基于轮轨接触几何状态的地震作用下高速列车过桥安全性指标研究

In earthquake-prone regions,the probability that the running safety of high-speed train passing the bridge and subjected to the seismic ground motion decreases greatly is much higher than before. The possible separation between the rail and the wheel set may occur, which illustrates that the running safety evaluation indexes based on non-separation model don't work well. The existing research methods and results have been summarized. A complex research method including theoretical analysis, experimental verification and numerical simulation is adopted. Combined with high-speed railway bridge engineering, a coupled model consisting of foundation, bridge, track, and high-speed train is established, in which soil-structure and track-train interactions are simultaneously taken into account and the possible separation between the rail and the wheel set is simulated. An effective integration method and an analysis framework are presented to solve the equilibrium equations of motion of the coupled system. The computer program for the problem concerned is compiled. The influence of train group, train speed, track irregularity level and seismic ground motion characteristics on the coupled system is investigated. Finally, the running safety evaluation indexes of high-speed train are proposed in terms of the wheel/rail contact geometry status. The research project can not only provide the theory and technical supports to guarantee the running safety of high-speed train but also improve the bridge aseismatic theory, in which there are important engineering significance and broad prospect of application.

在地震多发地区高速列车行驶在桥梁上遭遇突发地震作用从而导致运行安全性大大降低的概率日益增加。地震发生时列车轮对与钢轨之间可能发生瞬间分离，这充分说明基于轮轨密贴模型所提出的列车运行安全性评价指标不再适用。为此申请者在总结以往研究方法和成果的基础上，结合实际高速铁路桥梁工程，采用理论分析、试验验证、数值模拟相结合的研究方法，建立地震作用下既能同时考虑土与结构、轨道与高速列车动力相互作用又能模拟轮轨可能分离现象的地基-桥梁-轨道-高速列车耦合分析模型，研制适用的高效积分方法和计算框架，编制仿真分析程序，研究列车编组、列车速度、轨道不平顺等级、地震动特性等因素对耦合系统动力响应的影响规律，最终提出基于轮轨接触几何状态的高速列车运行安全性评价指标。该课题的研究既可以为保证列车运行安全性提供理论基础与技术支撑，又可以完善桥梁抗震理论，具有重要的工程意义和广泛的应用前景。

在地震多发地区高速列车行驶在桥梁上遭遇突发地震作用从而导致运行安全性大大降低的概率日益增加。地震发生时列车轮对与钢轨之间可能发生瞬间分离，这充分说明基于轮轨密贴模型所提出的列车运行安全性评价指标不再适用。为此申请者在总结以往研究方法和成果的基础上，结合实际高速铁路桥梁工程，采用理论分析、试验验证、数值模拟相结合的研究方法， 建立了地震作用下既能同时考虑轨道与高速列车动力相互作用又能模拟轮轨可能分离现象的桥梁—轨道—高速列车耦合分析模型，研制了适用的高效积分方法和计算框架，编制了仿真分析程序，研究了列车编组、列车速度、轨道不平顺等级、地震动特性、桥址地形特征等因素对耦合系统动力响应的影响规律， 提出了基于轮轨接触几何状态的高速列车运行安全性评价指标，最终，以地震强度为横向坐标，以列车运行安全临界速度的最大值为纵坐标，绘制了地震作用下列车安全界限图。研究表明：接触点横移量和车轮抬升量能够体现轮轨接触几何状态，可以用作车辆行走安全性的参考指标，传统安全性指标可以通过引入超限时间来进行修正；局部地形对车桥系统响应的影响不可忽略。该课题的研究既可以为保证列车运行安全性提供理论基础与技术支撑， 又可以完善桥梁抗震理论， 具有重要的工程意义和广泛的应用前景。