摘要
采用横向四滑道步履式顶推的宽幅钢箱梁,其与顶推支撑接触区域的局部受力特性如何缺乏研究,且对能否确保顶推安全与顺利至关重要。以泸州沱江四桥变曲率竖曲线钢箱梁顶推施工为背景,采用通用有限元软件ABAQUS建立典型不利工况下"梁-壳-实-接触"混合有限元模型,对局部受力最不利的L5临时墩滑道处钢箱梁的应力及其对材料参数、施工误差的敏感性进行了分析。结果表明:典型不利工况下滑道处钢箱梁线弹性局部稳定安全系数和应力满足规范要求;无应力状态横向四滑道顶面标高相同,梁底横向标高相同;在钢箱梁自重作用下,横向四滑道支反力不等,内外侧滑道支反力分配比为1.69∶1;垫块在采用设计面积条件下,等效弹模降低至钢材的60%,滑道处钢箱梁局部受力最佳;滑道处钢箱梁主要受力构件应力对横向四滑道顶升不同步、转角偏差较为敏感;竖向顶升高差的安全阈值为±5 mm,外侧钢垫块顶面标高宜比内侧钢垫块顶面标高高2 mm;《公路桥涵施工技术规范》顶推施工轴线偏位的允许值为10 mm,对横向四滑道的钢箱梁顶推施工具有一定的富余度。
The local stress characteristics of the contact area between launching support and wide steel box girder,which constructed by transverse four-slide walking-type incremental launching method,are lacking of research,and the state of local stress is crucial to ensure the safety and smoothness of the launching process.Taking the incremental launching of variable curvature vertical curve steel box girder in Tuojiang Fourth Bridge in Luzhou as the background,a"beam-shell-solid-contact"hybrid finite element model under typical disadvantageous condition is set up by software ABAQUS.The stress of the steel box girder at the L5 temporary pier slideway with the most disadvantageous local force and its sensitivity to the material parameters and the construction error are analyzed.The result shows that(1)The linear elastic local stability coefficient and stress of the steel box girder at the slipway under the typical disadvantageous condition meets the requirements of the specification;(2)in the unstressed state,the transverse 4 slideways have the same elevation on the top surface and the same height at the bottom of the beam;(3)under the self weight effect of steel box girder,the counterforces of transverse 4 slideways are not equal,and the distribution ratio of the counterforce to the internal and external slideways is 1.69:1;(3)under the condition of the pad adapting the designed area,the local stress of the steel box girder at the slideway is the best when the pad’s equivalent elastic modulus reduced to 60%of the steel;(4)the stress of the main forced member of the steel box girder at the slideway is sensitive to unsynchronized jacking and rotation error of transverse 4 slideways;(5)the safety threshold of the vertical jacking height difference is±5 mm,the elevation on the top of the outer steel pad is 2 mm higher than that of the top of the inner steel pad;(6)the allowable axis deviation for the incremental launching in Technical Specification for Construction of Highway Bridge and Culverts is 10 mm,there is a certain
作者
李传习
陈卓
董创文
李涛
LI Chuan-xi;CHEN Zhuo;DONG Chuang-wen;LI Tao(School of Civil Engineering and Architecture,Changsha University of Science and Technology,Changsha Hunan 410004,China;Sichuan Road & Bridge Group Co.,Ltd.,Chengdu Sichuan 610000,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2019年第4期72-79,共8页
Journal of Highway and Transportation Research and Development
基金
国家重点基础研究计划(九七三计划)项目(2015CB057701)
国家自然科学基金项目(51778069
51378080)
广东省交通运输厅科技项目(201602010)
湖南省开放基金项目(15K010)
关键词
桥梁工程
应力分析
混合有限元法
宽幅钢箱梁
步履式顶推
材料参数
施工误差
bridge engineering
stress analysis
mixed finite element method
wide steel box girder
walking-type incremental launching
material parameter
construction error
