强震作用下高速铁路桥梁碰撞机理、碰撞全过程及防碰控制研究

A lot of earthquake disasters indicate that bridge collision induced by strong earthquake is the main factor which brings about bridge damage. The huge impact force may lead to bearings failure, piers destruction, and even bridges collapse. High-speed railway bridge is the lifeline engineering in traffic and transportation system, and the high proportion of it in total route greatly raise the probability that the train is still running on the bridge when earthquake occurs. Also the bridge deck of the high-speed railway bridge is different to that of highway bridge and ordinary-type railway bridge. In view of these, the collision process and the collision effect of the high-speed railway bridge excited by earthquake have its own characteristics. Therefore, it is very necessary to study the collision mechanism, collision process and anti-collision control induced by earthquake for high-speed railway bridge. The project focuses on two aspects. On the one hand, based on the non-linear collision theory, the refined FEM model simulating the collision between the adjacent high-speed railway bridges is established; then the collision effect and the collision regularity subjected to strong earthquake are investigated; lastly the real-time full collision process is simulated and the collision mechanism is discovered. On the other hand, by theoretical analysis and experimental investigation, the effective measures preventing bridge collision and reducing seismic response suitably for the high-speed railway bridge in China can be found, so that bridge collapse can be prevented and the collision effect can be mitigated excited by strong earthquake. The research achievements of the project can provide strong theory support for reasonable anti-collision and earthquake resistant design for high-speed railway bridge. This research will fill the gap in the field, and produce significant value in academic and engineering application, with remarkable socio-economical benefit.

大量震害现象表明，强震引起的碰撞是引发桥梁震害的主要原因，巨大的碰撞力会导致支座失效或桥墩受损，甚至落梁。高速铁路桥梁是交通运输系统中的生命线工程，在线路中所占比重高，大大增加了地震发生时列车仍在桥上运行的概率，且桥面系构造不同于公路和普通铁路桥梁，这使得地震作用下高铁桥梁的碰撞过程及碰撞效应具有自身的特点，因此有必要开展强震作用下的高速铁路桥梁碰撞机理、碰撞全过程及防碰控制研究。本项目旨在基于非线性碰撞理论，建立高铁桥梁碰撞精细有限元模型，研究强震作用下的碰撞效应，实时模拟高铁桥梁碰撞全过程，揭示碰撞机理；通过理论分析和试验研究，寻求适合于我国高铁桥梁的有效防碰减震措施和方法，提出合理设计参数，避免强震作用下发生落梁现象，减轻结构碰撞效应。项目研究可为高铁桥梁合理防碰抗震设计提供充足理论依据，填补该领域研究空白，达到预防或减轻震害目的，具有重要的学术和工程实际价值，社会经济效益显著。

高速铁路桥梁是交通运输系统中的生命线工程，其多采用的无砟轨道桥面系（CRTSⅡ型）具有纵联特点，对桥梁结构具有较强的约束作用，这一点与公路桥梁和普通铁路桥梁具有较大的不同，这使得地震作用下高铁桥梁的碰撞过程及碰撞效应具有自身的特点，因此有必要开展强震作用下的高速铁路桥梁碰撞机理、碰撞全过程及防碰控制研究。项目研究主要内容和成果如下：.首先，基于Kelvin模型，将CRTSⅡ型轨道板的摩擦作用考虑到邻梁碰撞的运动方程中，推导出了一种适用于高铁简支梁桥的碰撞单元模型。该模型既能考虑碰撞中的能量损失，又能考虑轨道系统的摩擦作用，可简化模型建立和提高计算效率。.其次，基于ANSYS软件，建立了高速铁路（4×32m）简支梁桥的“梁-板-板-梁”和（2×32m简支梁+48+80+48m连续梁+2×32m简支梁）“叠合梁”纵向碰撞有限元模型，开展了高铁简支梁桥和连续梁桥的纵向地震响应分析，结果表明：纵联轨道系统明显增大了桥梁纵向刚度，对桥梁结构纵向地震响应影响显著；轨道系统参数对纵向地震响应影响较小，桥墩高度、桥墩刚度、桩基刚度以及邻梁间距是影响纵向地震响应的主要参数；邻梁和梁台间的限位索可有效减小梁体位移，避免邻梁碰撞，降低落梁几率。.最后，基于ABAQUS、SAP2000和ANSYS软件，分别建立了高铁桥梁横向地震碰撞的5×32m简支梁实体有限元模型、7×32m简支梁杆系有限元模型以及（2×32m简支梁+48+80+48m连续梁+2×32m简支梁）杆系有限元模型，开展了高铁简支梁桥和连续梁桥的横向地震响应分析，结果表明：轨道系统的约束作用会改变桥梁结构的动力特性与地震反应；挡块横向限位效果明显；验证了高铁简支梁桥挡块-垫石间距取值的合理性并进行了优化；各种减隔震装置能有效降低其横向碰撞效应；碰撞振动台试验直观再现了地震碰撞过程，验证了挡块的防碰效果和仿真的正确性。.本项目探究了高铁桥梁地震碰撞机理，提出了邻梁间距和横向挡块间距的合理设计参数，研究成果可达到预防或减轻震害目的，具有重要的学术和工程实际价值。