重载铁路大跨度钢桁梁桥顶推施工关键技术分析与监测  

Analysis and Monitoring of Key Technologies in the Incremental Launching Construction of Long-span Steel Truss Bridge on Heavy-haul Railway

作　　者：舒彬[1] 杨超 郝付军[1] Shu Bin;Yang Chao;Hao Fujun(Shaanxi Railway Institute,Weinan 714000,China;China Railway 14th Bureau GroupⅢEngineering Limited,Yanzhou 272100,China)

机构地区：[1]陕西铁路工程职业技术学院,陕西渭南714000 [2]中铁十四局集团第三工程有限公司,山东兖州272100

出　　处：《甘肃科学学报》2019年第6期105-111,共7页Journal of Gansu Sciences

基　　金：陕西高等教育教学改革研究重点攻关项目(17GG008)

摘　　要：为解决大跨度钢桁梁桥顶推关键工况受力状况和变形监测,以黄大重载铁路黄河特大桥连续钢桁梁多点同步顶推施工为例,利用有限元建模计算最大倾覆力,倒退法计算顶推过程中的最不利工况。找出主桁在桥墩支点处最大支反力值以及导梁前端最大变形值和变形规律;计算主桁和导梁在各施工工况下的最大应力值,验算最大受力节点板局部应力值。根据理论计算值,在最不利施工工况设置对应的变形监控点和主要杆件应力监测点。设置顶推系统并计算水平纵向顶推力,测试并记录各顶推工况的启动和运行状态摩擦系数数据。对比理论计算与监测结果发现实测值略小于计算值,施工过程中的材料强度和变形均在安全可靠的储备范围内。有限元分析和施工监测表明:在大跨度平行弦钢桁梁顶推施工过程中采用自重加0.2倍自重的冲击荷载组合是最安全又经济的荷载组合,同时横向纠偏值对主桁应力和纠偏力的影响基本可以忽略。In order to cope with the stress condition and deformation monitoring of the key incremental launching condition of the long-span steel truss bridge,this paper took the multi-point synchronous incremental launching construction of the continuous steel trussed girder of the Huanghe Extra-long Bridge on Huangda Heavy-haul Railway as an example,and used finite element modeling to calculate the maximum overturning force and the retrogressive method to calculate the most adverse conditions in the incremental launching process.The purpose is to find out the maximum support reaction of main girder at the pier fulcrum and the maximum deformation value and deformation law of the front end of the leading-in girder,to calculate the maximum stress value of the main girder and leading-in girder under each construction condition,to prove the local stress value of the maximum force gusset plate.Based on the theoretical calculation value,the deformation monitoring point and the main member stress monitoring point were set in correspondence with the most adverse construction conditions.The incremental launching system was set up and the horizontal longitudinal incremental launching force was calculated and the friction coefficients of start-up and running of each incremental launching condition were measured and recorded.By comparing the results of the theoretical calculation and monitoring,we can see that the measured value is slightly smaller than the calculated value,and the material strength and deformation during construction are within the safe and reliable reserve range.The finite element analysis and construction monitoring indicate that the impact load combination of dead load and 0.2 times of dead load is the safest and most economical in the incremental launching construction process of the long-span parallel string steel truss girder,while the influence of the lateral correction value on the main girder stress and correction force can be basically ignored.

关 键 词：钢桁梁 有限元 监测 顶推系统 纠偏 

分 类 号：U448.35[建筑科学—桥梁与隧道工程] U443.38[交通运输工程—道路与铁道工程]