基于可靠性理论的钢弹簧浮置板过渡段评价指标研究

Study on Evaluation Index of Transition Section of Steel Spring Floating Slab Based on Reliability Theory

实现地铁整体道床到钢弹簧浮置板轨道的有效过渡是延长轨道结构服役寿命和保证列车运行安全的核心问题。本文基于车辆-轨道耦合动力学理论,通过建比钢弹簧浮置板过渡段的数值计算模型,引入钢轨垂向挠度变化率作为评价钢弹簧浮置板过渡段动力学影响指标,采用基于结构可靠度理论的响应面方法进行计算,讨论扣件、正常钢弹簧和加密钢弹簧三种轨道结构随机参数下结构服役的可靠性。结果表明,钢弹簧浮置板过渡段钢轨垂向挠度变化率控制指标限值为1.17 mm/m;钢弹簧浮置板轨道刚度与钢轨垂向挠度变化率具有负相关性。建议将钢轨垂向挠度变化率作为过渡段关键性指标控制限值。

The effective transition from subway monolithic track bed to steel spring floating slab track is the core issue to prolong the service life of track structure and ensure the safety of train operation.Based on the vehicle-track coupling dynamics theory,the numerical calculation model of steel spring floating slab transition section is established,and the rail vertical deflection change rate is introduced as the dynamic influence index for evaluating the transition section of steel spring floating slab.The response surface method based on structural reliability theory is used to calculate,and the structural service reliability under the random parameters of fastener,normal steel spring and dense steel spring is discussed.The results show that the control index limit of the change rate of rail vertical deflection in the transition section of steel spring floating slab is 1.17 mm/m;the stiffness of steel spring floating slab track is negatively correlated with the change rate of rail vertical deflection.It is suggested that the change rate of rail vertical deflection should be taken as the key index control limit in the transition section.