摘要
为实现刹车时桥上多状态车流并行动态演化的高真实度模拟和时变汽车荷载与桥梁运动状态的时时耦合,首先从宏观和微观上丰富随机车流模拟方法,宏观上沿用交通荷载调查数据中的车辆顺序、车辆基本特性等不变量,以车辆间距为服从正态分布的限幅随机变量,形成深度融合交通荷载调查数据和交通流理论的随机车流高真实度仿真方法;微观上对车辆间距随机变量确定的关键状态-阻塞状态,引入加权速度,实现阻塞密度时车流的走走停停动态描述,采用考虑驾驶人状态的概率分布方法确定车辆时距;实现多密度随机车流的高真实度仿真。其次细化刹车过程模拟,建立车流差异化刹车模型:采用顺次对比方法,筛选桥长范围最不利刹车车流;引入停车视距,考虑驾驶人反应,区分头车和跟驰车辆,精细模拟车辆刹车动态过程和刹车车流演化过程,差异化确定各车辆刹车参数;实现桥上多状态车流并行动态演化模拟。第三建立刹车力学模型,并融入至已有正常车流的车-桥耦合系统,构建可考虑刹车状态的分析系统。最后确定桥梁典型响应和分析指标,以一座大跨斜拉桥为例,对多刹车工况下的桥梁响应进行分析。结果表明:桥上刹车状况一般会产生超过正常行驶状况下的桥梁响应,最不利单车道刹车状况下的塔根弯矩甚至达到跑车工况的2.7倍,简单采用规范冲击系数方法很难实现刹车响应的包络;刹车过程中的桥梁响应最值不仅与采取刹车的车辆数目和桥上车辆保有量有关,还受刹车作用与桥梁原响应趋势的顺逆程度控制;桥梁及桥上刹停车辆的总质量和桥上正常行驶的车辆决定桥梁响应时程曲线趋势振幅;典型桥梁响应的总体趋势,与车流密度和刹车车道数相关性较小,不同时段车流会对梁端顺桥向位移和塔根弯矩产生影响。
To realize high-fidelity simulation of the parallel dynamic evolution of multistate vehicle flow on a bridge and the time-time coupling of time-varying vehicle load and bridge motion state during braking,random traffic flow simulation methods were first enriched from macro and micro perspectives.The invariants of vehicle sequence and basic characteristics of traffic load survey data were used at the macro-level.Vehicle spacing was considered a limiting random variable subject to normal distribution,and a high-fidelity simulation method of stochastic traffic flow based on deep fusion of traffic load survey data and traffic flow theory was developed.The critical blocking was used to determine the random variables of vehicle spacing microscopically,the weighted speed was introduced to realize the dynamic description of the stop-and-go of traffic flow under jam density.Vehicle time interval was determined using the probability distribution method considering driver’s state,and high-fidelity simulation of multi density random traffic flow was realized.Secondly,the braking process simulation was refined and the differential braking model was established.Using the sequential comparison method,the most unfavorable brake flow in the bridge length range was screened.By introducing the parking sight distance,considering the driver’s reaction,differentiating the head vehicle from the following vehicle,simulating of vehicle dynamic braking process,and the brake flow evolution process,the braking parameters of each vehicle can be determined by differentiation;the simulation of parallel dynamic evolution of multistate vehicle flow on bridge was realized.Thirdly,the brake mechanics model was established and integrated into the existing normal vehicle flow-bridge coupling system to build an analysis system that can consider the brake state.Finally,the typical response and analysis index of the bridge was determined by taking a long-span cable-stayed bridge as an example,and the response of the bridge under multi braking condi
作者
刘焕举
韩万水
刘宁
高颖
韩晓斌
LIU Huan-ju;HAN Wan-shuiz;LIU Ning;GAO Ying;HAN Xiao-bin(School of Civil Engineering,Hebei University of Engineering,Handan 056038,Hebei,China;School of Highway,Chang’an University,Xi’an 710064,Shaanxi,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2020年第4期76-88,共13页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51908178.51878058)
河北工程大学创新基金项目(SJ010002157)
中央高校基本科研业务费专项资金项目(310821171002)。
关键词
桥梁工程
随机车流动态演化
数值模拟
刹车
车-桥耦合
bridge engineering
dynamic evolution of stochastic vehicle flow
numerical simulation
braking
vehicle-bridge coupling
