多向水平荷载作用下的群桩效应研究
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摘要
桩基础通常是以群桩形式存在的,本文采用室内模型试验研究的手段对砂土中群桩进行单向加载和多向加载,最后将数值模拟与试验结果进行对比。
首先,对单桩进行了单向加载及多向加载的研究发现,各桩的水平力和位移呈非线性关系,在多向加载情况下,单桩的最大水平力明显小于单向加载条件下的最大水平力。
其次,对3D(即3倍桩径)群桩进行了沿不同角度的单向加载试验,结果表明:群桩中各桩的水平力和位移均呈非线性关系,各桩的最大水平力均小于单桩单向加载时的最大水平力,随着加载角度的增加,前排桩的最大水平力趋近于单桩单向加载时的最大水平力。
然后,改变桩间距进行沿不同角度的单向加载试验,结果表明:在不同桩间距下,各桩的最大水平力均小于单桩单向加载时的最大水平力,随着桩间距的增加,前排桩的最大水平力趋近于单桩单向加载时的最大水平力,群桩的总合力随着桩间距的增加而增加。
接下来进行了3D群桩的多向加载试验,试验结果表明:多向加载条件下,群桩中各桩最大水平力均小于单桩单向加载时最大水平力,并且8字加载时最大水平力出现在最大位移之前。
最后,在试验结果的基础上,对各桩水平力变化进行了数值模拟,最后结果显示群桩中各桩的p-y曲线模拟图,采用动态折减系数时要明显更接近于试验结果。
Usually pile foundation is in the form of pile groups. Model tests of pile groups in sandy soil under unidirectional and directional loadings were performed. Finally the numerical simulation was compared with the experimental results.
First, the research of single pile under unidirectional and multidirectional horizontal loadings showed that the force and displacement of each pile was nonlinear, in the case of directional loadings, the maximum horizontal force of each pile was obviously less than the maximum horizontal force of single pile under unidirectional loadings.
Then, the results of the pile groups of 3D (D is the pile diameter) along different angle under unidirectional horizontal loadings showed that the force and displacement of each pile in the pile groups were nonlinear, the maximum horizontal force of each pile in the pile groups was less than the maximum horizontal force under unidirectional loadings of single pile test. Along with the increase of load angle, the maximum horizontal force of the front row pile was close to the maximum horizontal force of single pile under unidirectional loadings.
After that the results of the pile groups with different pile spacing along different angle under unidirectional horizontal loadings showed that under different pile spacing, the maximum horizontal force of each pile in the pile groups was less than the maximum horizontal force under unidirectional loadings of single pile test. Along with the increase of pile spacing, the maximum horizontal force of the front row pile was close to the maximum horizontal force of single pile under unidirectional loadings. The total horizontal force of the pile groups was increased as the pile spacing increased.
And then the results of the pile groups of 3D under multidirectional horizontal loadings showed that the maximum horizontal force was disappeared before the maximum displacement under the figure-8 loading.
Finally, based on the results of tests, the change of each pile’s horizontal force was simulated. The results showed that the p-y curve of numerical simulation was closer to the experimental results by using the dynamic p-multiplier.
首先,对单桩进行了单向加载及多向加载的研究发现,各桩的水平力和位移呈非线性关系,在多向加载情况下,单桩的最大水平力明显小于单向加载条件下的最大水平力。
其次,对3D(即3倍桩径)群桩进行了沿不同角度的单向加载试验,结果表明:群桩中各桩的水平力和位移均呈非线性关系,各桩的最大水平力均小于单桩单向加载时的最大水平力,随着加载角度的增加,前排桩的最大水平力趋近于单桩单向加载时的最大水平力。
然后,改变桩间距进行沿不同角度的单向加载试验,结果表明:在不同桩间距下,各桩的最大水平力均小于单桩单向加载时的最大水平力,随着桩间距的增加,前排桩的最大水平力趋近于单桩单向加载时的最大水平力,群桩的总合力随着桩间距的增加而增加。
接下来进行了3D群桩的多向加载试验,试验结果表明:多向加载条件下,群桩中各桩最大水平力均小于单桩单向加载时最大水平力,并且8字加载时最大水平力出现在最大位移之前。
最后,在试验结果的基础上,对各桩水平力变化进行了数值模拟,最后结果显示群桩中各桩的p-y曲线模拟图,采用动态折减系数时要明显更接近于试验结果。
Usually pile foundation is in the form of pile groups. Model tests of pile groups in sandy soil under unidirectional and directional loadings were performed. Finally the numerical simulation was compared with the experimental results.
