兰溪电厂工程桩竖向承载力的研究
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摘要
在桩基础的设计体系中,解决承载力是一个关键性问题。而沉降特性是确定承载力的重要指标,单桩沉降方面的理论分析方法主要有荷载传递法、弹性理论法、剪切变形传递法、数值分析法、其它经验简化法等五个方面。理论分析方法不如现场原型试验直观和准确,但具有经济、快捷、预测、定量对比的优势,其中荷载传递法是利用桩荷载试验资料进行分析、确定荷载传递函数,依靠其数据运算得到荷载--沉降曲线,由此分析桩的工程力学性能。
本文结合我国目前工程实践和现行规范规定,从浙江兰溪市某典型静荷载实例出发,在深入分析竖向荷载作用下单桩的荷载传递过程、变化规律和荷载-沉降特性之后,依据不同土层呈现出不同应力应变关系,应用桩的侧摩阻力和沉降位移的改进荷载传递模型,计算桩顶沉降分别处于弹性、弹塑性或塑性等不同状态时所对应的桩顶荷载值,推导出桩顶沉降与承载力之间的一系列公式,用以模拟桩--土相互作用机理,从而实现以桩顶沉降量来控制桩的承载力的设想。
利用本文工作方法,只需土的一般物理力学性能指标即可建立实用性较强的荷载传递函数,进而估算单桩的Q-S曲线。当缺乏某地的静荷载试验资料时,利用该法可了解桩基的沉降特性;或在静荷载试验之前预估试桩的极限承载力和加载等级时,可以提供有效的帮助,具有较好的实践价值。
To resolve bearing capacity is the key problem in the pile foundation design system. But the sedimentation property is the important index to confirm the bearing capacity, primary theory analysis methods of single pile are: load transfer approach, elastic theory method, shearing deformation transfer approach, numerical analysis method and other experiential simplified methods i.e. The theory analysis is not intuitionistic and exact than in-situ test, but it is superior to in-situ test in economic, quick, predictable, quantified. To load transfer approach,it is analysised and confirmde the load transfer function through pile load test profile and through the function to get load-sedimentation curve, so to analysis the engineering properties of the pile.
The paper combine our country engineering practice recently and the criterion rules now, beginning from the classic static load instance in lanxi city of zhejiang province, after deeply analysis the load transfer process ,transformation disciplinarian and load-sedimentation properties of the single pile on the vertical load, by the deferent stress-strain relationship presented by the deferent soil strata, applied modified load transfer model of the side friction resistance and sedimentation displacement. Using modified model to calculate the corresponding pile top load quantity when it is in the elastic, elastic-plastic or plastic situation, derive a series formula between the pile top sedimentation and the bearing capacity, using it to simulate the interaction between the pile and soil, thereby to realize the dream to control the pile load bearing by the pile top sedimentation quantity.
Through the theory of the work, the soil average physical mechanic properties is only needed to construct practical load transfer function, further to estimate the Q-S curve of single pile. when the static load test profile in certain place ,using this method to know the sedimentation properties of the pile foundation; or while pro-estimate the limited bearing capacity and load grade before the static test ,it may provide effective help and practice value is better.
本文结合我国目前工程实践和现行规范规定,从浙江兰溪市某典型静荷载实例出发,在深入分析竖向荷载作用下单桩的荷载传递过程、变化规律和荷载-沉降特性之后,依据不同土层呈现出不同应力应变关系,应用桩的侧摩阻力和沉降位移的改进荷载传递模型,计算桩顶沉降分别处于弹性、弹塑性或塑性等不同状态时所对应的桩顶荷载值,推导出桩顶沉降与承载力之间的一系列公式,用以模拟桩--土相互作用机理,从而实现以桩顶沉降量来控制桩的承载力的设想。
利用本文工作方法,只需土的一般物理力学性能指标即可建立实用性较强的荷载传递函数,进而估算单桩的Q-S曲线。当缺乏某地的静荷载试验资料时,利用该法可了解桩基的沉降特性;或在静荷载试验之前预估试桩的极限承载力和加载等级时,可以提供有效的帮助,具有较好的实践价值。
To resolve bearing capacity is the key problem in the pile foundation design system. But the sedimentation property is the important index to confirm the bearing capacity, primary theory analysis methods of single pile are: load transfer approach, elastic theory method, shearing deformation transfer approach, numerical analysis method and other experiential simplified methods i.e. The theory analysis is not intuitionistic and exact than in-situ test, but it is superior to in-situ test in economic, quick, predictable, quantified. To load transfer approach,it is analysised and confirmde the load transfer function through pile load test profile and through the function to get load-sedimentation curve, so to analysis the engineering properties of the pile.
