高墩多跨连续刚构桥高墩刚度匹配问题研究

发布时间：2018-01-05 02:29

本文关键词：高墩多跨连续刚构桥高墩刚度匹配问题研究　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：连续刚构桥呈现跨径增大、跨数增多、墩高增加的趋势,当墩的高度存在较大的高度差的情况下,在外荷载作用下,墩、梁的内力呈现不均衡性,尤其是由于混凝土收缩徐变、温度作用、基础不均匀沉降等将对整个结构带来较大的不均衡次内力。连续刚构桥墩梁固结,当上部结构参数确定时,墩间相对刚度不同对结构内力分布及变形产生较大的影响,合理的高墩刚度匹配能使结构受力更为合理。文中以咸旬高速公路三水河特大桥为工程背景,首先,运用有限元程序对不同高墩刚度匹配的结构进行分析研究,通过比较分析寻找出影响结构内力及变形的关键因素;然后,结合多跨连续刚构桥墩的刚度匹配基本原则,对高墩刚度匹配进行分析研究,进而为墩的刚度匹配优化设计提供有益的参考。主要完成了以下工作:1、总结了近年来高墩刚度匹配相关基本计算方法及理论研究成果,分析并总结了墩刚度对连续刚构桥内力及变形的影响。2、对高墩常用的结构类型进行总结对比分析,对不同类型墩的刚度进行了比较;并对不同类型高墩建立抗推刚度计算模型及对高墩抗推刚度计算方法分析总结,同时分析了高墩抗推刚度影响因素。3、对不同墩位高墩刚度改变,外荷载作用下,结构内力及墩顶位移的变化规律进行比较分析,发现距离中跨跨中越远墩刚度变化对结构内力及位移产生的影响越大。4、比较不同荷载工况下,改变墩的刚度时,连续刚构桥内力及位移的影响敏感度,通过比较分析得出:不同高墩刚度匹配情况下,恒荷载对连续刚构桥内力及位移影响敏感性较小;系统温度变化及混凝土收缩徐变对结构内力及变形影响较大。5、以主墩内力及应力为控制目标,对结构对称、不同跨数连续刚构桥墩的刚度匹配进行分析研究,分析不同刚度匹配下,墩顶、墩底处内力及应力变化规律,通过分析得出:对于对称的偶数跨连续刚构桥,中墩刚度可与其余墩刚度任意比例匹配;对于墩高相差不大的奇数跨连续刚构桥,在保证结构强度及稳定的同时,相邻的靠近边跨侧墩与靠近中跨侧墩的刚度比在1:6~1:7左右为宜,且随跨径比不同,合理墩间刚度比不同;当边中墩高度在达到0.5时,合理墩间刚度比在1:4左右,将边墩设计成抗推刚度较小的双肢墩对结构受力更有利。
[Abstract]:Continuous rigid frame bridge presents the tendency of increasing span, increasing span number and increasing pier height. When the height of pier exists a large height difference, under external load, the internal force of pier and beam is unbalanced. Especially because of the shrinkage and creep of concrete, temperature and uneven settlement of foundation, etc. Continuous rigid frame bridge pier beam consolidation, when the superstructure parameters are determined. The difference of relative stiffness between piers has a great influence on the distribution and deformation of the internal force of the structure. Reasonable matching of the stiffness of the high pier can make the force of the structure more reasonable. In this paper, taking the Xian-ten-day Expressway Sanshui River Bridge as the engineering background, first of all. The finite element program is used to analyze and study the structures with different stiffness matching of high piers, and the key factors affecting the internal force and deformation of the structure are found through the comparative analysis. Then, combined with the basic principle of stiffness matching of multi-span continuous rigid frame bridge pier, the stiffness matching of high pier is analyzed and studied, which provides a useful reference for the optimization design of pier stiffness matching. This paper summarizes the basic calculation methods and theoretical research results of the high pier stiffness matching in recent years, and analyzes and summarizes the influence of pier stiffness on the internal force and deformation of continuous rigid frame bridge. 2. The common structural types of high piers are summarized and analyzed, and the stiffness of different types of piers are compared. The calculation model of anti-pushing stiffness and the calculation method of anti-pushing stiffness of high pier are established for different types of high pier. At the same time, the factors affecting the anti-pushing stiffness of high pier are analyzed, and the stiffness of high pier in different positions is changed. Under the action of external load, the changes of internal force and displacement of pier top are compared and analyzed. It is found that the variation of pier stiffness in the middle span of middle span has greater influence on the internal force and displacement of the structure. By comparing the sensitivity of internal force and displacement of continuous rigid frame bridge under different load conditions and changing the stiffness of pier, it is concluded that: different high pier stiffness match. The influence of constant load on the internal force and displacement of continuous rigid frame bridge is less sensitive. The change of system temperature and shrinkage and creep of concrete have great influence on the internal force and deformation of the structure. 5. Taking the internal force and stress of the main pier as the control target, the structure is symmetrical. The stiffness matching of the pier of continuous rigid frame bridge with different span number is analyzed and the internal force and stress changes at the top and bottom of the pier under different stiffness matching are analyzed. The results show that: for symmetrical even span continuous rigid frame bridge. The stiffness of the middle pier can be matched with the stiffness of the other piers in any proportion. For the odd span continuous rigid frame bridge with little difference in pier height, the stiffness ratio of adjacent side span pier and near middle span side pier is about 1: 6 or 1: 7, while the structural strength and stability are guaranteed. The reasonable stiffness ratio between piers is different with different span ratio. When the height of the middle pier reaches 0.5 and the reasonable ratio of stiffness between the piers is about 1: 4, it is more favorable to design the side pier as a two-legged pier with low pushing stiffness.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.23

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