【作者】 陈荣保；

【导师】 陆瑞明；

【作者基本信息】 广东工业大学 ， 岩土工程， 2006， 硕士

【摘要】 预应力混凝土管桩是预应力技术与离心制管技术相结合的产物,由于其具有诸多的优点而在软土地基城市建设中获得日益广泛的应用。然而,打桩过程中由于受到施工因素的影响,常常导致预应力管桩偏斜。目前对于偏斜预应力管桩单桩和偏斜预应力管桩群桩承载性能的研究还不多,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。 本文首先对偏斜预应力管桩单桩的工作性状进行研究。基于数值方法的基础上,对Bowles方法分析偏斜预应力管桩单桩进行改进,桩与土之间工作机理采用荷载传递函数法,避免了现场测量的限制。用FORTRAN程序进行编程,用该程序分析了偏斜预应力管桩单桩承载力的影响因素。结果表明偏斜桩的承载力不仅与其偏斜值有关,且与土层的性质关系密切,从而论证了规程规定管桩的允许偏差为1%的局限性。 其次,利用有限元分析软件ANSYS建立了偏斜预应力管桩单桩力学模型,通过对多层土体例题计算结果分析,得出该模型计算结果与FORTRAN程序计算结果相吻合,说明用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,可以采用ANSYS来分析偏斜预应力管桩群桩的工作性状。接着分析偏斜预应力管桩群工作性状的影响因素,得出一些有意义的结论。 最后,通过工程实例,分析偏斜预应力管桩单桩与群桩工作性状的区别,结果表明:偏斜预应力管桩单桩与群桩之间的工作机理明显不同,从而得到了一些对偏斜预应力管桩加固处理具有指导意义的措施。本文的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有一定的帮助。更多还原

【Abstract】 With the technique of pre-stressing force and centrifugal technique, a new type of pre-stressed concrete pipe-pile has been presented. It is extensively used nowadays in the cities in which soft clay foundation is common because of its various advantages. However, it is often sloping in soft clay during driving piles. The vertical bearing capacity of the sloping pre-stressed concrete pipe-pile is different with the vertical pre-stressed concrete pipe-pile. There is less research about the bearing capacity behavior of the sloping pre-stressed single pile and the sloping pre-stressed pipe-pile group. It is puzzling scientific researchers and engineers about how to evaluate bearing capacity behavior of the sloping pre-stressed pipe-pile correctly.Firstly, in this paper, the bearing capacity behavior of the sloping pre-stressed single pipe-pile is studied. Based on numerical analysis, Bowles method is improved by employing the load transfer function of pile shaft soil. The program is designed in the software of FORTRAN. The influencing factors on bearing capacity behavior of the sloping pre-stressed single pipe-pile has been studied by employing the program. The result indicates that the bearing capacity of the sloping single pile not only has relation with the sloping situation, but also has relation with the soil nature. A conclusion can be made that 1% of slope given by specification about pipe-pile is not perfect.Secondly, the software ANSYS was used to build the mechanical model for the sloping pre-stressed single pipe-pile. The computational results of mechanical model in various soil agree well with the computational results of program. It is reasonable for us to employ the mechanical model to research the behavior of the sloping pre-stressed pipe-pile. Moreover, the influencing factors on bearing capacity behavior of the sloping pre-stressed pipe-pile group has been studied by employing the program and some guidable conclusions are obtained.Finally, the author has analyzed the difference of bearing capacity behavior between the sloping pre-stressed single pipe-pile and the sloping pre-stressed pipe-pile group. The result indicates that it is rather different about the bearing capacity behaviorbetween the sloping pre-stressed single pipe-pile and the sloping pre-stressed pipe-pile group. Therefore, some guidable measures than can guide the engineers to reinforce and process the sloping pre-stressed pipe-pile are obtained. The results will be helpful for engineering application and more research about the behavior of the sloping pre-stressed pipe-pile.更多还原