轨道结构建模精细化程度对高速铁路连续梁桥地震易损性的影响

为探究CRTS Ⅱ板式无砟轨道结构建模精细化程度对高速铁路连续梁桥地震易损性曲线的影响，以一座48 m+80 m+48 m高速铁路预应力混凝土连续梁桥为例，采用有限元分析软件OpenSEES分别建立四个轨道结构建模精细化程度不同的线桥一体化模型，进行了非线性时程分析和易损性分析，构造了桥梁各关键构件和轨道结构各部件的易损性曲线。计算结果表明，在建立轨道-桥梁一体化模型研究高铁连续梁桥抗震性能时，轨道结构建模精细化程度对滑动层的地震易损性曲线影响很大。随着轨道结构建模的精细化程度降低，滑动层发生地震破坏的概率变大。同时，轨道结构建模越简单，滑动支座发生破坏的概率略微增加，桥墩发生破坏的概率略微减小。此外，轨道结构建模的精细化程度对CA层、扣件、桩基等构件的地震易损性曲线基本上没有影响。

THE EFFECTS OF MODEL REFINEMENT OF BALLASTLESS TRACKS ON THE SEISMIC VULNERABILITY OF A CONTINUOUS BRIDGE ON A HIGH-SPEED RAILWAY

By taking a high-speed railway prestressed concrete continuous girder bridge with spans of 48 m+80 m+48 m as an example, the effects of the model refinement of ballastless tracks on the seismic vulnerability were analyzed. The software OpenSEES is used to build four track-bridge models with different model refinement levels of the ballastless tracks. A large number of vulnerability curves of the bridge and track components were obtained. The results show that the seismic vulnerability curves of the sliding layer are greatly influenced by the model refinement of track structure. As the model refinement of track structures is reduced, the failure probability of the sliding layer increases, while it has less influence on the vulnerability curves of the sliding bearing and the pier. Similarly, the sliding bearings are a little more vulnerable with the less refined ballastless track model. On the contrary, the piers are a little less vulnerable. In addition, the model refinement of track structures has feeble influence on the seismic vulnerability curves of the CA layer, fasteners, piles and other components.