龙等.土钉墙支护极限高度的有限元分析与拟合[J].中南大学学报(自然科学版),2011,42(5)：1447-1453
[14]平杨,白世伟,曹俊坚.深基双排桩空间协同计算理论及位移反分析[J].土木工程学报,2001,34(2)：83
[15]曲力群.不同刚度圈梁对排桩支护结构力学性状的影响[D].[硕士学位论文].四川：西南交通大学,2002
[16]钱尧锋.土钉—排桩复合支护结构的软土主动土压力分析[J].岩石力学与工程学报,2004,23(15)：2655-2658
[17]屠毓敏,王建江.邻近堆载作用下排桩负摩阻力特性研究[J].岩土力学,2007,28(12)：2652-2656
[18]崔允亮.水平荷载作用下排桩的受力和变形特性研究[D].[硕士学位论文].江苏：扬州大学,2009
[19]王盼,陈健.上部土钉与下部排桩组合支护结构的力学性状分析[J].水运工程,2010,10.141～144
[20]杨敏,刘斌.疏排桩—土钉墙组合支护结构工作机理[J].水运工程,2011,32(2)：126～133
[21]张金民,曾进群.桩锚挡墙支护体系挡板土压力的试验研究[J].地下空间,2002,22(1)：58-64
[22]王立明,郭院成,周同和.考虑开挖反弹的桩锚结构土压力计算方法研究[J].郑州大学学报(工学版),2005,26(2)：76-80
[23]吴忠诚,杨志银,罗小满等.疏排桩锚—土钉墙组合支护结构稳定性分析[J].岩石力学与工程学报,2006,25(2)
[24]刘焕斌,晏鄂川,吴益平等.桩锚结构预应力的变形协调确定方法[J].岩土力学,2007,28增刊：891～894
[25]朱剑锋,徐日庆.考虑时效和土拱效应桩—锚基坑土压力计算方法[J].浙江大学学报(工学版),2009,43(4)：767-770
[26]江建红.基于桩锚支护结构的基坑周围地表沉降变形分析[D].[硕士学位论文].北京：北京交通大学,2011
[27]韩国栋.深基坑桩锚支护结构的现场试验研究及数值模拟[D].[硕士学位论文].吉林：吉林大学,2012
[28]马海龙,唐志军,石墩敦.桩锚直径等对水泥土桩锚墙支护影响[J].岩土力学,2012,33(12)：3709-3714
[29]张显飞.深基坑内支撑支护体系及其数值研究[D].[硕士学位论文].浙江：西安建筑科技大学,2006
[30]刘小丽,陈芳,贾永刚.深基坑内支撑等效刚度数值计算影响因素分析[J].中国海洋大学学报,2009,39(2)：275～280
[31]周玲.深基坑内支撑支护结构上的土压力分布研究[D].[硕士学位论文].浙江：浙江工业大学,2009
[32]翟永亮.地铁车站基坑桩撑支护体系m法设计参数研究[D].[硕士学位论文].河南：郑州大学,2010
[33]雍毅.内支撑位置优化在城际轨道深基坑施工中的应用[J].公路,2011,7：30～34
[34]刘红军,孙玺,姜德鸿.“二元”基坑中内支撑支护结构的三维数值分析与监测[J].中国海洋大学学报,2012,42(9)：77-83
[35]常红,张越.竖向承载地下连续墙的沉降计算[J].中国公路学报,2003,16(3)：73-76
[36]李二兵,谭跃虎,张尚根等.深基坑围护中地下连续墙变形的解析计算[J].解放军理工大学学报(自然科学版),2004,5(2)：57～60
[37]徐中华,王建华,王卫东.上海地区深基坑工程中地下连续墙的变形性状[J].土木工程学报,2008,41(8)：81-86
[38]姜忻良,徐炳伟.狭长基坑中地下连续墙的简化计算模型[J].工程力学,2009,26(I)：33-36
[39]张辉,熊巨华,曾英俊.长条形基坑底下连续墙侧向位移数值模拟及其影响因素分析[J].结构工程师,2010,26(1)：80～85
[40]Clough G.W., and Duncan J.M.. Finite element analyses of retaining wall behavior[J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1971,97(12):1657-1673
[41]Clough G.W., and Tsui Y.. Performance of tied-back walls in clay [J]. Journal of the Geotechnical Engineering Division, ASCE,1974,100(12):1259～1273
[42]Clough G.W., and Denby G.M.. Stabilizing berm design for temporary walls in clay [J]. Journal of the Geotechnical Engineering Division,ASCE,1977,103(2):75-90
[43]Clough G.W., and Hansen L.A.. Clay anisotropy and braced wall behavior. Journal of Geotechnical engineering, ASCE,1981,107(7):893-913
[44]Roboski J.F.. Three-dimensional performance and analyses of deep excavations[D]. [PhD thesis]. Northwestern University, Evaston,Illinois,2004
[45]Clark B.G, and Wroth C.P.. Analysis of Duton Green retaining wall based on result of pressuremeter tests [J]. Geotechnique,1984,34(4):549～561
