连续刚构桥施工期墩身稳定性及其可靠性研究

发布时间：2018-02-22 04:09

本文关键词： 连续刚构桥失效模式稳定系数体系可靠度　出处：《长沙理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来预应力混凝土结构刚构桥应用广泛,刚构桥施工期结构墩身失稳失效概率随施工步骤而变化,由于刚构桥施工期结构失效概率要大于统一标准规定的服役期失效概率,因此研究连续刚构桥梁施工期体系可靠性具有重要的意义。本文以炎汝高速公路三十三标的黑垅大桥作为现实工程背景,对高墩大跨刚构桥施工过程中的最大悬臂阶段与成桥阶段进行墩身稳定性和可靠性研究,本文具体工作如下：(1) 按照我国现行规范界定的工程结构的承载力极限状态与正常使用极限状态方程,论述了工程结构可靠度的基础概念与工程结构系统可靠度的分析方法,通过计算分析的工程结构可靠指标,比对了一次二阶矩方法(FOSM)与响应面方法(RSM)的计算精度。(2) 对工程结构系统的失效模式进行了探讨,简要的介绍了结构串联系统、结构并联系统和结构串-并联系统。分析了宽界限方法和窄界限方法的上下界和概率网络估算技术方法等工程结构的可靠性评估方法的优缺点。(3) 叙述了工程结构第一类与第二类稳定问题的基本理论,提出现实工程结构稳定问题大多数为第二类稳定问题,使用大型有限元分析软件Midas/Civil对黑垅大桥创建最高悬臂阶段和成桥阶段的空间有限元模型来进行黑垅大桥的稳定性分析,同时工况考虑了风荷载效应、挂篮跌落和日照温差效应等荷载的影响,得出各荷载工况下对桥梁稳定性的影响情况。(4) 按照高墩大跨刚构桥不同施工过程抗力和荷载的相关性,创建高墩大跨刚构桥基于随机过程模型在失稳失效形式下的功能函数,论述了桥梁结构失效模式的寻找和体系可靠度的计算过程,探讨了工程结构抗力、恒载和活载施工过程荷载作用随机性,由实桥模型的计算分析表明了该方式能够有效分析连续刚构桥悬臂施工过程墩身可靠性,分析结果对实际工程结构的可靠性分析有一定的研究参考意义。
[Abstract]:In recent years, prestressed concrete rigid frame bridge has been widely used. The failure probability of pier body of rigid frame bridge in construction period varies with construction steps, because the failure probability of rigid frame bridge during construction period is larger than that of service period failure probability stipulated in uniform standard. Therefore, it is of great significance to study the reliability of continuous rigid frame bridge system during the construction period. In this paper, the Heilong Bridge, which is the subject of 33 Yanru Expressway, is taken as the realistic engineering background. In this paper, the stability and reliability of pier during the construction process of high pier and long span rigid frame bridge are studied, including the maximum cantilever stage and the completion stage. The concrete work of this paper is as follows: (1) according to the limit state equation of carrying capacity and normal use of engineering structure defined in the current code of our country, the basic concept of reliability of engineering structure and the analysis method of reliability of engineering structure system are discussed. The failure modes of engineering structure system are discussed by comparing the calculation accuracy of the first order second moment method (FOSM) with the response surface method (RSM) by calculating and analyzing the reliability index of engineering structure, and the structure series system is introduced briefly. The merits and demerits of the reliability evaluation methods of engineering structures, such as the upper and lower bounds of the wide bound method and the narrow bound method and the probabilistic network estimation technique, are analyzed. The basic theories of the first and second stability problems, It is proposed that the stability problems of practical engineering structures are mostly of the second kind. The stability analysis of the Heilong Bridge is carried out by using the large finite element analysis software Midas/Civil to establish the spatial finite element models of the highest cantilever stage and the completion stage of the Heilong Bridge. At the same time, the effects of wind load, drop of hanging basket and temperature difference of sunlight on the stability of the bridge are considered in the working conditions, and the influence on the stability of the bridge under various load conditions is obtained. The relationship between the resistance and load of the rigid frame bridge with long span with high piers during construction is obtained according to the influence of the load on the stability of the bridge. Based on the stochastic process model, the function function of long-span rigid frame bridge with high piers is established. The search for failure mode of bridge structure and the calculation process of system reliability are discussed, and the resistance of engineering structure is discussed. The randomness of load action during dead load and live load construction shows that this method can effectively analyze the reliability of pier body during cantilever construction of continuous rigid frame bridge by calculation and analysis of real bridge model. The analysis results have certain reference significance for the reliability analysis of practical engineering structures.
【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】：U445.4;U448.23

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