先简支后连续T梁桥极限承载力与动力响应研究

发布时间：2018-08-29 07:34

【摘要】：先简支后连续梁桥具备简支梁桥和连续梁桥的优点,应用日趋广泛,然而人们对该种桥型的极限承载力和车桥动力相互作用引起的桥梁和车辆的动力响应了解较少。因此,深入研究先简支后连续预应力混凝土梁桥的极限承载力以及车桥动力相互作用引起的桥梁和车辆的动力响应,对于该桥梁体系的发展及合理利用具有较大的理论意义和实用价值。本文以河南省省道S318线某大桥——先简支后连续预应力混凝土T形梁桥(以下简称先简支后连续预应力混凝土T梁桥)为工程实例,对其受力及破坏机理、极限承载力、车桥耦合振动、冲击系数和汽车在桥上运行舒适性开展了研究,完成的主要研究工作如下:1)采用Midas/FEA有限元软件建立大桥的三维实体有限元计算模型,考虑材料非线性,计算分析了其在不同工况下结构的破坏形态、破坏荷载以及桥梁安全系数等,了解了该桥型的破坏特征。2)对先简支后连续预应力混凝土T梁桥进行了加载全过程模拟,得到了该桥型的极限承载力;研究了成桥初始状态的内力,探讨了施工工艺对桥梁极限承载力的影响。3)提出了先简支后连续预应力混凝土梁桥的动力分析模型,将桥梁和车辆看作为一个整体时变系统,采用自编程序计算了桥梁的有载频率和振型,对比分析了桥梁有载频率和无载频率的区别,在此基础上,讨论了汽车的轮胎刚度、悬架刚度、簧下质量和簧上质量等对桥梁有载频率的影响。4)计算了车桥时变系统的动力响应及桥梁的位移冲击系数,讨论了车辆数目、车辆间距、不同车道、车速和路面粗糙度等因素对车桥时变系统动力响应及桥梁冲击系数的影响;通过车桥振动耦合分析,评价了汽车运行于先简支后连续预应力混凝土T梁桥上时的行驶舒适性,分析了车速和路面粗糙度对汽车行驶舒适性的影响。
[Abstract]:Simple supported and then continuous beam bridges have the advantages of simple supported beam bridges and continuous beam bridges, and are widely used. However, little is known about the ultimate bearing capacity of this type of bridge and the dynamic response of bridges and vehicles caused by the dynamic interaction between vehicle and bridge. Therefore, the ultimate bearing capacity of simply supported and then continuous prestressed concrete beam bridges and the dynamic responses of bridges and vehicles caused by vehicle-bridge dynamic interaction are deeply studied. It is of great theoretical significance and practical value for the development and rational utilization of the bridge system. In this paper, a bridge on S318 line of Henan Provincial Road, which is simply supported and then continuous prestressed concrete T-beam bridge (hereinafter referred to as simply supported and then continuous prestressed concrete T-beam bridge), is taken as an engineering example, and the ultimate bearing capacity and the failure mechanism of the bridge are discussed. The coupling vibration, shock coefficient and vehicle comfort on the bridge are studied. The main research work is as follows: 1) the three-dimensional finite element model of the bridge is established by using Midas/FEA finite element software, and the material nonlinearity is taken into account. The failure mode, failure load and bridge safety factor of the bridge under different working conditions are calculated and analyzed. The failure characteristics of the bridge type .2) are simulated in the whole loading process of the prestressed concrete T-beam bridge with simple support and continuous prestressed concrete. The ultimate bearing capacity of the bridge is obtained, the internal force of the initial state of the bridge is studied, and the influence of construction technology on the ultimate bearing capacity of the bridge is discussed. Considering the bridge and vehicle as an integral time-varying system, the loaded frequency and vibration mode of the bridge are calculated by using self-compiled program, and the differences between the loaded frequency and the no-load frequency of the bridge are compared and analyzed. On the basis of this, the tire stiffness of the automobile is discussed. The influence of suspension stiffness, underspring mass and spring mass on the loaded frequency of the bridge is calculated. The dynamic response of the time-varying system and the displacement impact coefficient of the bridge are calculated. The number of vehicles, the distance between vehicles, the different driveways are discussed. The influence of vehicle speed and road roughness on the dynamic response of time-varying system and the impact coefficient of the bridge is discussed, and the ride comfort of the vehicle running on the prestressed concrete T-beam bridge with simple support and continuous prestressed concrete beam is evaluated through the vibration coupling analysis of the vehicle and bridge. The influence of vehicle speed and road roughness on vehicle driving comfort is analyzed.
【学位授予单位】：郑州大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U441

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