砂土地基斜桩水平承载特性p-y曲线法
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摘要
基于Reese建议的砂土p-y曲线,提出了适用于斜桩水平承载特性分析的修正p-y曲线及相应的有限元分析方法。根据桩前土体受力特点,假设桩前浅层土体达到极限破坏状态时桩侧被动破坏区为一个三维楔形体,采用极限平衡分析方法导出了斜桩桩侧极限土抗力表达式,对比研究了斜桩倾角、桩-土界面摩擦系数等因素对极限土抗力的影响规律,并给出了斜桩初始地基反力模量确定方法。在此基础上,修正Reese提出的直桩p-y曲线,提出了砂土地基中斜桩p-y曲线确定方法。利用虚功原理,导出了斜桩水平承载特性分析的有限单元列式,编制相应的分析程序,通过算例验证了方法的合理性和有效性。最后,采用修正的p-y曲线法对一离心机模型试验进行了模拟分析,结果表明,计算与试验结果吻合得很好。
Based on the p-y curve method for plumb pile in sand proposed by Reese,a new p-y curve method and its corresponding finite element method for analyzing horizontal bearing characteristics of single batter pile are presented.Firstly,according to the mechanical behavior of the shallow soil near a batter pile,a three-dimensional wedge model is put forward to describe the passive region which is in the limit state.By using limit equilibrium analysis method,the expression of ultimate soil resistance of batter pile is derived.Then,the influences of pile angle and the friction between pile and soil are numerically studied;and the method for determining the initial modulus of p-y curve of batter pile is given.By modifying the p-y curve for plumb pile in sands proposed by Reese,the p-y curve for batter pile in sand is obtained.Using the virtual work principle,the finite element formulations for horizontal bearing analysis of single batter pile are deduced;and the iteration algorithm is put forwards.The corresponding program is coded by authors;and numerical examples are taken to illustrate the effectiveness of the method.Finally,a printed centrifuge model test of batter pile is analyzed by the presented method.The numerical results show fine agreement with those of model test.
Based on the p-y curve method for plumb pile in sand proposed by Reese,a new p-y curve method and its corresponding finite element method for analyzing horizontal bearing characteristics of single batter pile are presented.Firstly,according to the mechanical behavior of the shallow soil near a batter pile,a three-dimensional wedge model is put forward to describe the passive region which is in the limit state.By using limit equilibrium analysis method,the expression of ultimate soil resistance of batter pile is derived.Then,the influences of pile angle and the friction between pile and soil are numerically studied;and the method for determining the initial modulus of p-y curve of batter pile is given.By modifying the p-y curve for plumb pile in sands proposed by Reese,the p-y curve for batter pile in sand is obtained.Using the virtual work principle,the finite element formulations for horizontal bearing analysis of single batter pile are deduced;and the iteration algorithm is put forwards.The corresponding program is coded by authors;and numerical examples are taken to illustrate the effectiveness of the method.Finally,a printed centrifuge model test of batter pile is analyzed by the presented method.The numerical results show fine agreement with those of model test.
引文
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[6]ZHANG L M,MCVAY M C,HAN S J,et al.Effects ofdead loads on the lateral response of battered pilegroups[J].Canadian Geotechnical Journal,2002,39(3):561-575.
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[8]云天铨.线载荷积分方程法分析桩顶受任意荷载的弹性斜桩[J].应用数学和力学,1999,20(4):351-357.YUN Tian-quan.Analysis of sloping elastic pile underarbitrary loads by line-loaded integral equation method[J].Applied Mathematics and Mechanics,1999,20(4):351-357.
[9]REESE L C,COX W R,KOOP F D.Analysis of laterallyloaded piles in sand[C]//Proceedings of the 6th Annualoffshore Technology Conference.Houston:[s.n.],1974:473-483.
[10]RAJASHREE S S,SITHARAM T G.Nonlinearfinite-element modeling of batter piles under lateralloads[J].Journal of Geotechnical and Geo-environmental Engineering,2001,127(7):604-612.
[11]吕凡任.倾斜荷载作用下斜桩基础工作性状研究[D].杭州:浙江大学,2004.
[12]刘杰伟,王兴斌,潘健,等.桩群中设置斜桩对其工作性质影响的研究[J].昆明理工大学学报(理工版),2008,33(1):56-59.LIU Jie-wei,WANG Xing-bin,PAN Jian,et al.Study oneffects of construction of raked piles in a pile group[J].Journal of Kunming University of Science andTechnology(Science and Technology),2008,33(1):56-59.