[46]Ou C.Y., Hsieh P.G, and Chiou D.C.. Characteristics of ground surface settlement during excavation [J]. Canadian Geotechnical Journal,1993,30(5):758～767
[47]Ou C.Y., and Lai C.H.. Finite element analysis of deep excavation in layered sandy and clayey soil deposits [J]. Canadian Geotechnical Journal,1993,30(5):758～767
[48]Ou C.Y., Chiou D.C., and Wu T.S.. Three-dimensional finite element analysis of deep excavations [J]. Journal of Geotechnical Engineering, ASCE,1996,122(5):337-345
[49]Ou C.Y., Wu T.S., and Hsieh H.S.. Analysis of deep excavation with column type of ground improvement in soft clay [J]. Journal of Geotechnical Engineering, ASCE,1996s122(9):709～716
[50]Ou C.Y., and ShiauB.Y. Analysis of the corner effect on excavation behaviors [J]. Canadian Geotechnical Journal,1998,35(3):532～540
[51]Ou C.Y., Shiau B.Y., and Wang I.W.. Three-dimensional deformation behavior of the Taipei National Enterprise Center(TNEC) excavation case history [J]. Canadian Geotechnical Journal,2000,37(2):439～445
[52]费康,张建伟ABAQUS在岩土工程中的应用[M].北京：中国水利水电出版社,2010.89-97
[2]侯学渊,刘国彬,黄院雄.城市基坑工程发展的几点看法[J].施工技术,2000,29(1)：57
[3]宋二祥,方东平.软土地基深基坑支护变形分析[J].隧道及地下工程,1997,18(3)：1-2
[4]汪成.复合土钉墙的承载机理和变形分析[D].[硕士学位论文].陕西：西安建筑科技大学,2003
[5]黄云.复合土钉墙中的侧向土压力研究[D].[硕士学位论文].湖北：武汉理工大学,2003
[6]魏有龙.复合土钉墙的水平位移分析与预测[D].[硕士学位论文].浙江：浙江大学,2006
[7]蔡斌.土钉墙的屈服准则与有限元分析[D].[硕士学位论文].湖南：湖南大学,2007
[8]潘泓,周陈发,曹洪.复合土钉墙的角部空间效应及变形性状分析[J].岩土力学,2008.29(2)：333-336
[9]魏焕卫,杨敏,孙剑平等.土钉墙变形规律及其相关性的实测研究[J].岩土力学,2006.30(6)：1753～1758
[10]王立峰.土钉墙面层土压力的计算分析[J].岩土力学,2010,31(5)：1615-1620
[11]何江飞.土钉墙支护结构的作用机理及面层受力分析研究[D].[硕士学位论文].甘肃：兰州理工大学,2010
[12]杨育文.土钉墙中土压力探究[J].地下空间与工程学报,2010,6(2)：300-305
[13]俞建霖,何萌,张文龙等.土钉墙支护极限高度的有限元分析与拟合[J].中南大学学报(自然科学版),2011,42(5)：1447-1453
[14]平杨,白世伟,曹俊坚.深基双排桩空间协同计算理论及位移反分析[J].土木工程学报,2001,34(2)：83
[15]曲力群.不同刚度圈梁对排桩支护结构力学性状的影响[D].[硕士学位论文].四川：西南交通大学,2002
[16]钱尧锋.土钉—排桩复合支护结构的软土主动土压力分析[J].岩石力学与工程学报,2004,23(15)：2655-2658
[17]屠毓敏,王建江.邻近堆载作用下排桩负摩阻力特性研究[J].岩土力学,2007,28(12)：2652-2656
[18]崔允亮.水平荷载作用下排桩的受力和变形特性研究[D].[硕士学位论文].江苏：扬州大学,2009
[19]王盼,陈健.上部土钉与下部排桩组合支护结构的力学性状分析[J].水运工程,2010,10.141～144
[20]杨敏,刘斌.疏排桩—土钉墙组合支护结构工作机理[J].水运工程,2011,32(2)：126～133
[21]张金民,曾进群.桩锚挡墙支护体系挡板土压力的试验研究[J].地下空间,2002,22(1)：58-64
[22]王立明,郭院成,周同和.考虑开挖反弹的桩锚结构土压力计算方法研究[J].郑州大学学报(工学版),2005,26(2)：76-80
[23]吴忠诚,杨志银,罗小满等.疏排桩锚—土钉墙组合支护结构稳定性分析[J].岩石力学与工程学报,2006,25(2)
[24]刘焕斌,晏鄂川,吴益平等.桩锚结构预应力的变形协调确定方法[J].岩土力学,2007,28增刊：891～894
[25]朱剑锋,徐日庆.考虑时效和土拱效应桩—锚基坑土压力计算方法[J].浙江大学学报(工学版),2009,43(4)：767-770
[26]江建红.基于桩锚支护结构的基坑周围地表沉降变形分析[D].[硕士学位论文].北京：北京交通大学,2011
[27]韩国栋.深基坑桩锚支护结构的现场试验研究及数值模拟[D].[硕士学位论文].吉林：吉林大学,2012
[28]马海龙,唐志军,石墩敦.桩锚直径等对水泥土桩锚墙支护影响[J].岩土力学,2012,33(12)：3709-3714
[29]张显飞.深基坑内支撑支护体系及其数值研究[D].[硕士学位论文].浙江：西安建筑科技大学,2006