First, the research of single pile under unidirectional and multidirectional horizontal loadings showed that the force and displacement of each pile was nonlinear, in the case of directional loadings, the maximum horizontal force of each pile was obviously less than the maximum horizontal force of single pile under unidirectional loadings.
Then, the results of the pile groups of 3D (D is the pile diameter) along different angle under unidirectional horizontal loadings showed that the force and displacement of each pile in the pile groups were nonlinear, the maximum horizontal force of each pile in the pile groups was less than the maximum horizontal force under unidirectional loadings of single pile test. Along with the increase of load angle, the maximum horizontal force of the front row pile was close to the maximum horizontal force of single pile under unidirectional loadings.
After that the results of the pile groups with different pile spacing along different angle under unidirectional horizontal loadings showed that under different pile spacing, the maximum horizontal force of each pile in the pile groups was less than the maximum horizontal force under unidirectional loadings of single pile test. Along with the increase of pile spacing, the maximum horizontal force of the front row pile was close to the maximum horizontal force of single pile under unidirectional loadings. The total horizontal force of the pile groups was increased as the pile spacing increased.
And then the results of the pile groups of 3D under multidirectional horizontal loadings showed that the maximum horizontal force was disappeared before the maximum displacement under the figure-8 loading.
Finally, based on the results of tests, the change of each pile’s horizontal force was simulated. The results showed that the p-y curve of numerical simulation was closer to the experimental results by using the dynamic p-multiplier.
引文
[1]茜平一,周洪波.水平荷载群桩三维有限元分析研究.岩土工程技术.1999, 04:4-48.
[2]谢耀峰.横向承载群桩性状及承载力研究.岩土工程学报.1996,06:39-45.
[3]王振,彭斌.地基处理中桩基水平承载特性研究探讨.山西建筑,2008, 25:142-143.
[4]苏栋.水平(椭)圆形加载路径下的单桩模型试验研究.岩土工程学报.2011,33(5).
[5]王成,邓安福.水平荷载桩桩土共同作用全过程分析.岩土工程学报. 2001, 23(4): 476-480
[6] Gazioglu S.M., O’Neill M.W. Evaluation of p-y Relationships in Cohesive Soils. Proceedings of the ASCE Symposium on Analysis and Design of Pile Foundations, ASCE National Convention, San Francisco, California, 1984: 192-213
[7] Reese, L. C., Cox, W. R. and Koop, F. B. Analysis of Laterally Loaded Piles in Sand. Proc., Offshore Technology Conf., Houston, Paper No. OTC 1974,2080
[8] Matlock H S, and Reese, LC. Foundation Analysis of Offshore Pile Supported Structures. Proceedings of the 5th International Conference on Soil Mechanics and Foundation Engineering. Paris, France.1961
[9] Matlock H S, and Reese, L. C. Generalized Solutions for Laterally Loaded Piles. Soil Mech. Found. Eng. 1960,86(5): 63–91
[10] Dunnavant T.W., and O’Neill M.W. Experimental p-y Model for Submerged Stiff Clay. Journal of Geotechnical Engineering. 1989, 115(1): 95-114
[11] Murchison J.M., O’Neill M.W. Evaluation of p-y Relationships in Cohesionless Soils. Proceedings of the ASCE Symposium on Analysis and Design of PileFoundations, ASCE National Convention, San Francisco, California, 1984: 174-191
[12] Matlock H S. Correlations for Design of Laterally Loaded Piles in Soft Clay. Proc., Offshore Technology Conf., Houston, Paper No. OTC 1970,1204
[13]陈菊香,刘克萍,俞亚南,冯世挺.基于P-Y曲线的水平承载群桩有限元分析.江南大学学报. 2005(4): 163-167
[14] JGJ-94建筑桩基技术规范[S].北京:中国建筑工业出版社,2008.
