半整体式无缝桥性能分析

发布时间：2018-05-30 16:00

本文选题：半整体式无缝桥 + 温度　；参考：《长安大学》2014年硕士论文

【摘要】：伸缩装置长期暴露在大气中极易遭到破坏，修复需耗费大量的人力和物力，如果增加桥跨连续长度减少伸缩装置数量或直接取消伸缩装置，不仅大大降低桥梁的造价以及养护维修的巨额费用，而且可减小对桥梁的冲击，提高行车舒适性。整体式无缝桥应运而生，但已建的整体式无缝桥在运营过程中出现了各种问题，为解决这些问题，有学者提出了性能更优的半整体式无缝桥。本文以一座（5×25）m的先简支后连续梁桥为实例，自行设计了半整体式桥台，利用Midas Civil建立三维有限元模型，上部结构采用弹性空间梁格模拟，台后土和桩侧土抗力采用节点弹性支承模拟，支座采用线性弹簧模拟。对半整体式无缝桥的受力性能展开了以下研究：首先分析了均匀温度、截面温度梯度以及收缩徐变对上部结构内力和变形的影响，分析结果表明升温对主梁弯矩、主梁轴力和主梁纵向位移影响较大，收缩徐变对主梁纵向和竖向位移、主梁轴力影响较大，，对桥台桩的弯矩影响较大。其次按照现行规范对该半整体式无缝桥进行了持久状况承载能力极限状态和正常使用极限状态验算，对主梁进行了持久状况应力分析验算。对无缝桥的应力验算有别于传统梁式桥，应考虑温度轴向压应力的影响以保证结构安全性。然后对半整体式无缝桥的重要设计参数进行了分析，参数主要包括温度、背墙高度、背墙与主梁抗弯刚度比（背墙厚度）及地基土比例系数（台后土刚度），并给出了关键参数的设计合理取值建议。最后指出了半整体式无缝桥设计和施工应注意的事项，对半整体式无缝桥的后续研究及其在中国的开发应用具有一定的参考价值。
[Abstract]:Telescopic devices are extremely vulnerable to damage when exposed to the atmosphere for a long time, and repair requires a great deal of manpower and material resources. If the number of telescopic devices is reduced by increasing the continuous length of the bridge span or directly canceling the telescopic devices, Not only the cost of bridge and the huge cost of maintenance and repair can be greatly reduced, but also the impact on the bridge can be reduced, and the driving comfort can be improved. Integral seamless bridge emerged as the times require, but there are a variety of problems in the operation of the built integrated seamless bridge. In order to solve these problems, some scholars have proposed a better performance of semi-integral seamless bridge. In this paper, a simple supported and continuous beam bridge with 5 脳 25m is taken as an example. The semi-integral abutment is designed by itself. The three-dimensional finite element model is established by Midas Civil, and the upper structure is simulated by elastic space beam lattice. The resistance of soil behind abutment and pile side is simulated by elastic support and linear spring. The mechanical properties of the semi-integral seamless bridge are studied as follows: firstly, the effects of uniform temperature, cross-section temperature gradient and shrinkage and creep on the internal force and deformation of the superstructure are analyzed. The results show that the temperature rise affects the bending moment of the main beam. The axial force of the main beam and the longitudinal displacement of the main beam have a great influence on the longitudinal and vertical displacement of the main beam, the axial force of the main beam and the bending moment of the abutment pile. Secondly, according to the current code, the ultimate state of bearing capacity and the limit state of normal use of the semi-integral seamless bridge are checked, and the stress analysis of the main beam is carried out. The stress checking calculation of the seamless bridge is different from that of the traditional beam bridge. The influence of temperature axial compression stress should be considered to ensure the safety of the structure. Then the important design parameters of semi-integral seamless bridge are analyzed. The parameters mainly include temperature, back wall height, The ratio of flexural stiffness (thickness of back wall) and the ratio coefficient of foundation soil (soil stiffness behind abutment) between the back wall and the main beam are given, and some suggestions for the design of the key parameters are given. Finally, the paper points out the matters needing attention in the design and construction of the semi-integral seamless bridge, which has certain reference value for the follow-up study of the semi-integral seamless bridge and its development and application in China.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U442.5

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