The paper combine our country engineering practice recently and the criterion rules now, beginning from the classic static load instance in lanxi city of zhejiang province, after deeply analysis the load transfer process ,transformation disciplinarian and load-sedimentation properties of the single pile on the vertical load, by the deferent stress-strain relationship presented by the deferent soil strata, applied modified load transfer model of the side friction resistance and sedimentation displacement. Using modified model to calculate the corresponding pile top load quantity when it is in the elastic, elastic-plastic or plastic situation, derive a series formula between the pile top sedimentation and the bearing capacity, using it to simulate the interaction between the pile and soil, thereby to realize the dream to control the pile load bearing by the pile top sedimentation quantity.
Through the theory of the work, the soil average physical mechanic properties is only needed to construct practical load transfer function, further to estimate the Q-S curve of single pile. when the static load test profile in certain place ,using this method to know the sedimentation properties of the pile foundation; or while pro-estimate the limited bearing capacity and load grade before the static test ,it may provide effective help and practice value is better.
引文
[1] 石名磊,龚维明等,基础工程.南京:东南大学出版社,2002:203-209
[2] 沈保汉,桩基础测试勘察设计与施工(二)--桩的垂直静载试验.工业建筑出版社,1990
[3] 沈保汉,桩基础测试勘察设计与施工(三)--桩的极限荷载的确定.工业建筑出版社,1990
[4] 卢世深,林亚超,桩基础的计算和分析.人民交通出版社,1990
[5] 宰金珉,宰金璋,高层建筑基础分析与设计.中国建筑工业出版社,1994
[6] (美)J E Bowles,Foundation Analysis and Design.基础工程分析与设计(唐念慈等译).中国建筑工业出版社,1990
[7] 戴林,P-K 法确定单桩竖向承载力.岩土工程技术,2001,3
[8] 刘锍氚,单桩承载性能的三维有限元无限元藕合分析.岩土力学,2000,3
[9] 曾国熙,叶政青等,桩基工程手册.中国建筑工业出版社,1995
[10] 安关峰,桩(土)与承台组合结钩罚单元分析.岩土工程学报,2000,6
[11] 罗晓晖,用遗传算法确定地基承载力.岩石力学与工程学报,2001,3
[12] 费勤发,分层总和法在单桩分析中的应用.水利水运科学研究,1989,4:59-63
[13] 刘用暖,一种桩--土三维等厚度接触单元及其应用研究.西安理工大学硕士学位论文,2001,3
[14] 张冬雾等,一种土与结构接触面模型的建立和应用.岩土工程学报,1998,6
[15] 陈龙珠,桩轴向荷载沉降曲线的一种解析算法.岩土工程学报,1994,6
[16] 江礼茂,一个以波动理论为基础计算单桩承载力的计算机程序.岩土工程学报,1990,4
[17] 杨挺,人工挖孔桩竖向承载力的分析与研究.建筑结构,1999,12
[18] 浙江大学土木工程测试中心,浙江兰溪发电厂试桩工程静载试验检测报告.2003,12