[30]刘小丽,陈芳,贾永刚.深基坑内支撑等效刚度数值计算影响因素分析[J].中国海洋大学学报,2009,39(2)：275～280
[31]周玲.深基坑内支撑支护结构上的土压力分布研究[D].[硕士学位论文].浙江：浙江工业大学,2009
[32]翟永亮.地铁车站基坑桩撑支护体系m法设计参数研究[D].[硕士学位论文].河南：郑州大学,2010
[33]雍毅.内支撑位置优化在城际轨道深基坑施工中的应用[J].公路,2011,7：30～34
[34]刘红军,孙玺,姜德鸿.“二元”基坑中内支撑支护结构的三维数值分析与监测[J].中国海洋大学学报,2012,42(9)：77-83
[35]常红,张越.竖向承载地下连续墙的沉降计算[J].中国公路学报,2003,16(3)：73-76
[36]李二兵,谭跃虎,张尚根等.深基坑围护中地下连续墙变形的解析计算[J].解放军理工大学学报(自然科学版),2004,5(2)：57～60
[37]徐中华,王建华,王卫东.上海地区深基坑工程中地下连续墙的变形性状[J].土木工程学报,2008,41(8)：81-86
[38]姜忻良,徐炳伟.狭长基坑中地下连续墙的简化计算模型[J].工程力学,2009,26(I)：33-36
[39]张辉,熊巨华,曾英俊.长条形基坑底下连续墙侧向位移数值模拟及其影响因素分析[J].结构工程师,2010,26(1)：80～85
[40]Clough G.W., and Duncan J.M.. Finite element analyses of retaining wall behavior[J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1971,97(12):1657-1673
[41]Clough G.W., and Tsui Y.. Performance of tied-back walls in clay [J]. Journal of the Geotechnical Engineering Division, ASCE,1974,100(12):1259～1273
[42]Clough G.W., and Denby G.M.. Stabilizing berm design for temporary walls in clay [J]. Journal of the Geotechnical Engineering Division,ASCE,1977,103(2):75-90
[43]Clough G.W., and Hansen L.A.. Clay anisotropy and braced wall behavior. Journal of Geotechnical engineering, ASCE,1981,107(7):893-913
[44]Roboski J.F.. Three-dimensional performance and analyses of deep excavations[D]. [PhD thesis]. Northwestern University, Evaston,Illinois,2004
[45]Clark B.G, and Wroth C.P.. Analysis of Duton Green retaining wall based on result of pressuremeter tests [J]. Geotechnique,1984,34(4):549～561
[46]Ou C.Y., Hsieh P.G, and Chiou D.C.. Characteristics of ground surface settlement during excavation [J]. Canadian Geotechnical Journal,1993,30(5):758～767
[47]Ou C.Y., and Lai C.H.. Finite element analysis of deep excavation in layered sandy and clayey soil deposits [J]. Canadian Geotechnical Journal,1993,30(5):758～767
[48]Ou C.Y., Chiou D.C., and Wu T.S.. Three-dimensional finite element analysis of deep excavations [J]. Journal of Geotechnical Engineering, ASCE,1996,122(5):337-345
[49]Ou C.Y., Wu T.S., and Hsieh H.S.. Analysis of deep excavation with column type of ground improvement in soft clay [J]. Journal of Geotechnical Engineering, ASCE,1996s122(9):709～716
[50]Ou C.Y., and ShiauB.Y. Analysis of the corner effect on excavation behaviors [J]. Canadian Geotechnical Journal,1998,35(3):532～540
[51]Ou C.Y., Shiau B.Y., and Wang I.W.. Three-dimensional deformation behavior of the Taipei National Enterprise Center(TNEC) excavation case history [J]. Canadian Geotechnical Journal,2000,37(2):439～445
[52]费康,张建伟ABAQUS在岩土工程中的应用[M].北京：中国水利水电出版社,2010.89-97