Investigation of seismicperformance of viaducts considering traffic loadings and safety of moving whieles

本研究旨在研究公路桥梁、新干线高架桥和单轨铁路桥梁在交通荷载作用下的地震反应，其中考虑桥梁-车辆/列车相互作用的情况下发生中等地震的概率很大。还对公路桥梁和新干线列车上的车辆在地震中的运行稳定性进行了检验。为了实现本研究的目的，将新干线和单轨列车的自卸车和车辆分别理想化为12个自由度和15个自由度的离散刚体多体系统。这些车辆和列车模型包括地震时与横向有关的运动，如摇摆和偏航运动。通过数值分析的观察表明，重型车辆和列车的存在也是动力系统，可以影响桥梁的地震反应：车辆和列车的动力系统起到…的作用地震时更像是桥梁上的阻尼器。这一事实尤其表明，包括单轨桥梁在内的现有铁路设计将列车视为额外质量，产生了一个保守的结果。还观察到，与静止车辆相比，高速公路桥梁上行驶的车辆可能会更频繁地经历打滑。此外，在地震期间，高架桥上的车辆比公路上的车辆更容易打滑。利用脱轨系数对新干线列车进行脱轨评估，结果表明脱轨系数随列车运行速度的增加而增大。对单轨列车地震反应的研究表明，先进桥梁的地震反应比传统单轨桥梁大，这是由于先进桥梁的组合梁简化了结构体系，增加了主梁的重量。此外，先进桥梁上的列车比常规桥梁上的列车具有更大的动力响应。较少

This study is intended to investigate the seismic response of highway bridges, Shinkansen viaducts and monorail bridges under traffic loads using three-dimensional dynamic response analysis, which even considers bridge-vehicle/train interaction subjected to moderate earthquakes occurring with high probability. The running stability of vehicles on highway bridges and Shinkansen train during earthquakes is also examined. To realize the purpose of this study, a dump truck and the car of train of Shinkansen and Monorail are respectively idealized as a discrete rigid multi-body system with 12 degrees of freedom (DOFs) and 15DOFs. Those vehicle and train models comprise the motions relating to the lateral direction, such as sway and yawing motions, during earthquakes.Observations through a numerical analysis demonstrate that the existence of heavy vehicles and trains, which are also dynamic system, can affect the seismic response of bridges: the dynamic system of vehicles and trains acts as … More a damper on the bridges during earthquakes. That fact especially shows that the existing railway design including monorail bridges, which considers a train as additional mass, yields a conservative result. It is also observed that moving vehicles on highway bridges may experience the slip more frequently in comparison with stationary vehicles. Moreover, during earthquakes vehicles on viaducts becomes easy to slip comparing with those on roadways. The derailment assessment of Shinalkansen train using the derailment coefficient clarifies that the derailment coefficient increases with increasing train speeds. Investigations for the seismic response of monorail trains reveal that the seismic responses of the advanced bridges are greater than those of the conventional monorail bridges because of the simplified structural system and increased girder weight that is attributable to composite girders of the advanced bridges. Moreover, the train on the advanced bridge shows greater dynamic response than that on the conventional bridge. Less