摘要
为防止节段预制箱梁胶接缝边缘出现斜裂缝而引起的破坏,采用数值分析和拉压杆模型的方法开展研究,揭示此类斜裂缝的开裂机理,提出节段预制箱梁接缝边缘竖向配筋以及腹板中部水平配筋的计算方法。基于笔者以及Turmo等所做的试验建立节段预制箱梁纯弯段标准节段有限元模型,进行详细数值模拟分析,得到节段预制箱梁的应力场分布;以应变能最小为优化目标,对节段预制箱梁纯弯段进行拓扑优化分析,明确荷载传递路径。根据以上弹性应力分析和拓扑优化分析结果,建立节段预制箱梁纯弯段标准节段的拉压杆模型并进行验证,定量确定节段预制箱梁边缘的竖向拉力和腹板中部水平拉力的大小,提出节段预制箱梁胶接缝边缘竖向配筋以及腹板水平配筋的计算方法和公式。最后以南京长江四桥引桥标准节段箱梁为例,利用推荐的节段预制箱梁纯弯段标准节段拉压杆模型,对节段箱梁胶接缝边缘竖向配筋及腹板水平配筋进行校核,并给出相应的配筋建议。研究结果表明:利用提出的节段预制箱梁纯弯段标准节段拉压杆模型进行节段箱梁胶接缝边缘竖向配筋以及腹板水平配筋,设计更加合理且具有理论依据,进而验证了节段箱梁接缝边缘配筋计算方法的可行性。
In order to prevent the damage caused by diagonal crack near the edge of joints in segmental precast box girder,and study the cracking mechanism for a diagonal crack by means of numerical simulation analysis and strut and tie model method,a calculation method which could determine the requirement of vertical reinforcement at the edge of epoxy joint and horizontal reinforcement at the middle of the web was proposed.Based on the experimental phenomena observed during author＇s and Turmo＇s tests,a finite element model for standard segments of precast segmental box girders under pure bending was established,the numerical simulation was carried out in details,and the stress field distribution for a selected segmental box girders was obtained.In order to minimize strain energy as optimization objective,the technique usingtopological optimization was adopted to explicit the load path of the standard segments of precast segmental box girder under pure bending.Based on the results of the elastic stress analysis and topological optimization analysis mentioned above,a strut-and-tie model for the standard segments of precast segmental box girder under pure bending was established and verified,through which the magnitude of vertical tension force and horizontal web tension force were quantitatively determined,and the calculation methods and formulas were provided for determining the reinforcement requirement at edge of epoxy joints and at the middle of web of the segments.Finally,the research took a segment of the precast segmental box girder from the Fourth Nanjing Yangtze River Bridge as an example utilized strut-and-tie model which recommended previously fir the standard segment was adopted to check the requirement of vertical reinforcement at edge of the joint and horizontal reinforcement in the web,some corresponding recommendations for reinforcement design was provided.The results show that using the strut-and-tie model for the standard segment to design the reinforcement requirement at the edge of joints and at the middle of web is more reasonable and have the theoretical basis,which further verifies the feasibility of the calculation methods.8 figs,24 refs.
作者
袁爱民
陆荣伟
徐冬辉
YUAN Ai-min;LU Rong-wei;XU Dong-hui(College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, Jiangsu, China)
出处
《长安大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第2期62-68,共7页
Journal of Chang’an University(Natural Science Edition)
基金
江苏省交通科学研究计划项目(2013Y11)
关键词
桥梁工程
节段预制箱梁
胶接缝
拓扑优化
拉压杆模型
配筋设计
bridge engineering
precast segmental box girder
epoxy joint
topology optimization
strut-and-tie model （STM）
reinforcement design