[19] Seed H B,Reese L C(1957),The action of soft clay along friction Plies [J].Trans.ASCE Vo1.122
[20] Kezdi A(1957),The bearing capacity of pile and pile groups[J].Proc.4th ICSMFE,London,Vol.2
[21] 佐滕悟,基桩承载力机理[J].土木技术,1965,20(1):1-5
[22] Gardner W S , Consideration In the design of drilled Piers[J].Design Construction and Performance of Deep Foundation,1975
[23] Kraft L M,Ray R P and Kagawa T(1981),Theoretical t-z curves[J].Geotechnical Engineering division.ASCE Vo1.107.No.GT11
[24] 陈龙珠,梁国钱,朱金颖等,桩轴向荷载-沉降曲线的一种解析算法[J].岩土工程学报,1994,16(6):30-38
[25] 房卫民,赵明华,苏检来等,由沉降量控制桩竖向极限承载力的分析[J].中南公路工程,1999,24(2):23-25
[26] 秦波,殷红艳,荷载传递函数的选择与应用[J].勘察科学技术,2001,(3):13-16
[27] 何思明,轴向荷载下单桩荷载传递机理[[A].桩基工程设计与施工[C].北京:中国建筑工业出版社,1994:18-22
[28] Coyle H M,Reese L C(1966),Load Transfer for Axially Loaded Piles in Clay[J].Journal of Soil Mechanics and Foundations Division.ASCE Vo1.92,SM2:1-26
[29] 邱钰等,用荷载传递法计算深长大直径嵌岩桩单桩沉降[J].土木工程学报,2001,34(5):72-78
[30] 戴国亮,龚维明,梅国雄等,基于桩土岩共同作用的自平衡法试桩分析方法[J].四川建筑科学研究,2002,28(2):30-32
[31] 郭忠贤,杨志红,宋杰等,夯实水泥土桩的荷载传递特性[J].岩土力学,2000,21(3):284-288
[32] 刘利民,陈有亮,计算复合地基沉降的位移协调法[J].上海大学学报,1996,2(6):608-613
[33] 傅旭东,赵善锐,荷载传递法计算单桩沉降的可靠度[J].工业建筑,2001,31(1):23-26
[34] 钟岱辉,傅传国等,桩与多层地基相互作用分析的增量传递矩阵法[J].工业建筑,1999,29(6):37-41
[35] 田美存,徐永福,荷载传递法在群桩分析中的应用[J].河海大学学报,1997,25(1):62-66
[36] 郭忠贤,杨志红,宋杰等,夯实水泥土桩的荷载传递特性[J].岩土力学,2000,21(3):284-288
[37] Poulos H G,Davis E H,Pile Foundation analysis and design.The University of Sydey,1980
[38] 《桩基工程手册》编写委员会,桩基工程手册[S].北京:中国建筑工业出版社,1997,9-56
[39] 刘金砺,黄强等,竖向荷载下群桩的变形性状及沉降计算[J].岩土工程学报,1995,17(6):1-13
[40] 陈竹昌,王建华,采用弹性理论分析搅拌桩性能的探讨[J].岩土力学,1993,6:31-34
[41] Cooke R W,Price G and Tarr K J(1979),Jacked pile in London clay:a study of load transfer and settlement under working conditions[J].Geotechnique,1979,29(2)
[42] Randolph M F and Wroth C P(1978),Analysis of deformation of vertically loaded piles[J].Geotech.Engng,ASCE Vo1.104.No.GT12
[43] 龚维明,章丛俊,吕志涛,群桩沉降实用计算方法[J].工业建筑,1997,27(1):34-39
[44] Ellison R D(1971),Load-Deformation for.bored Pile[J].Proc.ASCE(SM4) Vo1.97,译文载于《水利水运科技情报》,1978 一增刊 2
[45] Ottavani M,Three-dimensional finite element analysis of vertically loaded pile groups.Geotechnique Vo1.25.No.2,1975
