偏斜预应力管桩的承载力分析与处理

目前对于偏斜预应力管桩承载性能的研究还不多见,如何正确评价偏斜预应力管桩的承载能力仍一直困扰着科研和工程技术人员。采用数值计算,对分析偏斜预应力管桩单桩的Bowles方法进行改进。桩与土之间作用机制采用荷载传递法,可避免现场测量的限制。利用有限元分析软件ANSYS建立偏斜预应力管桩单桩力学模型,通过对多层土体算题计算,得出该模型计算结果与FORTRAN程序计算结果相吻合,说明采用ANSYS软件建立模型分析偏斜预应力管桩工作性状具有一定的合理性,可采用该模型分析偏斜预应力管桩的工作性状。通过工程实例,分析补桩与加地基梁对偏斜预应力管桩工作性状的影响及偏斜预应力管桩单桩与群桩受力机制的区别。研究结果表明:补桩与加地基梁可明显提高偏斜预应力管桩的竖向承载力,偏斜预应力管桩单桩与群桩之间的工作机制明显不同,从而得到一些对偏斜预应力管桩加固处理具有指导意义的措施。所得结论对偏斜预应力管桩工作性状的进一步研究和工程应用具有一定的参考价值。

ANALYSIS AND TREATMENT OF BEARING CAPACITY BEHAVIOR OF SLOPING PRESTRESSED PIPE-PILE

The bearing capacity behavior of the sloping prestressed pipe-pile is seldom seen,and it is a hot topic for scientific researchers and engineers about how to evaluate bearing capacity behavior of the sloping prestressed pipe-pile correctly.Based on numerical calculation,Bowles method is improved by employing the load transfer function of pile shaft soil.The ANSYS is used to build the mechanical model for the sloping prestressed single pipe-pile.The computational results of mechanical model in various soils agree well with the computational results with FORTRAN.It is reasonable to employ the mechanical model to research the behavior of the sloping prestressed pipe-pile.Finally,the influences of subjoining pile and adding footing beam to the bearing capacity behavior of the sloping prestressed pipe-pile are analyzed,and the difference of bearing capacity behavior between the sloping prestressed single pipe-pile and the sloping prestressed pipe-pile group are studied by engineering example.The results indicate that subjoining pile and adding footing beam can obviously increase the vertical bearing capacity of the sloping prestressed pipe-pile,and it is rather different for the bearing capacity behaviors between the sloping prestressed single pipe-pile and the sloping prestressed pipe-pile group.Some references that can guide the engineers to reinforce and process the sloping prestressed pipe-pile are obtained;and it is important to ensure the construction safe.The results will be helpful for engineering application and further research about the bearing capacity behavior of the sloping prestressed pipe-pile.