[15] JTJ024-85公路桥涵地基与基础设计规范[S].人民交通出版社,1985.
[16] JTJ254-98港口工程桩基规范[S].人民交通出版社,2001.
[17]王梅,楼志刚,李建乡,赵京.水平荷载作用下单桩非线性m法试验研究[J].岩土力学,2002,23:23-26.
[18]叶万灵,时蓓玲.桩的水平承载力实用非线性计算方法-NL法[J].岩土力学,2000,21:97-101.
[19]贾庆山.线弹性地基反力法计算桩基水平力[J].高桥石化,1992,3:18-23
[20]苏静波,邵国建,刘宁.基于p-y曲线法的水平受荷桩非线性有限元分析[J].岩土力学,2006,27:1781-1785.
[21]赵明华,汪优,黄靓.水平受荷桩的非线性无网格法分析[J].岩土工程学报,2005,27:907-912.
[22]乔友刚,吴先敏.水平受荷桩非线性有限元分析[J].水运工程.2009.04:38-42.
[23] Allotey Nil and EI Naggar M. Hesham. A numerical study into lateral cyclic nonlinear soil-pile response[J]. Canadian Geotechnical Journal. 2008,45:1268-1281.
[24] Fan Chia-Cheng and Long H. James. Assessment of existing methods for predicting soil response of laterally loaded piles in sand[J]. Computers and Geotechnics.2005,32:274-289.
[25] Chang Der-Wen, Bor-Lin Shiun and Cheng Shih-Hao. Lateral load distributions on grouped piles from dynamic pile-to-pile interaction factors[J].International Journal for Numerical and Analytical Methods in Geomechanics.2009,33:173-191.
[26] Guo Wei Dong. Nonlinear response of laterally loaded piles and pile groups[J]. International Journal for Numerical and Analytical Methods in Geomechanics. 2009,33:879-914.
[27] Gerolymos Nikos, Escoffi Sandra, Gazetas George and Garnier Jacques. Numerical modeling of centrifuge cyclic lateral pile load experiments[J]. Earthquake Engineering and Engineering Vibration.2009,8:61-76.
[28] Ashour M, Norris G, and Pilling P. Lateral Loading of a Pile in Layered Soil Using the Strain Wedge Model. J. Geotech. Geoenviron. Eng. 1998,124(4): 303–315
[29] Ashour M, Pilling P, and Norris G. Lateral Behavior of Pile Groups in Layered Soils. Geotech. Geoenviron. Eng. 2004,130(6): 580–592
[30] Brown DA, Morrison C and Reese LC. Lateral load behavior of a pile group in sand. J. Geotech. Engrg. ASCE. 1988,114(11):1261-1276.
[31] Michael McVay, Limin Zhang, Thomas Molnit, Peter Lai. Centrifuge testing of large laterally loaded pile groups in sands.J. Geotech And Geoenvir. Engrg,ASCE, 1998,124:1016-1026.
[32] Ilyas T, Leung CF, Chow YK, and Budi SS.(2004) Centrifuge Model Study of Laterally Loaded Pile Groups in Clay. Journal of Geotechnical and Geoenvironmental Engineering, 2004,Vol. 130, No. 3:274-283.
[33] S.S.Chandrasekaran, A.Boominathan, G.R.Dodagoudar. Journal of Geotechnical and Geoenvironmental Engineering, 2010,Vol. 130, No. 4:574-582.
[34]何光春,粘土中横向受荷群桩性状的试验研究.重庆交通学院学报. 1989.8:79-88.
[35]杨克己.水平力作用下群桩性状的研究[J].岩土工程学报.1990,03:42-52.
[36]谢耀峰.水平荷载下群桩p-y曲线的试验研究.土工基础.1996,10:27-34.
[37]周洪波,杨敏,茜平一.水平荷载作用下群桩相互作用的弹塑性数值分析.水文地质工程地质.2003,3:29-35.
