车辆荷载运营状态对预应力简支梁桥的疲劳性能影响研究

发布时间：2018-05-15 09:50

本文选题：预应力混凝土简支梁 + 运营状态　；参考：《长沙理工大学》2014年硕士论文

【摘要】：随着交通运输求的急剧扩增,为了追求利益和效率最大化,车辆运营状态呈现出车流量大、超速和超载超限严重等特征。服役期桥梁长期处于高频和高应力幅的交变荷载作用下,导致桥梁疲劳寿命急剧缩减。因此,车辆运营状态对桥梁的疲劳性能的影响的研究意义重大。本文基于有限元理论和实测交通统计数据,研究内容如下：(1)总结了预应力混凝土结构的疲劳损伤理论。(2)以实际车辆模型为研究对象,运用刚性梁学法,计算多轴车辆不同超载率下车辆轴荷的分配比例。在此基础上,通过有限元模型分析了5种代表性车辆在不同超载率下对预应力简支梁桥的疲劳损伤的影响。最后,推导多轴车辆超载率与简支梁桥的疲劳损伤倍数关系式。(3)分析了多轴车辆行车车速、行车间距、连续车流和桥梁跨径等参数对预应力简支梁桥疲劳性能的影响。并提出了考虑多车同时上桥时,桥梁的疲劳累计损伤公式。车速对桥梁疲劳性能的影响源于车速对动力系数的改变。车速对桥梁结构的疲劳损伤影响不是呈线性增长的,在一定范围内出现峰值。其他条件相同的情况下,连续车流量越大,车流对桥梁造成的疲劳损伤值越小。桥梁跨径对疲劳损伤的影响,除了本身截面设计特征值以外,与车辆轴距分布密切相关。(4)基于WIM(动态称重系统),统计得到了宜泸高速南溪路段交通量数据,分析了该路段车辆分布类型及比例、各车型的行车车速、实时交通流量、车辆总重以及各轴轴重。运用高斯混合模型描述各车辆类型的总重和轴重概率分布,并计算得出宜泸高速6种的标准疲劳车辆模型。在此基础上,对宜泸高速某预应力简支梁桥进行了疲劳寿命评估。
[Abstract]:With the rapid expansion of traffic and transportation, in order to maximize the benefits and efficiency, the vehicle operating state presents the characteristics of large traffic, overspeed and serious overload. The bridge fatigue life of the service period is reduced sharply because of the high frequency and high stress amplitude under the alternating load for a long time. Therefore, it is of great significance to study the influence of vehicle operation state on the fatigue performance of bridges. Based on the finite element theory and traffic statistics, the research contents are as follows: (1) the fatigue damage theory of prestressed concrete structures is summarized. (2) taking the actual vehicle model as the research object, the rigid beam method is used. The distribution ratio of axle load of multi-axle vehicle with different overload ratio is calculated. On the basis of this, the influence of five representative vehicles on the fatigue damage of prestressed simply supported beam bridge under different overloading rates is analyzed by finite element model. Finally, the relationship between the overloading ratio of multi-axle vehicles and fatigue damage multiple of simply supported beam bridges is derived. The effects of multi-axle vehicle driving speed, driving distance, continuous traffic flow and bridge span on the fatigue performance of prestressed simply supported beam bridges are analyzed. The fatigue cumulative damage formula of the bridge is presented when multiple vehicles are taken into account at the same time. The influence of speed on the fatigue performance of bridge is due to the change of speed to dynamic coefficient. The effect of speed on fatigue damage of bridge structure is not linearly increased, and the peak value appears in a certain range. When other conditions are the same, the fatigue damage value of the bridge caused by the traffic flow is smaller with the increase of the continuous traffic flow. The influence of bridge span on fatigue damage is closely related to the vehicle wheelbase distribution in addition to the design eigenvalue of its own section. Based on WIM-based dynamic weighing system, traffic volume data of Nanxi section of Yi-Lu-expressway are statistically obtained. The distribution type and proportion of vehicles, driving speed, real time traffic flow, total vehicle weight and axle load of each vehicle are analyzed. The Gao Si hybrid model is used to describe the probability distribution of total weight and axle weight of each vehicle type, and six kinds of standard fatigue vehicle models for Yilu High Speed are calculated. On this basis, the fatigue life of a prestressed simply supported beam bridge is evaluated.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.4

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