【作者】 张伟；

【导师】 邵旭东；

【作者基本信息】 湖南大学 ， 桥梁与隧道工程， 2004， 硕士

【摘要】 在实际的超薄梁桥中，经常出现预应力张拉、徐变过程中反拱过大、反向开裂等问题。为了解决上述问题，本文提出了二次预应力组合结构这一新型预应力混凝土超薄梁结构，并从理论分析和试验研究两个方面出发，对其在施工阶段、徐变阶段和使用阶段的性能和特点等多方面进行了探索研究。 从超薄梁的发展开始，由实际工程中经常遇到的问题出发，结合几种已有的预应力结构的特点引出了新型二次预应力组合结构的概念。并通过试验梁的制作，介绍了二次预应力组合结构的基本原理和施工工艺等。 从二次预应力组合结构的施工工艺出发，研究了其在施工阶段的结构分析方法，并通过试验与常规预应力结构进行了比较，介绍了该结构的一些特点和优点，并说明了该结构具有良好的推广前景和应用价值。本文还研究了影响二次预应力组合结构的这些特点的一些影响因素。 基于线性徐变理论和变形协调原理，提出了二次预应力组合结构的应力重分布的计算公式，并研究了影响其应力重分布的主要因素。通过与常规预应力结构的比较，证明了二次预应力组合结构可大大改善反拱过大等问题，值得进一步推广。 通过编制程序进行数值分析和试验验证两种方法研究了二次预应力组合结构与常规预应力结构在使用阶段的一些差异，并对这些差别及其变化规律加以描述。另外通过与常规预应力结构的比较，研究了二次预应力组合结构正截面承载能力和结构变形的计算方法，为今后的设计和研究提供了参考。 最后在总结全文的基础上提出了以后还有待于进一步解决的问题。更多还原

【Abstract】 To deal with the great reversed deflection in the procedures of tension or creep of ultra thin beam bridge, a new structure, that is the double pre-stressed composite structure, is put forward in this thesis. A lot of studies are made on its performance and characteristic in construction, creep and use phase, from both theoretical analysis and experimental study.The idea about the double pre-stressed composite structure is coming from the development of ultra thin beam, combining with the problems in engineering practices and other existing pre-stressed structures’ characteristics. In this thesis, the primary principles and construction technology of double pre-stressed composite structure are based on the introduction of operation of experiment.Then, focusing on the construction technology of double pre-stressed composite structure, the structure analysis methods in this phase is introduced. Compared with normal pre-stressed structures in experiments, this new structure characteristics and virtues are listed to support its application values and popularize prospect. Further more, some factors, which may affect those characteristics, are full investigated.Based on the linear creep theory and deformation coordination principle, the calculation method and computing formulas about the redistribution of stress are brought forward, and its effect factors are investigated in this thesis. Compared with the normal pre-stressed structures, it is proved that its effect factors can effectively decrease the reverse deflection and its application values.The numerical method, which uses the program and experimental validation are employed to research the differences, which is summing up later, between the double pre-stressed composite structure and the normal ones. After that, the calculation method about double pre-stressed composite structure’s bearing capability and deflection are investigated, which provide the consults to future research and design works.Finally, on the basis of summarizing full thesis, several questions still required more studies are put forwards.更多还原