基于Wieghardt地基桩基稳定性分析  

Stability analysis of pile on a Wieghardt-type elastic foundation

作　　者：张永兴[1] 陈林[1] 吴曙光[1] 

机构地区：[1]重庆大学土木工程学院,重庆400045

出　　处：《岩土工程学报》2010年第S2期9-12,共4页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50878218);国家杰出青年科学基金项目(50625824)

摘　　要：基于Wieghardt地基模型,考虑剪力对桩受力的影响,采用梁的弯曲微分方程,利用梁单元间的位移、转角、弯矩和剪力协调条件,桩的整体平衡条件,建立了不计桩侧摩阻力时两端铰支完全埋入土桩的微分方程,并给出了基桩屈曲临界荷载。利用本文解答分析了地基基床系数对基桩屈曲荷载的影响。结果表明,考虑桩侧有明显土体约束计算的桩屈曲荷载明显大于没有考虑侧向约束桩的屈曲荷载,说明桩侧约束对桩的稳定性具有重要影响;并且基桩屈曲临界荷载随地基基床系数a,b增大而减小;对于细长桩,纯弯曲状态时的屈曲荷载小于考虑剪切变形时的屈曲荷载,实际计算中应采用纯弯曲变形时的屈曲荷载。Based on the differential equation for curvature of pile,a method for piles on Wieghardt foundation is deduced with compatibility conditions of displacement,angular rotation,moment and shear of adjacent pile elements.Lastly,the effect of sub-grade coefficient on the buckling load and the behavior of the pile after flexural buckling are analyzed,which shows that the buckling load which is considering the sidewise restraint is bigger than the traditional Euler's buckling load which is not taking the sidewise restraint into account.The results show that the pile side restrains have significant effect on the pile stability;And the buckling load decreases with the increase of the sub-grade coefficient a,b.As for a slender pile,the buckling load when only considering purely flexible pile is less than that when considering shear deformation,in actual calculation one should use a purely flexible pile model.

关 键 词：Wieghardt地基 屈曲荷载 地基基床系数 

分 类 号：TU473.1[建筑科学—结构工程]