基于路面时域模型的交通量与动荷载关系研究

发布时间：2018-12-30 17:04

【摘要】：目前车辆动荷载理论是路面设计、道路养护等领域的热点研究问题之一。通过车辆动荷载的研究与应用能够更加准确地描述车辆运动对于路面的荷载情况,进而提高道路损坏速度预估精度、降低道路养护成本以及提高使用年限等等。然而,在目前的路面设计规范中,荷载的计算仍然以静荷载为主,动荷载的应用仍然十分有限。因此,对于车辆动荷载的研究仍然具有非常高的实际意义和工程价值。速度作为车辆动荷载的影响因素,对动荷载的计算起着至关重要的作用。但车流区间速度数据很可能由于采集设备限制而难以准确获得,这样就很可能造成车辆动荷载的研究成果在实际应用中的不便。因此,为了解决这一问题,研究利用交通量可以理论上通过函数关系推导区间速度的特点和交通量数据更加容易精确获取的优势,采用交通量代替速度的方法,研究在城市道路下交通量对车辆动荷载的影响。研究以河北省唐山市城市交通流现状为依托,实际详细采集了主干路、次干路以及城市快速路数据。根据实测数据重新标定了格林希尔兹模型、S模型以及BPR模型。通过数据分析和对比,选取了重新标定后的BPR模型作为交通量对动荷载研究中流量与速度关系的基础模型。基于正弦波叠加法的时域模型建立了交通量与路面不平度的函数关系,并为验证成果给出了在不同条件下代表性流量的时域频谱。采用二自由度模型作为车辆简化振动模型并建立了车辆动力学方程,根据车辆振动模型的求解结果建立了交通量与动荷载之间的函数关系。最后为验证交通量与动荷载研究成果,分别利用振型叠加法和Newmark-β法进行解耦求解,并给出不同交通量条件下动荷载系数频谱。研究结果表明:交通量对车辆动荷载影响明显,在相同等级路面下,交通量越大,车流速度越低,动荷载系数越小;交通量在较低和较高的情况下动荷载变化较小,相对应的变化较大区间流量为500-1000pcu/h/lane;采用Newmark-β法和振型叠加法解耦所获得的结果均符合实际变化规律,进而证明了交通量作为参数计算车辆动荷载的有效性与可行性。
[Abstract]:At present, the theory of vehicle dynamic load is one of the hot research issues in the field of pavement design and road maintenance. Through the research and application of vehicle dynamic load, it can more accurately describe the load of vehicle movement on road surface, and then improve the accuracy of road damage speed prediction, reduce the road maintenance cost and improve the service life, and so on. However, in the current pavement design code, the calculation of loads is still mainly static load, and the application of dynamic load is still very limited. Therefore, the study of vehicle dynamic load still has high practical significance and engineering value. As the influence factor of vehicle dynamic load, velocity plays an important role in the calculation of dynamic load. However, the velocity data of vehicle flow section may be difficult to obtain precisely due to the limitation of acquisition equipment, which may cause inconvenience in the practical application of the research results of vehicle dynamic load. Therefore, in order to solve this problem, the paper studies the advantages of using traffic volume to deduce the characteristics of interval speed through function relation and the advantage that traffic volume data can be obtained more easily and accurately, and adopts the method of traffic volume instead of speed. The effect of traffic volume on vehicle dynamic load on urban roads is studied. Based on the present situation of urban traffic flow in Tangshan City, Hebei Province, the data of main road, secondary trunk road and urban expressway are collected in detail. Based on the measured data, Green Shields model, S model and BPR model are re-calibrated. Based on the data analysis and comparison, the recalibrated BPR model is selected as the basic model of the relationship between flow and velocity in the study of traffic volume to dynamic load. Based on the time domain model of sinusoidal superposition method, the relationship between the traffic volume and the road roughness is established, and the time domain spectrum of the representative flow under different conditions is given to verify the results. The two-degree-of-freedom model is used as the simplified vibration model of the vehicle and the vehicle dynamics equation is established. The functional relationship between the traffic volume and the dynamic load is established according to the solution results of the vehicle vibration model. Finally, in order to verify the research results of traffic volume and dynamic load, the vibration mode superposition method and Newmark- 尾 method are used for decoupling solution, and the spectrum of dynamic load coefficient under different traffic volume is given. The results show that the influence of traffic volume on vehicle dynamic load is obvious. The larger the traffic volume is, the lower the speed of vehicle flow is and the smaller the dynamic load coefficient is. Under the condition of lower and higher traffic volume, the change of dynamic load is relatively small, and the corresponding larger range flow rate is 500-1000pcur / h / lane. The results obtained by decoupling the Newmark- 尾 method and the mode superposition method are in accordance with the actual variation law, which proves the validity and feasibility of calculating the vehicle dynamic load by using the traffic volume as a parameter.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.2

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