桩共振频率与桩周土阻尼系数关系分析
摘要
桩是岩土工程中最常见的基础形式。由于桩基系隐蔽工程,对桩基进行测试以确定其承载力和完整性一直是工程界十分关心的问题。检测桩的完整性一般用动荷载。
低应变动力测桩法,其前提是建立在关于桩的振动频率理论或者应力波在桩的传播理论。低应变动力测桩法因其测量周期短、耗资小、应用简便,目前已被广泛应用于检测桩身完整性的检测。但由于其理论模型与实际情况的差异,工程实践中,因有关桩周土阻尼等系数的采用不仅仍需依赖于静荷载验桩,且与桩基类型、地质条件有关,而导致因测试人员经验不同得出的结论不同而影响到测试的有效性和可信度。
本文系基于桩的振动理论,利用桩的振动频率与桩长的关系,通过对比直接确定桩基断裂的位置,计算过程中避免了桩周土阻尼等不确定因素对计算结果的影响。该方法简单易行,并且通过对一个工程实例的计算说明了其有效性。
Pile is a prevailing mode of foundation in geotechnical engineering. The pile foundation is the concealed work, so to assess pile load capacity and to assess pile integrity has always been of concern. Dynamic load testing is used to assess pile integrity .
The foundation of the theory of Low Strain Integrity Test is wave equation analysis and theory of pile vibration. Due to its simplicity, speed of execution and low cost, Low Strain Integrity Test has been widely applied in pile integrity test. However, due to the differences between theoretical model and actual practices, in engineering practice, the adoption of the soil damping coefficient around the pile not only still has to rely on the pile static loading test , but also on geological conditions and pile type. And the pile test results, due to testing personnel experience vary,affecting the validity and reliability of the test method.
This paper is based on the vibration theory of pile,applying the rationale between frequency of vibration of pile and pile length, to determine the broken place of the pile. With noregard to the damping coefficient around the pile, the method is simple and its effectiveness has been confirmed by a practical engineering case.
低应变动力测桩法,其前提是建立在关于桩的振动频率理论或者应力波在桩的传播理论。低应变动力测桩法因其测量周期短、耗资小、应用简便,目前已被广泛应用于检测桩身完整性的检测。但由于其理论模型与实际情况的差异,工程实践中,因有关桩周土阻尼等系数的采用不仅仍需依赖于静荷载验桩,且与桩基类型、地质条件有关,而导致因测试人员经验不同得出的结论不同而影响到测试的有效性和可信度。
本文系基于桩的振动理论,利用桩的振动频率与桩长的关系,通过对比直接确定桩基断裂的位置,计算过程中避免了桩周土阻尼等不确定因素对计算结果的影响。该方法简单易行,并且通过对一个工程实例的计算说明了其有效性。
Pile is a prevailing mode of foundation in geotechnical engineering. The pile foundation is the concealed work, so to assess pile load capacity and to assess pile integrity has always been of concern. Dynamic load testing is used to assess pile integrity .
The foundation of the theory of Low Strain Integrity Test is wave equation analysis and theory of pile vibration. Due to its simplicity, speed of execution and low cost, Low Strain Integrity Test has been widely applied in pile integrity test. However, due to the differences between theoretical model and actual practices, in engineering practice, the adoption of the soil damping coefficient around the pile not only still has to rely on the pile static loading test , but also on geological conditions and pile type. And the pile test results, due to testing personnel experience vary,affecting the validity and reliability of the test method.
This paper is based on the vibration theory of pile,applying the rationale between frequency of vibration of pile and pile length, to determine the broken place of the pile. With noregard to the damping coefficient around the pile, the method is simple and its effectiveness has been confirmed by a practical engineering case.
引文
[1].陈凡等编著,基桩质量检测技术,中国建筑工业出版社,2003
[2].国家标准《建筑地基基础设计规范》GB50007-2002
[3]. Koten H Van, Middendorp P, Brederode P Van:An Analysis of Dissipative Wave Propagation in a Pile. Intn. Seminar on the Application of Stress Wave Theory on Piles / Stockholm. 1980.
