基于静动力测试的公路PC梁式桥承载能力评定

发布时间：2018-01-19 02:12

本文关键词： 桥梁评定检算分析法荷载试验法承载系数评判区间　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：既有桥梁随着服役时间的增长,部分病害桥梁的承载能力逐年降低,存在巨大的安全隐患,因此利用现有评定技术对既有桥梁的承载能力进行评估,保障桥梁的安全运营,已成为桥梁工作者研究的重点问题。桥梁荷载试验是评定桥梁结构承载能力的重要手段,本文结合公路PC梁式桥的工程特点,基于检算分析法及静动力荷载试验,提出了基于静动力测试的公路PC梁式桥承载能力评定的方法,改进了既有桥梁现行评定指标缺陷及评价体系不完善的问题。本文的主要研究内容及结论如下:1、总结了公路桥梁承载能力评定的常用理论与方法,对各方法的局限性和优点进行了分类阐述;比较了中美桥梁评定规范的异同,明确了美国桥梁评估手册中值得我国现行桥梁评估理论借鉴之处:评定公式可采用等式的形式,以抗力与效应之比呈现承载能力的冗余或欠缺程度;由校验系数确定的检算系数Z_2应调整为由多因素综合确定;评定公式还应考虑系统可靠度。2、结合静动力荷载试验基本理论与方法,讨论了现有评定规程中荷载试验评定指标,详细分析了校验系数的影响因素,指出校验系数存在的不足,即利用校验系数进行评定存在评定结果不精确的问题。3、针对荷载试验评定指标单一、评价体系不完善的问题,基于静动力测试及检算评定理论,提出了承载系数的评定方法及评价指标体系,详细探讨了承载系数指标中各参数的取值,建立了截面抗弯承载系数C_M、拉应力承载系数C_t、压应力承载系数C_c、挠度承载系数C_ω,该方法能量化评定桥梁结构的承载力,反映桥梁结构的活荷载安全储备以及承载能力的利用率。4、基于各承载系数并结合可靠度指标,利用分项权重系数建立了综合承载系数评价指标,并结合公路桥梁养护规范初步划分了综合承载系数的评判区间,量化评价桥梁的承载力和安全性,指导桥梁养护管理工作。5、介绍了本文提出的评定方法的操作流程及综合评判方法,以公路简支板梁桥和连续梁桥为工程实例验证了本文提出的评定方法的可行性与可操作性。
[Abstract]:With the increase of service time, the bearing capacity of some diseased bridges decreases year by year, and there are huge hidden dangers of safety. Therefore, the existing assessment technology is used to evaluate the bearing capacity of existing bridges. Bridge load test is an important means to evaluate the bearing capacity of bridge structure. This paper combines the engineering characteristics of highway PC beam bridge. Based on the analytical method of checking and calculating and static and dynamic load test, a method for evaluating the bearing capacity of highway PC beam bridge based on static and dynamic test is proposed. The main research contents and conclusions of this paper are as follows: 1. The common theories and methods of highway bridge bearing capacity assessment are summarized. The limitations and advantages of each method are classified and expounded. This paper compares the similarities and differences between Chinese and American bridge assessment norms, and clarifies the reference points of the American bridge evaluation manual: the evaluation formula can be in the form of equality. The ratio of resistance to effect shows the degree of redundancy or deficiency of carrying capacity; The checking and calculating coefficient Z _ s _ 2 determined by checking coefficient should be adjusted for multi-factor comprehensive determination; The evaluation formula should also consider the reliability of the system. Combined with the basic theory and method of static and dynamic load test, the evaluation index of load test in the existing evaluation rules is discussed, and the influencing factors of check coefficient are analyzed in detail. The shortcomings of checking coefficient are pointed out, that is, the evaluation result is not accurate by using check coefficient, aiming at the problem that the evaluation index of load test is single and the evaluation system is not perfect. Based on the theory of static and dynamic test and calculation and evaluation, the evaluation method and evaluation index system of bearing coefficient are put forward, and the values of each parameter in the index of bearing coefficient are discussed in detail, and the bending bearing coefficient of section Che M is established. The tensile stress bearing coefficient C _ T, compressive stress bearing coefficient C _ c and deflection bearing coefficient C _ 蠅 can be used to quantitatively evaluate the bearing capacity of bridge structure. It reflects the safety reserve of live load and the utilization ratio of bearing capacity of bridge structure. Based on each bearing coefficient and combined with reliability index, the comprehensive evaluation index of bearing coefficient is established by means of sub-weight coefficient. Combined with the highway bridge maintenance code, the evaluation section of the comprehensive bearing coefficient is preliminarily divided, the bearing capacity and safety of the bridge are quantitatively evaluated, and the bridge maintenance management work is guided. 5. The operation flow and comprehensive evaluation method of the evaluation method proposed in this paper are introduced. The feasibility and maneuverability of the evaluation method proposed in this paper are verified by the engineering examples of simply supported slab girder bridge and continuous beam bridge.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U446

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