在用桥梁汽车荷载效应及限载研究

发布时间：2018-01-12 19:01

本文关键词：在用桥梁汽车荷载效应及限载研究　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国在用桥梁中有相当一部分技术状况欠佳,处于“带病工作”状态,然而公路交通量以及货运量连年增长给本就“伤痕累累”的桥梁带来了更大的安全隐患。对于病害桥梁的维修加固往往是滞后的,进行适当的限载通行可以有效提高结构的安全性能,降低安全隐患。制定限载标准的关键是对在用桥梁实际汽车荷载效应进行合理评估。本文结合《公路桥梁承载能力评定规程》(JTG/T J21-2011)中活载影响修正系数,考虑各影响因素的随机性与等级划分的模糊性,建立在用桥梁汽车荷载效应的随机模糊综合评估系统,并在此基础上建立限载分析的一般流程,为在用桥梁制定合理限载标准。取得的主要成果如下:1)从规范(JTG/TJ21-2011)及相关文献中分离出汽车荷载效应的主要影响因素:车流量、车辆荷载与车辆轴重。讨论影响因素的概率分布特征,并分析各评定指标(Qm/Qd、α、β)的随机特性,证明均不拒绝正态分布。2)为了取值更加合理,在活载修正系数取值时引入模糊数学概念,根据各评定指标(Qm/Qd、α、β)的特点制定相应评价集合,并确定修正指标对于评价集合的隶属函数,建立了各修正系数(ξq1、ξq2、ξq3)的模糊综合评估模型。在此基础上与蒙特卡洛随机模拟相结合,形成了汽车荷载效应的随机模糊综合评估系统。3)在随机模糊综合评估的基础上,将原《公路桥涵设计通用规范》(JTJ021-85)各级汽车车队作为限载模型,以结构的可靠指标作为限载基准,建立在用桥梁的限载评估流程。结果表明,随机模糊综合评估系统能够将交通量及汽车载重量的实际状况考虑在内,既能得到符合当前交通状况的评估结果,也能满足可靠性评估的需要,比规范的确定性评定结果更具有说服力。限载评估实用性较强,能够根据在用桥梁的实际受力状态给出限载指标,为桥梁的安全运行提供依据。
[Abstract]:In our country, quite a few of the bridges are in poor technical condition, and they are in the state of "work with disease". However, the annual increase of highway traffic and freight volume has brought a greater security risk to the already scarred bridges, and the repair and reinforcement of damaged bridges are often lagging behind. The safety performance of the structure can be improved effectively by proper load limiting passage. To reduce the hidden danger of safety, the key to establish the limit standard is to evaluate the actual vehicle load effect of the bridge in use reasonably. In this paper, the rules for evaluating the bearing capacity of Highway Bridges are presented (. JTG/T J21-2011). Considering the randomness of each influencing factor and the fuzziness of grade division, the stochastic fuzzy comprehensive evaluation system of vehicle load effect of bridge is established, and on this basis, the general flow of limited load analysis is established. The main achievements are as follows: 1) from the specification JTG / T J21-2011). The main influencing factors of vehicle load effect are separated from related literature: vehicle flow. The probability distribution characteristics of influencing factors are discussed, and the random characteristics of QM / QD, 伪, 尾 are analyzed. It is proved that the normal distribution. 2) in order to get a more reasonable value, the fuzzy mathematics concept is introduced when the live load correction coefficient is chosen, and according to each evaluation index, Qm / QD, 伪. The characteristics of 尾) make the corresponding evaluation set, and determine the membership function of the revised index for the evaluation set, and establish each correction coefficient (尉 q1, 尉 Q2). Combining with Monte Carlo random simulation, the random fuzzy comprehensive evaluation system of vehicle load effect. 3) is based on the random fuzzy comprehensive evaluation. The original general code for highway bridge and culvert design (JTJ021-85) is taken as the limited load model, and the reliability index of the structure is taken as the limit standard. The results show that the stochastic fuzzy comprehensive evaluation system can take into account the actual traffic volume and vehicle load, and can get the evaluation results that accord with the current traffic conditions. It can also meet the needs of reliability evaluation, which is more convincing than the deterministic evaluation results of the code. The limited load assessment is more practical and can give the limit load index according to the actual stress state of the bridge in use. It provides the basis for the safe operation of the bridge.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441.2

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