考虑随机交通流参数联合分布的连续刚构桥试验荷载研究

发布时间：2018-02-01 12:23

  本文关键词： 连续刚构 联合概率分布 交通流新特性 静力荷载试验 车辆荷载模型 效应调整系数　出处：《西安建筑科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着我们国家交通事业的飞速发展和国民经济建设的迫切需要,公路桥梁的交通流量不断加大,而且各种车辆超载运输现象日益严重,对公路桥梁的承载能力和通行能力要求更高,这也使得部分公路桥梁存在不少的潜在安全隐患问题。因此,这引起了人们对公路桥梁安全性能评估与鉴定的普遍关注,而荷载试验是进行桥梁结构整体承载能力评定的主要手段。大跨径连续刚构桥作为一种既跨越能力强又非常经济而且行车舒适的桥梁型式,在陕西省乃至西部山区则将其作为跨越深沟峡谷的首选桥型,在特大桥数量中占有统治地位。然而,交通流在公路桥梁,尤其是在大跨径连续刚构桥梁上的分布特性与一般道路路线上存在着显著的差异(如车辆跟驰,轻、重车流分车道渠化行驶,重载车辆不在桥梁跨度范围内超车等特性)。因此,车辆荷载在桥梁上的相关参数量值确定时,应重点结合大跨径连续刚构桥使用阶段车辆运营的特殊性,考虑其联合概率分布,即桥梁上的交通流新特性。进而,本文基于公路桥梁随机交通流新特性,开展了大跨径连续刚构桥试验荷载研究。目前应用最广泛、最主要的评定桥梁结构受力性能的荷载试验方法为静力荷载试验,所以桥梁结构的静载试验是主要的研究对象。易知,桥梁静力试验的核心内容为设计控制计算和试验荷载。而且控制荷载和试验荷载均是以车辆为主要活荷载,故研究桥梁试验荷载的关键就是对于车辆荷载的研究。本文针对陕西西禹高速公路典型路段进行实际交通流车辆荷载的调查和统计分析,并借助蒙特卡罗模拟方法、MATLAB语言编程和联合随机变量抽样序列产生方法,建立了车重与车头间距参数联合分布的连续刚构桥随机车辆荷载模型。选取四座大跨径连续刚构桥,考虑所建立的车辆荷载模型,计算其各控制截面的最不利效应值,依据《公路桥梁承载能力检测评价规程》建议的静载试验加载效率,得出各桥跨各控制截面的试验车辆荷载的效应调整系数,并进行各种工况下的结果对比分析。研究得到的随机交通流参数联合分布大跨径连续刚构桥车辆荷载模型,为大跨径混凝土梁式桥设计荷载的制定和荷载试验检测评定提供了一定的参考。另外,研究得出的控制截面试验荷载效应调整系数,有助于对试验车辆荷载作合理的调整,然后进行更加符合实际交通流特性的桥梁结构荷载试验。因此,得到较为客观可信的安全鉴定结果,从而有利于后期针对性的采取措施进行桥梁结构的养护、维修或加固,确保桥梁的安全运营。
[Abstract]:With the rapid development of national transportation and the urgent need of national economic construction, the traffic flow of highway and bridge is increasing, and the phenomenon of overloading of various vehicles is becoming more and more serious. The load carrying capacity and traffic capacity of highway bridges are required to be higher, which also makes some highway bridges have a lot of potential safety problems. This has aroused widespread concern about the evaluation and appraisal of highway and bridge safety performance. Load test is the main method to evaluate the overall bearing capacity of bridge structure. The long-span continuous rigid frame bridge is a type of bridge with strong span capacity, economy and comfortable driving. In Shaanxi Province and even in the western mountainous area, it is the first choice bridge type to cross deep gully canyon, occupies the dominant position in the large bridge quantity. However, the traffic flow is in the highway bridge. Especially in the long-span continuous rigid frame bridge, there is a significant difference between the distribution characteristics and the general road route (such as car-following, light, heavy traffic flow driveway canalization. Heavy duty vehicles are not overtaking within the span of bridges. Therefore, when determining the relative parameters of vehicle loads on bridges, the particularity of vehicle operation in the use phase of long-span continuous rigid frame bridges should be taken into account. Considering the joint probability distribution, that is, the new characteristics of traffic flow on the bridge, this paper, based on the new characteristics of random traffic flow of highway bridge, carries out the experimental load research of long-span continuous rigid frame bridge. At present, it is the most widely used. The most important load test method to evaluate the behavior of bridge structure is static load test, so the static load test of bridge structure is the main research object. The design control calculation and test load are the core contents of the static test of the bridge, and the control load and the test load are the main live load of the vehicle. Therefore, the key to study the bridge test load is to study the vehicle load. This paper carries out the investigation and statistical analysis of the actual traffic flow vehicle load on the typical section of Xiyu Expressway in Shaanxi Province. With the help of Monte Carlo simulation method, MATLAB language programming and joint random variable sampling sequence generation method. The random vehicle load model of continuous rigid frame bridge with the joint distribution of vehicle weight and headspace parameters is established. Four long-span continuous rigid frame bridges are selected and the vehicle load model is considered. The most adverse effect value of each control section is calculated, and the loading efficiency of static load test is suggested according to the "Highway Bridge bearing capacity Test Evaluation procedure". The effect adjustment coefficient of vehicle load of each bridge span and control section is obtained. The vehicle load model of the continuous rigid frame bridge with long span is obtained by comparing and analyzing the results under various working conditions. It provides a certain reference for the design load formulation and load test test evaluation of long-span concrete beam bridge. In addition, the load effect adjustment coefficient of the control section test is obtained. It is helpful to adjust the load of the test vehicle reasonably, and then to carry out the load test of bridge structure more in line with the actual traffic flow characteristics. Therefore, more objective and credible safety appraisal results are obtained. Therefore, it is beneficial to take measures to maintain, repair or reinforce bridge structure in the later stage, and to ensure the safe operation of bridge.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U446
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本文编号：1481851