基于元胞自动机微观模拟的随机车流与桥梁耦合振动数值研究

NUMERICAL INVESTIGATION ON RANDOM TRAFFIC-BRIDGE COUPLED VIBRATION USING CELLULAR AUTOMATONBASED MICROSCOPIC SIMULATION

将经典车桥耦合振动理论与最新提出的多轴单元胞自动机(MSCA)微观车流荷载模拟方法进行融合,形成了一种精细化的随机车流与桥梁耦合振动数值分析方法。介绍了该研究所采用的车桥耦合振动理论及模型;提出了MSCA实现车桥动力分析的思路和方法,并进行了程序开发;通过具有实测时程动态挠度的工程算例,验证MSCA实现车桥耦合动力分析的准确性;将MSCA用于随机车流激励下某斜拉桥的动力效应分析中,论证基于MSCA的随机车流与桥梁耦合振动分析程序的可靠性。研究结果表明:工程算例很好地证明了该文所提方法和模型在进行车桥耦合分析的准确性,最大误差仅为11.6%;斜拉桥在随机车流作用下的静力与动力时程挠度分析显示,两者具有很好的一致性,随着路面粗糙度等级提升两者差异更加显著,说明了该模型和方法在开展随机车流与桥梁耦合振动分析的可靠性。该研究进一步拓展了MSCA在随机车流激励下分析桥梁各类动态响应的能力,为该方法程序在实桥监测与评估的应用提供了基础。

A numerical delicacy method for random traffic-bridge coupled vibration analysis is proposed.Incorporating the classical vehicle-bridge interaction theory,it is a newly established multi-axle single-cell cellular automaton(MSCA)-based microscopic traffic load simulation approach.The utilized equations and models in the classical vehicle-bridge interaction theory are introduced.The concepts and routes of the realization of MSCA for vehicle-bridge coupled dynamic analysis are proposed,and the relevant code program is developed.An engineering example with measured time-history dynamic deflections is utilized to verify the accuracy of the vehicle-bridge interaction analysis by MSCA.MSCA is used to analyze the dynamic load effects of a cable-stayed bridge under the excitation of random traffic loads,to demonstrate the reliability of the proposed approach.The results indicate that MSCA has good accuracy in vehicle-bridge coupling analysis.The maximum error in the engineering example is 11.6%.The static and dynamic time-history deflections of the cable-stayed bridge under random traffic loads show that they have good consistency,and the difference between them becomes more significant along with the increase in the pavement roughness grade.These prove the reliability of the proposed model and method in the random traffic-bridge coupled vibration analysis.This study forwards MSCA's ability to analyze various types of dynamic load effects of bridges under the excitation of random traffic flow,which provides more applications of MSCA in monitoring and evaluation of real bridges.