公路大跨度预应力混凝土连续刚构桥长期变形的预测
发布时间：2018-11-06 16:36
【摘要】：近年来,大跨径预应力混凝土连续刚构桥普遍出现跨中下挠严重且持续发展的现象,日益威胁桥梁结构的安全性与行车舒适性。因此,明确结构产生过度下挠的实质成为当前此类桥型急需解决的课题。国内外相关研究表明,引发大跨径预应力混凝土连续刚构桥跨中长期下挠过大的一个重要原因,是由于混凝土材料自身存在较大的随机性,进而导致传统的确定性设计方法在计算成桥后长期变形时与实际情况有很大的差异。对于此类问题,有必要采用随机方法对其进行研究。综上所述,本文通过结合某公路大跨径预应力混凝土连续刚构桥工程实例,在确定性分析的基础上采用随机分析方法,并将影响主梁长期变形的几类不确定性因素考虑在内,对大跨径预应力混凝土连续刚构桥的跨中长期变形进行概率层面上的分析预测工作。本文主要研究内容包括：(1)简单概括大跨径预应力混凝土连续刚构桥长期下挠成因的发展历程和研究成果,列举国内外主流的混凝土收缩徐变理论模型,结合收缩徐变的机理以及收缩徐变的主要影响因素,将响应面技术与Monte Carlo法相结合并应用于结构长期变形的随机分析中,为计算分析工作提供了简明而高效的分析方法。(2)参阅大跨径桥梁静力仿真分析资料,对某公路大跨径预应力混凝土连续刚构桥进行静力条件下的确定性的分析。通过对实例桥的施工过程控制仿真分析,研究结构的施工过程的内力、挠度和应力变化规律。(3)本文提出一个基于Bayesian理论推导的关于混凝土结构长期变形的计算框架,其中涉及到重要抽样技术和基于响应面的Monte Carlo方法,用于提高计算的稳定性以及效率,经数次逐步计算后便能达到有效缩小长期变形预测不确定性的目的。同时通过采用不同的收缩徐变模型条件下的算例来验证该方法的适用性。
[Abstract]:In recent years, the long-span prestressed concrete continuous rigid frame bridge is a common phenomenon of serious and sustainable development of mid-span deflection, which is increasingly threatening the safety and driving comfort of bridge structure. Therefore, it is urgent to solve this kind of bridge at present by clarifying the essence of excessive deflection. Related studies at home and abroad show that the long span prestressed concrete continuous rigid frame bridge caused a long term deflection is due to the large randomness of the material itself. Therefore, the traditional deterministic design method is very different from the actual situation in the calculation of the long term deformation after the bridge is completed. For this kind of problem, it is necessary to use random method to study it. To sum up, combining with the engineering example of a highway long-span prestressed concrete continuous rigid frame bridge, this paper adopts the stochastic analysis method based on deterministic analysis, and takes into account several kinds of uncertain factors that affect the long-term deformation of the main beam. The long-span prestressed concrete continuous rigid frame bridge is analyzed and forecasted on the probability level. The main research contents of this paper are as follows: (1) the development history and research results of long-time deflection of long-span prestressed concrete continuous rigid frame bridge are summarized, and the theoretical models of shrinkage and creep of concrete are listed. Combined with the mechanism of shrinkage and creep and the main influencing factors of shrinkage and creep, the response surface technique and Monte Carlo method are combined and applied to the random analysis of long-term deformation of structures. It provides a simple and efficient analysis method for the calculation and analysis. (2) referring to the static simulation analysis data of long-span bridge, the deterministic analysis of a highway long-span prestressed concrete continuous rigid frame bridge under static condition is carried out. Through the simulation analysis of the construction process control of the concrete bridge, the internal force, deflection and stress of the structure are studied. (3) this paper presents a calculation framework for the long-term deformation of concrete structure based on the Bayesian theory. The important sampling technique and the Monte Carlo method based on response surface are involved to improve the stability and efficiency of the calculation. After several successive calculations, the uncertainty of long-term deformation prediction can be effectively reduced. At the same time, the applicability of the method is verified by examples under different shrinkage and creep models.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.23
本文编号：2314844
[Abstract]:In recent years, the long-span prestressed concrete continuous rigid frame bridge is a common phenomenon of serious and sustainable development of mid-span deflection, which is increasingly threatening the safety and driving comfort of bridge structure. Therefore, it is urgent to solve this kind of bridge at present by clarifying the essence of excessive deflection. Related studies at home and abroad show that the long span prestressed concrete continuous rigid frame bridge caused a long term deflection is due to the large randomness of the material itself. Therefore, the traditional deterministic design method is very different from the actual situation in the calculation of the long term deformation after the bridge is completed. For this kind of problem, it is necessary to use random method to study it. To sum up, combining with the engineering example of a highway long-span prestressed concrete continuous rigid frame bridge, this paper adopts the stochastic analysis method based on deterministic analysis, and takes into account several kinds of uncertain factors that affect the long-term deformation of the main beam. The long-span prestressed concrete continuous rigid frame bridge is analyzed and forecasted on the probability level. The main research contents of this paper are as follows: (1) the development history and research results of long-time deflection of long-span prestressed concrete continuous rigid frame bridge are summarized, and the theoretical models of shrinkage and creep of concrete are listed. Combined with the mechanism of shrinkage and creep and the main influencing factors of shrinkage and creep, the response surface technique and Monte Carlo method are combined and applied to the random analysis of long-term deformation of structures. It provides a simple and efficient analysis method for the calculation and analysis. (2) referring to the static simulation analysis data of long-span bridge, the deterministic analysis of a highway long-span prestressed concrete continuous rigid frame bridge under static condition is carried out. Through the simulation analysis of the construction process control of the concrete bridge, the internal force, deflection and stress of the structure are studied. (3) this paper presents a calculation framework for the long-term deformation of concrete structure based on the Bayesian theory. The important sampling technique and the Monte Carlo method based on response surface are involved to improve the stability and efficiency of the calculation. After several successive calculations, the uncertainty of long-term deformation prediction can be effectively reduced. At the same time, the applicability of the method is verified by examples under different shrinkage and creep models.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.23
【参考文献】
相关期刊论文 前4条
1 张建仁;汪维安;余钱华;;高墩大跨连续刚构桥收缩徐变效应的概率分析[J];长沙交通学院学报;2006年02期
2 李远瑛;张德生;;基于响应面和蒙特卡罗法结构位移可靠度[J];辽宁工程技术大学学报(自然科学版);2011年03期
3 向天宇;童育强;赵人达;;基于退化梁单元的混凝土结构徐变分析[J];工程力学;2006年04期
4 杨志平,朱桂新,李卫;预应力混凝土连续刚构桥挠度长期观测[J];公路;2004年08期
，本文编号：2314844
本文链接：https://www.wllwen.com/kejilunwen/daoluqiaoliang/2314844.html