[13]杨征宇.输电塔基础斜桩非线性p-y曲线[J].河海大学学报(自然科学版),2010,38(1):104-108.YANG Zheng-yu.Nonlinear p-y curve for batter pilesinfoundation of transmission towers[J].Journal of HohaiUniversity(Natural Sciences),2010,38(1):104-108.
[14]SHERIF M A,ISHIBASHI I,LEE C D.Earth pressur-esagainst rigid retaining walls[J].Journal of theGeotechnical Engineering Division,1982,108(5):679-69.
[15]JARDINE R J,CHOW F C.New design methods foroffshore piles[M].London:MTD Publication,1996.
[16]DAS B M.Principles of foundation engineering[M].Calif:Pacific Grove PWS Publishing,1999.
[2]MEYERHOF G G,YALCINAS.Behaviour of flexiblebatter piles under inclined loads in layered soil[J].Canadian Geotechnical Journal,1993,30(2):247-256.
[3]SASTRYVVRN,MEYERHOF G G.Behaviour offlexible piles in layered clays under eccentric and inclinedloads[J].Canadian Geotechnical Journal,1995,32(4):387-396.
[4]MEYERHOF G G.Behaviour of pile foundations underspecial loading conditions:1994 R.M.Hardy keynoteaddress[J].Canadian Geotechnical Journal,1995,32(2):204-222.
[5]ZHANG L M,MCVAY M C,LAI P W.Centrifugemodeling of laterally loaded single battered piles insands[J].Canadian Geotechnical Journal,1999,36(6):1074-1084.
[6]ZHANG L M,MCVAY M C,HAN S J,et al.Effects ofdead loads on the lateral response of battered pilegroups[J].Canadian Geotechnical Journal,2002,39(3):561-575.
[7]云天铨,云飞,张桂标.刚性斜桩顶部受任意力的位移线载荷积分方程法的分析[J].应用力学学报,1992,9(4):114-123.YUN Tian-qun,YUN Fei,ZHANG Gui-biao.Analysis ofthe displacement of rigid battered pile under arbitraryloads at the top by line-loaded integral equationmethod[J].Applied Mathematics and Mechanics,1992,9(4):114-123.
[8]云天铨.线载荷积分方程法分析桩顶受任意荷载的弹性斜桩[J].应用数学和力学,1999,20(4):351-357.YUN Tian-quan.Analysis of sloping elastic pile underarbitrary loads by line-loaded integral equation method[J].Applied Mathematics and Mechanics,1999,20(4):351-357.
[9]REESE L C,COX W R,KOOP F D.Analysis of laterallyloaded piles in sand[C]//Proceedings of the 6th Annualoffshore Technology Conference.Houston:[s.n.],1974:473-483.
[10]RAJASHREE S S,SITHARAM T G.Nonlinearfinite-element modeling of batter piles under lateralloads[J].Journal of Geotechnical and Geo-environmental Engineering,2001,127(7):604-612.
[11]吕凡任.倾斜荷载作用下斜桩基础工作性状研究[D].杭州:浙江大学,2004.
[12]刘杰伟,王兴斌,潘健,等.桩群中设置斜桩对其工作性质影响的研究[J].昆明理工大学学报(理工版),2008,33(1):56-59.LIU Jie-wei,WANG Xing-bin,PAN Jian,et al.Study oneffects of construction of raked piles in a pile group[J].Journal of Kunming University of Science andTechnology(Science and Technology),2008,33(1):56-59.
[13]杨征宇.输电塔基础斜桩非线性p-y曲线[J].河海大学学报(自然科学版),2010,38(1):104-108.YANG Zheng-yu.Nonlinear p-y curve for batter pilesinfoundation of transmission towers[J].Journal of HohaiUniversity(Natural Sciences),2010,38(1):104-108.
[14]SHERIF M A,ISHIBASHI I,LEE C D.Earth pressur-esagainst rigid retaining walls[J].Journal of theGeotechnical Engineering Division,1982,108(5):679-69.
[15]JARDINE R J,CHOW F C.New design methods foroffshore piles[M].London:MTD Publication,1996.
[16]DAS B M.Principles of foundation engineering[M].Calif:Pacific Grove PWS Publishing,1999.