桥梁伸缩装置损伤分析和选型应用

发布时间：2018-04-21 07:37

本文选题：桥梁 + 伸缩装置　；参考：《华南理工大学》2014年硕士论文

【摘要】：伸缩装置作为桥梁结构的重要构件之一，主要承受车轮荷载的冲击作用，且长时间裸露于大气中，使用环境极其恶劣，容易发生破坏且维修更换困难。因此，分析研究伸缩装置在车辆疲劳荷载作用下的损伤，对延长伸缩装置的使用寿命及为维修更换提供建议具有一定的实践意义。本文在总结模数式伸缩装置的主要病害为锚固系统和承重体系的疲劳破坏的基础上，得出车辆疲劳荷载是导致伸缩装置损坏的主要原因；以广东某大桥SD-160模数式伸缩装置破坏为例，通过对该大桥车流量调查，建立了5种不同类型的简化车辆荷载频值谱；采用ANSYS有限元软件对伸缩装置的中梁钢进行载荷分析，，并估算了锚固区混凝土、锚固钢筋与预埋钢筋焊接点和中梁钢三个部位危险点的疲劳使用寿命，结果表明锚固区混凝土使用寿命为7.7年，最先达到破坏；中梁钢在只考虑车辆载荷作用下的疲劳使用寿命为29.3年，预埋钢筋焊接点疲劳使用寿命为10.7年。然后分析了影响伸缩装置疲劳使用寿命的三个主要因素，结果表明，当支撑横梁间距增大时，中梁钢的使用寿命减小；锚固区混凝土强度越大，混凝土本身使用寿命和预埋钢筋焊接点使用寿命都随之增大；当用弹性树脂混凝土进行锚固时使用寿命约为C50混凝土使用寿命的两倍，C40钢纤维混凝土与C50混凝土锚固时的使用寿命相当。对该大桥SD-160伸缩装置更换施工方案疲劳损伤分析，估算其使用寿命为6.2年，论文作者提出的建议方案Ⅰ比原施工方案可以延长中梁钢焊接点使用寿命1.5年，建议方案Ⅱ使用寿命可达20.8年，同支撑横梁间距为1.8m时中梁钢危险点疲劳使用寿命相当，研究成果可为类似伸缩装置更换工程参考借鉴。
[Abstract]:As one of the important components of bridge structure, the telescopic device is mainly subjected to the impact of wheel load, and exposed to the atmosphere for a long time, the environment is extremely bad, easy to damage and difficult to repair and replace. Therefore, it is of practical significance to analyze and study the damage of the telescopic device under the action of vehicle fatigue load to prolong the service life of the telescopic device and to provide advice for the maintenance and replacement of the telescopic device. Based on the conclusion that the main diseases of modular telescopic device are the fatigue failure of anchoring system and load-bearing system, it is concluded that the fatigue load of vehicle is the main cause of the damage of the expansion and expansion device. Taking the failure of SD-160 modulus telescopic device of a Guangdong bridge as an example, five different types of simplified vehicle load frequency spectrum are established by investigating the traffic flow of the bridge, and the load analysis of the middle girder steel of the telescopic device is carried out by using ANSYS finite element software. The fatigue service life of concrete in Anchorage zone, welding point of anchoring steel bar and steel in the middle beam is estimated. The results show that the service life of concrete in Anchorage zone is 7.7 years, and the failure is the first. The fatigue service life of middle beam steel is 29.3 years under the action of vehicle load only, and the fatigue life of welding joint of embedded steel bar is 10.7 years. Then, three main factors affecting fatigue life of the extension device are analyzed. The results show that the service life of the steel decreases with the increase of the spacing of the bracing beam, and the strength of the concrete in the Anchorage zone increases. Both the service life of concrete itself and the service life of welding joint of embedded steel bar increase with it. When anchoring with elastic resin concrete, the service life of C40 steel fiber reinforced concrete is about twice as long as that of C50 concrete, and the service life of C40 steel fiber reinforced concrete is the same as that of C50 concrete. According to the fatigue damage analysis of the replacement construction scheme of SD-160 expansion device of the bridge, the service life of the bridge is estimated to be 6.2 years. The author's proposal I can prolong the service life of the steel welding joint of the middle beam by 1.5 years compared with the original construction plan. It is suggested that the service life of scheme II can be up to 20.8 years, and the fatigue life of the steel dangerous point of the middle beam is equivalent when the distance between the supporting beam and the beam is 1.8 m. The research results can be used for reference in the replacement of similar telescopic devices.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U443.31

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