基于震后轨道残余变形的桥梁-纵连板式无砟轨道系统性能评估研究

The bridge and longitudinally-connected slab track structure system is widely used in Chinese high-speed railway. However, its track residual deformation caused by earthquake poses a serious threat to train traffic safety. The bridge and longitudinally-connected slab track system with vertical multilayer structure characteristics is taken as the research object by this topic so as to improve the system performance evaluation method considering the influence of track post-earthquake residual deformation on train operation safety, and its specific content includes: based on the dynamic hysteretic performance of key components such as fastener and sliding layer obtained by model test, the 3D fine seismic simulation model of bridge and longitudinally-connected slab track system is set up, fully considering both material and nonlinear constraints between layers; after ascertaining the residual deformation law and mode of the post-earthquake track structure, the post-earthquake track residual deformation evaluation method is studied based on traffic safety; taking track residual deformation after earthquake as one of system damage criteria, performance evaluation method of both bridge and longitudinally-connected slab track system is improved, considering the post-earthquake traffic safety. Research results of the topic can further enrich the continuously welded rail unballasted track design theory on bridge, which can provide not only a scientific basis for the design, maintenance and reinforcement of bridge and track structure in seismic region, but also an important reference for setting anti-seismic performance evaluation standard of railway bridges.

我国高速铁路广泛采用桥梁-纵连板式无砟轨道结构体系，地震作用下其震后轨道残余变形将严重威胁列车运行安全。本课题以具有竖向多层构造特点的桥梁-纵连板式无砟轨道系统为研究对象，发展考虑轨道震后残余变形对列车运行安全影响的系统性能评估方法，研究内容包括：基于模型试验研究扣件和滑动层等关键构件动力滞回性能，建立充分考虑材料和层间非线性约束的桥梁-纵连板式无砟轨道系统三维精细化地震仿真模型；在探明震后轨道结构残余变形规律及模式的基础上，研究基于行车安全的震后轨道残余变形评价方法；将震后轨道残余变形作为系统损伤指标之一，发展考虑震后行车安全的桥梁-纵连板式无砟轨道系统性能评价方法。通过本课题的研究，将进一步丰富桥上无砟轨道无缝线路设计理论，为震区桥梁及轨道结构的设计、维修和加固提供科学依据，为铁路桥梁抗震性能评估标准的制定提供重要参考。

我国高速铁路广泛采用桥梁-纵连板式无砟轨道结构体系，实际铺设里程已超过9000km（单线）。与非纵连无砟轨道不同，桥上纵连板式无砟轨道采用以承受轴向荷载为主的连续钢筋混凝土底座板结构、并使用滑动层与桥梁结构进行有效隔离，实现了长达跨度桥上无砟轨道的连续铺设。桥梁-纵连板式无砟轨道具有纵向多变、竖向多层的构造特点。地震作用下，桥梁-纵连板式无砟轨道系统动力响应规律较为特殊，其变形作用对行车安全的影响仍不明确。本课题以桥梁-纵连板式无砟轨道系统为研究对象，研究桥上纵连板式无砟轨道系统地震响应机制：建立了充分考虑材料和层间非线性约束的桥梁-纵连板式无砟轨道系统三维精细化动力仿真模型，该模型分析精度可满足工程需要；揭示了桥梁-纵连板式无砟轨道系统地震响应规律，与CRTSⅠ型无砟轨道结构相对比，提出了地震作用下纵连板式无砟轨道系统受力和变形特征，探讨了轨道变形对行车安全的影响；分析了震时扣件、滑动层等关键构件的滞回耗能特性；研究了轨道板宽接缝、底座板开裂以及砂浆层离缝等轨道结构损伤对桥梁-纵连板式无砟轨道系统地震响应的影响规律，探讨了典型轨道结构损伤对行车安全的影响机制；分析了列车及日温度变化荷载耦合作用下大跨度斜拉桥上无砟轨道的疲劳特性。通过本课题的研究，丰富了桥上无砟轨道无缝线路设计理论，为震区桥梁及轨道结构的设计、维修和加固提供科学依据。项目执行期间，在国内外知名期刊发表论文8篇，其中SCI检索3篇、EI检索4篇；授权发明专利3项、软件著作权2项；翻译出版行业标准2部。培养博士生2人、硕士生6人（含外籍硕士生1人），举办中泰、中日小型学术会议各1次，支持学生参加国际学术会议并做汇报8人次。