[4].王奎华、谢康和、曾国熙,有限长桩受迫振动问题解析解及其应用,[J].岩土工程学报,1997,19(6)27-35
[5].王奎华、谢康和、曾国熙,李冰河,弹性支承桩受迫振动问题广义函数解及应用,浙江大学学报(自然科学版),1998,32(5):546-551
[6]. Davis, A. Dunn, C ,,From Theory to Field Experience with the Non-destructive Vibration Testing of Piles,Proceeding of Civil Engineering, 1974
[7].王靖涛,桩基应力波检测理论及工程应用,科学出版社,1999
[8].黎正根、龚育龄,波在大直径桩中传播的三维效应现象,[J],岩土力学与工程学报,1998,17(4):434-439
[9].王奎华,桩基完整性动测定量化及拟合分析,河海大学硕士学位论文,1993
[10].雷林源著,桩基动力学,冶金工业出版社,2000
[11].徐攸在主编,桩的动测新技术(第二版),中国建筑工业出版社,2002
[12].一机部第一设计建研室,《桩基的地基刚度计算方法(条文)代替规程第四稿中条文22、23、24条及修改原因的说明》,1964
[13].王怡、徐攸在,土的动弹性模量与静变形模量关系初探,第四届全国土动力力学学术会议论文集,浙江大学出版社,1994
[14]. G. Gazetas, N.Makris. Dynamic Pile-Soil-Pile Interaction. PartⅠ:Analysis of Axial Vibration [J] Earthquake Eng. Struct.Dyn,1991.20(1):115-132
[15]. .M.Novak,Vertical Vibration of Floating Piles. Journal of Geotechnical Engineering, ASCE,1977, 103(4):271-285
[16]. Smith,E.A.L., Pile Driving Analysis by the Wave Equation, J. of Soil Mechanics and Foundation, ASCE, Vol.86, No.SM4, 1960
[17]. Van Weele,A.F., Middendorp,P. & Reiding,F.J., Detection of Pile Defects with Digital Integrity Testing Equipment, Foundations and Tunnels, London, 1987
[18]. Chow Y K, Phoon K K,Chow W F, et al, Low Strain Integrity Testing of Piles Three-dimensional Effects, Journal of Geotechnical and Geoenvironmental Engineering, 2003,129(11):1057-1062
[19]. Seitz, Low Strain Integrity Testing of Bored Piles. J M Ground Engng V19, N8, Nov 1986, P25-26, 33
[20].罗骐先主编,桩基工程检测手册(第三版),人民交通出版社,2010
[21].王雪峰,基桩低应变完整性检测中的安装谐振影响,[J]岩土力学与工程学报,2002,(04):582-585
[22].邢心魁,反射波法桩基动测技术研究,[D].西安建筑科技大学, 2005 .
[23].刘兴录,动力试桩若干问题的讨论,[J].建筑科学,1988,(5): 37-42
[24].陶明江,张莹,祝龙根,基桩完整性小应变动力检验的定量分析,[J].工程勘察,200,(02):64-65+68
[25].赵振东、杉本三千雄、铃木善雄,基桩完整性小应变动力检验的定量分析,[J],地震工程与工程振动,1995,(04): 104-112
[26].曾国柱、秦莹、张成良,桩基高、低应变法对比检测分析,[J],西部探矿工程,2006,(s1):49-51
[27].安志强、王耀禧、程庆阳、陈少波,断裂桩静载试验结果的特征及评价四川建筑科学研究[J] 2000.12(4)
[28].林天健、熊厚金、王利群,桩基础设计指南,中国建筑工业出版社, 1999
[29]. (美)Anil K. Chopra著,谢礼立、吕大刚等译,结构动力学(第二版),高等教育出版社,2005
[30]. (英)C. F. Beards著,朱世杰、陈玉琼译,结构振动分析,中国铁道出版社,1988
[31].陈强顺编著,分析力学导论,同济大学出版社,1997
[32].刘东甲,纵向振动桩侧壁切应力频率域解及其应用,[J],岩土工程学报,2001,23(5)544-546
[33].张献民,时间域中基桩缺陷低应变动测的定量分析,[J],土木工程学报,2004,37(6)64-69
[34].王建华、智胜英,低应变条件下桩土相互作用的阻尼系数,[J],岩石力学与工程学报,2007,26(9)1800-1808
[35].吴庆曾编著,基桩声测与动测技术,中国电力出版社,2009\
[36].刘屠梅、赵竹占、吴慧明著,桩基检测技术与实例,中国建筑工业出版社,2006
[2].国家标准《建筑地基基础设计规范》GB50007-2002
[3]. Koten H Van, Middendorp P, Brederode P Van:An Analysis of Dissipative Wave Propagation in a Pile. Intn. Seminar on the Application of Stress Wave Theory on Piles / Stockholm. 1980.