[46] Butterfield R and Banerjee P K(1971),The problem of Pile Group-Pile Cap Interaction[J].Geotechique,21(2):135-142
[47] 杨敏,上部结构与桩筏基础共同作用理论与实验研究(博士学位论文)[D].上海:同济大学,1989
[48] Brisud J L and Tucker L M(1988),Measured and predicted axial response of 98 piles[J].Geotech Engng,ASCE VoI.114 No.GT9
[49] 宰金珉,Mindlin 经典解的近似积分及其精度评价[J].南京建筑工程学院学报,1987(1)
[50] 林天健,熊厚金,王利群,桩基础设计指南[M].北京:中国建筑工业出版社,1999
[51] 王建华,林琼,单桩沉降预估新方法--神经网络法.港口工程,1995(1):25-30,46
[52] 朱百里,沈珠江,计算土力学[M].上海:科学技术出版社,1990,53-92
[53] 刘杰等,考虑桩侧土软化时单桩荷载--沉降关系的解析算法.中国公路学报,2003,4
[54] 刘金砺编,桩基础设计与计算[M].北京:中国建筑工业出版社,1990,21-46
[55] 《地基与基础译文集》(5)桩基础[M].北京:中国建筑工业出版社,1995
[56] 陈明中,龚小南,严平,单桩沉降的一种解析解法[J].水利学报,2000(8):70-74
[57] 龚晓南等,群桩有限元兹单元法.浙江大学学报,2000,4
[58] 郑刚等,水泥搅拌桩有限元无限元藕合分析.天津大学学报,2000,6
[59] 冯紫良,用人工神经网络预测单桩竖向极限承载力.同济大学学报,1999,9
[60] 杨敏等,分层土中的群桩分析法.同济大学学报,1993,2
[61] 刘金砺,桩基工程手册.中国建筑工业出版社,1990
[62] 潘时声,单桩荷载与位移规律分析.清华大学学报,1994,5
[63] 胡汉兵,竖向荷载下群桩承载特性的弹塑性分析.长江科学院院报,2001,1
[64] 傅少君,神经网络方法在桩基础中应用.长江科学院院报,2001,2
[65] 徐萃薇,孙绳武,计算方法引论〔第二版)[M].北京:高等教育出版社,2002,225-246
[66] 刘齐建,大直径桥梁基桩竖向承载力分析及试验研究(硕士学位论文) [D].西安:长安大学,2002,23-29
[67] 罗丽娟,桩土相互作用及单桩承载力确定研究(硕士学位论文)[D].西安:长安大学,2000,34-56
[68] 胡庆立,张克绪,竖向荷载作用下单桩荷载-沉降曲线及土参数研究[J].哈尔滨建筑大学学报,2001,34(4):16-20
[69] 何俊翘,基桩竖向变形与承载力机理研究(硕士学位论文)[J].长沙:湖南大学,2002
[70] 赵明华,曹文贵,刘齐建等,按桩顶沉降控制嵌岩桩承载力的方法[J].岩土工程学报,2004,26(1):67-71
[71] 曹汉志,桩的轴向荷载传递及荷载--沉降曲线的数值计算方法[J] .岩土工程学报,1986,8(6):37-48
[72] 姚泽良,竖向荷载作用下单桩极限承载力计算方法的研究[J].西安:西安理工大学,2003
[73] 刘利民,舒翔等,桩基工程的理论进展与工程实践.中国建材工业出版社,2002
[74] Boulon M,Nova R,Modelling of Soil Structure Interface Ilehavior:A Comparison between Elastoplastic and Rate-Type Laws.Computers and Geotechnics,1990(9):21-46
[75] Chow Y K,Analysis of Vertically Loaded Pile Group.International Journal for Numerical Geomechanics,1986,10:59-72
[2] 沈保汉,桩基础测试勘察设计与施工(二)--桩的垂直静载试验.工业建筑出版社,1990
[3] 沈保汉,桩基础测试勘察设计与施工(三)--桩的极限荷载的确定.工业建筑出版社,1990
[4] 卢世深,林亚超,桩基础的计算和分析.人民交通出版社,1990
[5] 宰金珉,宰金璋,高层建筑基础分析与设计.中国建筑工业出版社,1994
[6] (美)J E Bowles,Foundation Analysis and Design.基础工程分析与设计(唐念慈等译).中国建筑工业出版社,1990
[7] 戴林,P-K 法确定单桩竖向承载力.岩土工程技术,2001,3
[8] 刘锍氚,单桩承载性能的三维有限元无限元藕合分析.岩土力学,2000,3
[9] 曾国熙,叶政青等,桩基工程手册.中国建筑工业出版社,1995