[38]周常春,邓安福,张明义,干腾君,潘晋.水平荷载下群桩前后土抗力分布的数值分析.地下空间.2003,23:17-21.
[39]卢成原,孟繁丽.承受水平荷载群桩研究进展,浙江工业大学学报.2001(12):405-409.
[40]冯世挺.横向承载群桩性状及承载力研究.浙江大学硕士生论文.2003:21-35
[41]韩洁.横向静载群桩效应研究.河海大学硕士生论文.2001:18-45
[42]韩理安.桩基水平承载力的群桩效率[J].岩土工程学报.1984,6:66-74.
[43]袁胜强.水平多向荷载下砂土中桩基础的弹塑性数值分析.哈尔滨工业大学硕士学位论文.2010:28-72
[44]苏栋.弹塑性p-y模型及非线性地基梁的增量有限元法.岩土工程学报(审稿中)
[45] Poulos, H.G., Davies, E.H. Pile Foundation Analysis and Design. John Wiley and Sons, New York, NY. 1980
[2]谢耀峰.横向承载群桩性状及承载力研究.岩土工程学报.1996,06:39-45.
[3]王振,彭斌.地基处理中桩基水平承载特性研究探讨.山西建筑,2008, 25:142-143.
[4]苏栋.水平(椭)圆形加载路径下的单桩模型试验研究.岩土工程学报.2011,33(5).
[5]王成,邓安福.水平荷载桩桩土共同作用全过程分析.岩土工程学报. 2001, 23(4): 476-480
[6] Gazioglu S.M., O’Neill M.W. Evaluation of p-y Relationships in Cohesive Soils. Proceedings of the ASCE Symposium on Analysis and Design of Pile Foundations, ASCE National Convention, San Francisco, California, 1984: 192-213
[7] Reese, L. C., Cox, W. R. and Koop, F. B. Analysis of Laterally Loaded Piles in Sand. Proc., Offshore Technology Conf., Houston, Paper No. OTC 1974,2080
[8] Matlock H S, and Reese, LC. Foundation Analysis of Offshore Pile Supported Structures. Proceedings of the 5th International Conference on Soil Mechanics and Foundation Engineering. Paris, France.1961
[9] Matlock H S, and Reese, L. C. Generalized Solutions for Laterally Loaded Piles. Soil Mech. Found. Eng. 1960,86(5): 63–91
[10] Dunnavant T.W., and O’Neill M.W. Experimental p-y Model for Submerged Stiff Clay. Journal of Geotechnical Engineering. 1989, 115(1): 95-114
[11] Murchison J.M., O’Neill M.W. Evaluation of p-y Relationships in Cohesionless Soils. Proceedings of the ASCE Symposium on Analysis and Design of PileFoundations, ASCE National Convention, San Francisco, California, 1984: 174-191
[12] Matlock H S. Correlations for Design of Laterally Loaded Piles in Soft Clay. Proc., Offshore Technology Conf., Houston, Paper No. OTC 1970,1204
[13]陈菊香,刘克萍,俞亚南,冯世挺.基于P-Y曲线的水平承载群桩有限元分析.江南大学学报. 2005(4): 163-167
[14] JGJ-94建筑桩基技术规范[S].北京:中国建筑工业出版社,2008.
[15] JTJ024-85公路桥涵地基与基础设计规范[S].人民交通出版社,1985.
[16] JTJ254-98港口工程桩基规范[S].人民交通出版社,2001.
[17]王梅,楼志刚,李建乡,赵京.水平荷载作用下单桩非线性m法试验研究[J].岩土力学,2002,23:23-26.
[18]叶万灵,时蓓玲.桩的水平承载力实用非线性计算方法-NL法[J].岩土力学,2000,21:97-101.
[19]贾庆山.线弹性地基反力法计算桩基水平力[J].高桥石化,1992,3:18-23
[20]苏静波,邵国建,刘宁.基于p-y曲线法的水平受荷桩非线性有限元分析[J].岩土力学,2006,27:1781-1785.
[21]赵明华,汪优,黄靓.水平受荷桩的非线性无网格法分析[J].岩土工程学报,2005,27:907-912.
