基于拓扑优化和缩尺试验的小宽厚比独柱式桥墩帽梁力学性能研究  

Mechanical Property Study on Cap Beam of Single-column Pier with Small Width-thickness Ratio Based on Topology Optimization and Scale-down Test

作　　者：胡赛鸿 常柱刚 邓海波 丁磊 HU Sai-hong;CHANG Zhu-gang;DENG Hai-bo;DING Lei(Changsha Urban Construction Investment and Development Group Co.,Ltd.,Changsha,Hunan 410007,China;Changsha Planning&Design Institute Co.,Ltd.,Changsha,Hunan 410007,China)

机构地区：[1]长沙市城市建设投资开发集团有限公司,湖南长沙410007 [2]长沙市规划设计院有限责任公司,湖南长沙410007

出　　处：《公路交通科技》2024年第5期97-107,共11页Journal of Highway and Transportation Research and Development

摘　　要：由于小宽厚比独柱墩帽梁属于典型的应力扰动区构件,内部受力较为复杂,普通独柱墩帽梁的设计方法可能对其不适用。对小宽厚比独柱墩帽梁模型进行拓扑优化,分析小宽厚比独柱墩帽梁的空间受力特征,根据拓扑优化结果建立小宽厚比独柱墩帽梁的空间拉压杆模型基本构形,并根据最小应变能准则提出了确定其最优构型的方法。针对目前对小宽厚比独柱墩帽梁试验研究较少的现状,进行缩尺模型试验,研究其竖向静载作用下的受力特性。结果表明:在横桥向,帽梁顶部在双支座荷载下具有最大拉应力;在顺桥向,帽梁中间位置拉应力最大,帽梁的顶部拉应力低于中部,帽梁底部则表现出受压的趋势。由于未考虑顺桥向的力流扩散,根据相关规范中拉压杆模型设计方法计算得到的内力值与试验结果相差较大,说明规范法不适用于小宽厚比独柱墩帽梁的设计。试验结果的应力分布情况与根据拓扑优化结果提出的空间拉压杆模型一致,并且采用空间拉压杆模型计算得到的拉杆应力值相比规范法更加合理,证明本研究所提的空间拉压杆模型基本构形以及确定最优构型方法的合理性。Since the cap beam of single-column pier with small width-thickness ratio belongs to the typical stress disturbance zone members,its complicated internal forces make it unapplicable to the design method for ordinary cap beam of single-column pier.The topology optimization was performed on the model of cap beam of single-column pier with small width-thickness ratio,and its spatial force characteristics were analyzed.The basic configuration of spatial strut-and-tie model of cap beam of single-column pier with small width-thickness ratio was established based on the topology optimization results.The method for determining optimal configuration was proposed according to the minimum strain energy criterion.In view of limited experimental studies on cap beam of single-column pier with small width-thickness ratio,a scale-down model test was conducted to investigate the force characteristics under vertical static loading.The result indicates that in the transverse direction,the top of cap beam has the maximum tension stress under double support loads.In the longitudinal direction,the middle of cap beam has the maximum tension stress,the top of cap beam has lower tension stress than the middle of cap beam,and the bottom of cap beam shows a tendency of being subjected to compression.Since the force diffusion in longitudinal direction is not considered,the internal forces calculated according to strut-and-tie model design method in the relevant specification differed greatly from test result,indicating that the method in specification is not applicable to the design of cap beam of single-column pier with small width-thickness ratio.The stress distribution of test result is consistent with that of spatial strut-and-tie model proposed based on topology optimization result.The stress values of strutand-tie calculated with spatial strut-and-tie model are more reasonable compared with those obtained with the method in specification.It proves the reasonableness of basic configuration of spatial strut-and-tie model and the method

关 键 词：桥梁工程 小宽厚比独柱墩帽梁 空间拉压杆模型 拓扑优化 缩尺模型试验 

分 类 号：U442.5[建筑科学—桥梁与隧道工程]