[10] 安关峰,桩(土)与承台组合结钩罚单元分析.岩土工程学报,2000,6
[11] 罗晓晖,用遗传算法确定地基承载力.岩石力学与工程学报,2001,3
[12] 费勤发,分层总和法在单桩分析中的应用.水利水运科学研究,1989,4:59-63
[13] 刘用暖,一种桩--土三维等厚度接触单元及其应用研究.西安理工大学硕士学位论文,2001,3
[14] 张冬雾等,一种土与结构接触面模型的建立和应用.岩土工程学报,1998,6
[15] 陈龙珠,桩轴向荷载沉降曲线的一种解析算法.岩土工程学报,1994,6
[16] 江礼茂,一个以波动理论为基础计算单桩承载力的计算机程序.岩土工程学报,1990,4
[17] 杨挺,人工挖孔桩竖向承载力的分析与研究.建筑结构,1999,12
[18] 浙江大学土木工程测试中心,浙江兰溪发电厂试桩工程静载试验检测报告.2003,12
[19] Seed H B,Reese L C(1957),The action of soft clay along friction Plies [J].Trans.ASCE Vo1.122
[20] Kezdi A(1957),The bearing capacity of pile and pile groups[J].Proc.4th ICSMFE,London,Vol.2
[21] 佐滕悟,基桩承载力机理[J].土木技术,1965,20(1):1-5
[22] Gardner W S , Consideration In the design of drilled Piers[J].Design Construction and Performance of Deep Foundation,1975
[23] Kraft L M,Ray R P and Kagawa T(1981),Theoretical t-z curves[J].Geotechnical Engineering division.ASCE Vo1.107.No.GT11
[24] 陈龙珠,梁国钱,朱金颖等,桩轴向荷载-沉降曲线的一种解析算法[J].岩土工程学报,1994,16(6):30-38
[25] 房卫民,赵明华,苏检来等,由沉降量控制桩竖向极限承载力的分析[J].中南公路工程,1999,24(2):23-25
[26] 秦波,殷红艳,荷载传递函数的选择与应用[J].勘察科学技术,2001,(3):13-16
[27] 何思明,轴向荷载下单桩荷载传递机理[[A].桩基工程设计与施工[C].北京:中国建筑工业出版社,1994:18-22
[28] Coyle H M,Reese L C(1966),Load Transfer for Axially Loaded Piles in Clay[J].Journal of Soil Mechanics and Foundations Division.ASCE Vo1.92,SM2:1-26
[29] 邱钰等,用荷载传递法计算深长大直径嵌岩桩单桩沉降[J].土木工程学报,2001,34(5):72-78
[30] 戴国亮,龚维明,梅国雄等,基于桩土岩共同作用的自平衡法试桩分析方法[J].四川建筑科学研究,2002,28(2):30-32
[31] 郭忠贤,杨志红,宋杰等,夯实水泥土桩的荷载传递特性[J].岩土力学,2000,21(3):284-288
[32] 刘利民,陈有亮,计算复合地基沉降的位移协调法[J].上海大学学报,1996,2(6):608-613
[33] 傅旭东,赵善锐,荷载传递法计算单桩沉降的可靠度[J].工业建筑,2001,31(1):23-26
[34] 钟岱辉,傅传国等,桩与多层地基相互作用分析的增量传递矩阵法[J].工业建筑,1999,29(6):37-41
[35] 田美存,徐永福,荷载传递法在群桩分析中的应用[J].河海大学学报,1997,25(1):62-66
[36] 郭忠贤,杨志红,宋杰等,夯实水泥土桩的荷载传递特性[J].岩土力学,2000,21(3):284-288
[37] Poulos H G,Davis E H,Pile Foundation analysis and design.The University of Sydey,1980
[38] 《桩基工程手册》编写委员会,桩基工程手册[S].北京:中国建筑工业出版社,1997,9-56
[39] 刘金砺,黄强等,竖向荷载下群桩的变形性状及沉降计算[J].岩土工程学报,1995,17(6):1-13
[40] 陈竹昌,王建华,采用弹性理论分析搅拌桩性能的探讨[J].岩土力学,1993,6:31-34
[41] Cooke R W,Price G and Tarr K J(1979),Jacked pile in London clay:a study of load transfer and settlement under working conditions[J].Geotechnique,1979,29(2)
