【作者】 孙容；

【导师】 邹道勤； 金伟良；

【作者基本信息】 浙江大学 ， 结构工程， 2003， 硕士

【摘要】 随着现代社会和经济的发展，桩基础在现代土木工程发展中起了越益巨大的作用。目前我国海洋石油平台、超高层建筑、大跨度桥梁等中所使用的桩基础不仅能承受巨大的竖向荷载，而且能承受较大的水平荷载，以适应现代建筑物高、重、大的要求。 由于传统分析方法已经难于对复杂建筑物的设计问题给出满意的解答，比如高层建筑、海洋平台结构等。只有根据共同作用的原理，对上部结构与桩基相互作用又相互制约的整体进行分析，才能得到比较符合实际的结果。桩-土-上部结构的共同作用是把三者看成一个整体，并要满足相互之间在接触部位的变形协调条件。目前大多数国内外软件对桩基础的分析仅局限于桩基本身，对于桩基和上部结构的相互作用，虽然国内外的学者做了大量的研究，但还存在许多计算模式和应用上的问题。 非线性结构分析系统NSAS是浙江大学结构工程研究所在微型机上开发的具有自主产权的有限元软件，具有较强的可容性。 本文在全面系统地总结国内外最新理论和研究成果的基础上，对桩基础的计算方法进行了详细地比较和分析，提出合理、有效的考虑桩-土相互作用的计算分析方法，编制相应的计算程序，并对桩基在静荷载、动荷载的作用下的承载力性能作了详细的分析。用桩头等效非线性杆件代替桩基础，在NSAS上实现了桩-土-结构共同作用的分析。 在三维受力状态下，由于桩周土的非线性，迭加原理不再适合，而目前许多有限元程序只是简单地把单桩计算得到桩头等效非线性弹簧作为结构的边界条件，这样将导致出现比较大的偏差。本文针对这一问题进行了分析，并提出桩头等效非线性曲线的修正方法，并在NSAS和大型商业软件ANSYS上均可以实现桩-土-结构共同作用的空间效应分析。更多还原

【Abstract】 According to the development of the society and economy,pile foundations have played more and more important effects in the development of modern civil engineering. At present,pile foundations in the offshore petroleum platforms,super high-rise buildings and long span bridges,should not only bear vertical loads but also accept horizontal loads to adapt high,heave,large buildings.It was difficult for the traditional analytical methods to the satisfactory answers to the designs of the complicated buildings,such as high-rise buildings,offshore petroleum platforms. Only through the principle of the common work,the relatively actual result is to be obtained by global considering restricts and interactions of pile-structure each other. The common work of pile-soil-structure is regarded to an entirety,and should meet the coordination condition on contact side each other. At present,the analysis is only confined to pile basic in much domestic and international software. On the interaction of pile basic and top structure,there are many problems of calculation models and applications,through the domestic and international scholars have done some helpful exploration.The systematic of non-linear structure,NSAS,is the finite element software with independent property right in the microcomputer by the Structure Research Institute of Zhejiang University,it has been strong containment.The paper compares and analyses in detail to the methods of the soil-pile interaction,by summarizing on the domestic and international latest theory and research systematically. So the rational and effective method of the soil-pile interaction is put forward and program composition corresponding in this paper. The pile bearing capacity is analyzed respectively with static load,dynamic load. It is achieved the common work of pile-soil-structure on NSAS by using nonlinear bars from single pile calculation as the structure boundaries.The results show that under some 3-D loading conditions,significant error can be induced due to the nonlinear characteristic of pile,simply using a nonlinear spring from single pile calculation as the structure boundaries. Through the study of this problem,that an amendment method is presented for non-linear curve of equivalencepile head. The method can be used to analyze the three dimensional effect on NSAS and commercial software ANSYS.更多还原