钢筋混凝土梁承载能力的动力试验法预测研究-桥梁与隧道工程专业论文.docxVIP

摘 要 本文主要针对钢筋混凝土梁(板梁)应用动力法评估承载能力的问题作 了一些研究工作。根据四片板梁模型从完整到破坏不同荷载等级作用下室内 静、动力试验成果，并结合桥梁结构动力学理论，应用非线性回归方法，建 立起板梁静、动刚度比(B)与频率比(a)的经验关系式，进而可以根据 得到的经验公式来评估钢筋混凝土单梁的结构性能。在文中提出了名义配筋 率(u。。)的概念，并依据《公路桥涵设计规范》(1985)中关于钢筋混凝土 梁在正常使用状态下挠度和裂缝的控制要求以及在承载能力极限状态下强度 控制的要求，反推出三种控制内力的计算公式。同时，把它们表述成名义配 筋率函数的形式，用于梁的承载能力量化评定。 本文的研究为钢筋混凝土模型梁桥承载能力的评定打下了基础，也为今 后桥梁承载能力的快速检测方法的发展提供了理论及试验依据。 关键词：煮量窨劝哩!廑茁控制鸯殆 钢筋混痞至梁 承载6沥 基频 名义配筋率 ＼一／  Abstract The article is mainly focused on the method of assessment on load-carrying capacity of reinforced concrete beam girder(such as single deck beam girdeO using dynamic analysis tools．According to the experimental results which are obtained by dilapidated dynamic test on four model deck beam girder from intact to destroyed，combined with the kinetic theory on bridge structures，the experiential formula between the ratio ofstatic stiffness to dynamic stiffness(B) and the ratio of frequency(a)are founded by aid of non-linear regression method．Further more，we can evaluate the structural capability of single reinforeed concrete beam with the formula mentioned before．Simultaneously,alI those requirements Can be represented as a function of nominal steel percentage (u。一according to the formula of strength,deflection and crack width limit based on the serviceability criterion in the Chinese Design Code(1985)．Thus the load carrying capacity is assessed． The research work has estabiished the foundation of assessment on structural capacity of model bridges and it has provided theoretical and experimental bases for the development of the quick-checking method on bridges’ultimate carrying capacity． Key words：ratio ofstatic stiffness to dynamic stiffness control moment reinforced concrete beam girder load-carrying capacity resonance frequency nominal steel percentage  长安大学硕士学位论文 第一章绪论 1．1 引 言 随着崭新的二十一世纪的到来，我国的交通运输事业已进入了发展高 峰。等级高、病害少的高速公路和性能更加优良，更加适用美观的桥梁不 断的投入运营，对我国交通运输状况的改进起到强大的推动作用。 但是，在公路桥梁行业中，一个更加突出的问题亟待解决。近二十年 来，公路交通量不断增加，公路桥梁负荷日益加重。由于推行拖挂运输和 集装箱运输，故普遍存在公路桥梁通过能力低，承载力不足的问