[22]乔友刚,吴先敏.水平受荷桩非线性有限元分析[J].水运工程.2009.04:38-42.
[23] Allotey Nil and EI Naggar M. Hesham. A numerical study into lateral cyclic nonlinear soil-pile response[J]. Canadian Geotechnical Journal. 2008,45:1268-1281.
[24] Fan Chia-Cheng and Long H. James. Assessment of existing methods for predicting soil response of laterally loaded piles in sand[J]. Computers and Geotechnics.2005,32:274-289.
[25] Chang Der-Wen, Bor-Lin Shiun and Cheng Shih-Hao. Lateral load distributions on grouped piles from dynamic pile-to-pile interaction factors[J].International Journal for Numerical and Analytical Methods in Geomechanics.2009,33:173-191.
[26] Guo Wei Dong. Nonlinear response of laterally loaded piles and pile groups[J]. International Journal for Numerical and Analytical Methods in Geomechanics. 2009,33:879-914.
[27] Gerolymos Nikos, Escoffi Sandra, Gazetas George and Garnier Jacques. Numerical modeling of centrifuge cyclic lateral pile load experiments[J]. Earthquake Engineering and Engineering Vibration.2009,8:61-76.
[28] Ashour M, Norris G, and Pilling P. Lateral Loading of a Pile in Layered Soil Using the Strain Wedge Model. J. Geotech. Geoenviron. Eng. 1998,124(4): 303–315
[29] Ashour M, Pilling P, and Norris G. Lateral Behavior of Pile Groups in Layered Soils. Geotech. Geoenviron. Eng. 2004,130(6): 580–592
[30] Brown DA, Morrison C and Reese LC. Lateral load behavior of a pile group in sand. J. Geotech. Engrg. ASCE. 1988,114(11):1261-1276.
[31] Michael McVay, Limin Zhang, Thomas Molnit, Peter Lai. Centrifuge testing of large laterally loaded pile groups in sands.J. Geotech And Geoenvir. Engrg,ASCE, 1998,124:1016-1026.
[32] Ilyas T, Leung CF, Chow YK, and Budi SS.(2004) Centrifuge Model Study of Laterally Loaded Pile Groups in Clay. Journal of Geotechnical and Geoenvironmental Engineering, 2004,Vol. 130, No. 3:274-283.
[33] S.S.Chandrasekaran, A.Boominathan, G.R.Dodagoudar. Journal of Geotechnical and Geoenvironmental Engineering, 2010,Vol. 130, No. 4:574-582.
[34]何光春,粘土中横向受荷群桩性状的试验研究.重庆交通学院学报. 1989.8:79-88.
[35]杨克己.水平力作用下群桩性状的研究[J].岩土工程学报.1990,03:42-52.
[36]谢耀峰.水平荷载下群桩p-y曲线的试验研究.土工基础.1996,10:27-34.
[37]周洪波,杨敏,茜平一.水平荷载作用下群桩相互作用的弹塑性数值分析.水文地质工程地质.2003,3:29-35.
[38]周常春,邓安福,张明义,干腾君,潘晋.水平荷载下群桩前后土抗力分布的数值分析.地下空间.2003,23:17-21.
[39]卢成原,孟繁丽.承受水平荷载群桩研究进展,浙江工业大学学报.2001(12):405-409.
[40]冯世挺.横向承载群桩性状及承载力研究.浙江大学硕士生论文.2003:21-35
[41]韩洁.横向静载群桩效应研究.河海大学硕士生论文.2001:18-45
[42]韩理安.桩基水平承载力的群桩效率[J].岩土工程学报.1984,6:66-74.
[43]袁胜强.水平多向荷载下砂土中桩基础的弹塑性数值分析.哈尔滨工业大学硕士学位论文.2010:28-72
[44]苏栋.弹塑性p-y模型及非线性地基梁的增量有限元法.岩土工程学报(审稿中)
[45] Poulos, H.G., Davies, E.H. Pile Foundation Analysis and Design. John Wiley and Sons, New York, NY. 1980