[4].王奎华、谢康和、曾国熙,有限长桩受迫振动问题解析解及其应用,[J].岩土工程学报,1997,19(6)27-35
[5].王奎华、谢康和、曾国熙,李冰河,弹性支承桩受迫振动问题广义函数解及应用,浙江大学学报(自然科学版),1998,32(5):546-551
[6]. Davis, A. Dunn, C ,,From Theory to Field Experience with the Non-destructive Vibration Testing of Piles,Proceeding of Civil Engineering, 1974
[7].王靖涛,桩基应力波检测理论及工程应用,科学出版社,1999
[8].黎正根、龚育龄,波在大直径桩中传播的三维效应现象,[J],岩土力学与工程学报,1998,17(4):434-439
[9].王奎华,桩基完整性动测定量化及拟合分析,河海大学硕士学位论文,1993
[10].雷林源著,桩基动力学,冶金工业出版社,2000
[11].徐攸在主编,桩的动测新技术(第二版),中国建筑工业出版社,2002
[12].一机部第一设计建研室,《桩基的地基刚度计算方法(条文)代替规程第四稿中条文22、23、24条及修改原因的说明》,1964
[13].王怡、徐攸在,土的动弹性模量与静变形模量关系初探,第四届全国土动力力学学术会议论文集,浙江大学出版社,1994
[14]. G. Gazetas, N.Makris. Dynamic Pile-Soil-Pile Interaction. PartⅠ:Analysis of Axial Vibration [J] Earthquake Eng. Struct.Dyn,1991.20(1):115-132
[15]. .M.Novak,Vertical Vibration of Floating Piles. Journal of Geotechnical Engineering, ASCE,1977, 103(4):271-285
[16]. Smith,E.A.L., Pile Driving Analysis by the Wave Equation, J. of Soil Mechanics and Foundation, ASCE, Vol.86, No.SM4, 1960
[17]. Van Weele,A.F., Middendorp,P. & Reiding,F.J., Detection of Pile Defects with Digital Integrity Testing Equipment, Foundations and Tunnels, London, 1987
[18]. Chow Y K, Phoon K K,Chow W F, et al, Low Strain Integrity Testing of Piles Three-dimensional Effects, Journal of Geotechnical and Geoenvironmental Engineering, 2003,129(11):1057-1062
[19]. Seitz, Low Strain Integrity Testing of Bored Piles. J M Ground Engng V19, N8, Nov 1986, P25-26, 33
[20].罗骐先主编,桩基工程检测手册(第三版),人民交通出版社,2010
[21].王雪峰,基桩低应变完整性检测中的安装谐振影响,[J]岩土力学与工程学报,2002,(04):582-585
[22].邢心魁,反射波法桩基动测技术研究,[D].西安建筑科技大学, 2005 .
[23].刘兴录,动力试桩若干问题的讨论,[J].建筑科学,1988,(5): 37-42
[24].陶明江,张莹,祝龙根,基桩完整性小应变动力检验的定量分析,[J].工程勘察,200,(02):64-65+68
[25].赵振东、杉本三千雄、铃木善雄,基桩完整性小应变动力检验的定量分析,[J],地震工程与工程振动,1995,(04): 104-112
[26].曾国柱、秦莹、张成良,桩基高、低应变法对比检测分析,[J],西部探矿工程,2006,(s1):49-51
[27].安志强、王耀禧、程庆阳、陈少波,断裂桩静载试验结果的特征及评价四川建筑科学研究[J] 2000.12(4)
[28].林天健、熊厚金、王利群,桩基础设计指南,中国建筑工业出版社, 1999
[29]. (美)Anil K. Chopra著,谢礼立、吕大刚等译,结构动力学(第二版),高等教育出版社,2005
[30]. (英)C. F. Beards著,朱世杰、陈玉琼译,结构振动分析,中国铁道出版社,1988
[31].陈强顺编著,分析力学导论,同济大学出版社,1997
[32].刘东甲,纵向振动桩侧壁切应力频率域解及其应用,[J],岩土工程学报,2001,23(5)544-546
[33].张献民,时间域中基桩缺陷低应变动测的定量分析,[J],土木工程学报,2004,37(6)64-69
[34].王建华、智胜英,低应变条件下桩土相互作用的阻尼系数,[J],岩石力学与工程学报,2007,26(9)1800-1808
[35].吴庆曾编著,基桩声测与动测技术,中国电力出版社,2009\
[36].刘屠梅、赵竹占、吴慧明著,桩基检测技术与实例,中国建筑工业出版社,2006