[42] Randolph M F and Wroth C P(1978),Analysis of deformation of vertically loaded piles[J].Geotech.Engng,ASCE Vo1.104.No.GT12
[43] 龚维明,章丛俊,吕志涛,群桩沉降实用计算方法[J].工业建筑,1997,27(1):34-39
[44] Ellison R D(1971),Load-Deformation for.bored Pile[J].Proc.ASCE(SM4) Vo1.97,译文载于《水利水运科技情报》,1978 一增刊 2
[45] Ottavani M,Three-dimensional finite element analysis of vertically loaded pile groups.Geotechnique Vo1.25.No.2,1975
[46] Butterfield R and Banerjee P K(1971),The problem of Pile Group-Pile Cap Interaction[J].Geotechique,21(2):135-142
[47] 杨敏,上部结构与桩筏基础共同作用理论与实验研究(博士学位论文)[D].上海:同济大学,1989
[48] Brisud J L and Tucker L M(1988),Measured and predicted axial response of 98 piles[J].Geotech Engng,ASCE VoI.114 No.GT9
[49] 宰金珉,Mindlin 经典解的近似积分及其精度评价[J].南京建筑工程学院学报,1987(1)
[50] 林天健,熊厚金,王利群,桩基础设计指南[M].北京:中国建筑工业出版社,1999
[51] 王建华,林琼,单桩沉降预估新方法--神经网络法.港口工程,1995(1):25-30,46
[52] 朱百里,沈珠江,计算土力学[M].上海:科学技术出版社,1990,53-92
[53] 刘杰等,考虑桩侧土软化时单桩荷载--沉降关系的解析算法.中国公路学报,2003,4
[54] 刘金砺编,桩基础设计与计算[M].北京:中国建筑工业出版社,1990,21-46
[55] 《地基与基础译文集》(5)桩基础[M].北京:中国建筑工业出版社,1995
[56] 陈明中,龚小南,严平,单桩沉降的一种解析解法[J].水利学报,2000(8):70-74
[57] 龚晓南等,群桩有限元兹单元法.浙江大学学报,2000,4
[58] 郑刚等,水泥搅拌桩有限元无限元藕合分析.天津大学学报,2000,6
[59] 冯紫良,用人工神经网络预测单桩竖向极限承载力.同济大学学报,1999,9
[60] 杨敏等,分层土中的群桩分析法.同济大学学报,1993,2
[61] 刘金砺,桩基工程手册.中国建筑工业出版社,1990
[62] 潘时声,单桩荷载与位移规律分析.清华大学学报,1994,5
[63] 胡汉兵,竖向荷载下群桩承载特性的弹塑性分析.长江科学院院报,2001,1
[64] 傅少君,神经网络方法在桩基础中应用.长江科学院院报,2001,2
[65] 徐萃薇,孙绳武,计算方法引论〔第二版)[M].北京:高等教育出版社,2002,225-246
[66] 刘齐建,大直径桥梁基桩竖向承载力分析及试验研究(硕士学位论文) [D].西安:长安大学,2002,23-29
[67] 罗丽娟,桩土相互作用及单桩承载力确定研究(硕士学位论文)[D].西安:长安大学,2000,34-56
[68] 胡庆立,张克绪,竖向荷载作用下单桩荷载-沉降曲线及土参数研究[J].哈尔滨建筑大学学报,2001,34(4):16-20
[69] 何俊翘,基桩竖向变形与承载力机理研究(硕士学位论文)[J].长沙:湖南大学,2002
[70] 赵明华,曹文贵,刘齐建等,按桩顶沉降控制嵌岩桩承载力的方法[J].岩土工程学报,2004,26(1):67-71
[71] 曹汉志,桩的轴向荷载传递及荷载--沉降曲线的数值计算方法[J] .岩土工程学报,1986,8(6):37-48
[72] 姚泽良,竖向荷载作用下单桩极限承载力计算方法的研究[J].西安:西安理工大学,2003
[73] 刘利民,舒翔等,桩基工程的理论进展与工程实践.中国建材工业出版社,2002
[74] Boulon M,Nova R,Modelling of Soil Structure Interface Ilehavior:A Comparison between Elastoplastic and Rate-Type Laws.Computers and Geotechnics,1990(9):21-46
[75] Chow Y K,Analysis of Vertically Loaded Pile Group.International Journal for Numerical Geomechanics,1986,10:59-72