行驶中的车辆荷载波动及其对沥青路面结构设计的影响

发布时间：2018-04-04 02:20

本文选题：仿真路面　切入点：车辆荷载　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：目前设计寿命为15年的高速公路沥青路面,往往在通车后2~3年内就出现了不同程度的早期破坏现象。出现该困境的原因是车辆行驶于不平整的路面上,受路面激励的影响会产生随机振动,使部分路面受力增大,导致路面平整度下降,而路面平整度恶化又会加剧车辆振动,使路面受到更大的作用力,行驶中的车辆荷载与平整度之间的关系,大大加速了路面破坏。而我国现行沥青路面结构设计中各车型轴载为静态荷载,实际作用于路面上的车辆荷载具有一定的空间重复性和数值波动性。设计与实际的偏差使设计的路面无法达到使用年限。从仿真路面高程入手,应用滤波白噪声法仿真出各个路面功率谱密度下的路面高程,并考虑路形影响,建立路面功率谱密度与国际平整度指数之间的关系。据此,仿真出各个平整度下的路面高程,经验证仿真路面高程正确有效。将仿真路面高程作为考虑装载影响的双轴货车半车动力学模型的输入,选取适当的仿真路面长度和个数,计算得到各个平整度、车速和轴载下的路面各点行驶中的车辆荷载,并对比分析了双轴货车半车系统模态和行驶中的车辆荷载幅频特性。对不同平整度、车速和轴载作用下的车辆荷载波动规律进行了分析,得到了车辆以不同车速和轴载行驶于同一路面时,行驶中的车辆荷载在路面同一位置具有空间可重复性的结论。还以行驶中的车辆荷载标准差作为代表值,得到了行驶中的车辆荷载各影响因素的规律和敏感性,其中平整度为首要影响因素,并确定了其分布特性和分布概率。结合实例分析行驶中的车辆荷载对沥青路面结构设计的影响,具体包括对路面使用寿命、设计弯沉值、各层层底拉应力和沥青路面平整度养护标准的影响。
[Abstract]:At present, asphalt pavement with a design life of 15 years often appears early damage phenomenon in different degree within 2 ~ 3 years after opening to traffic.The reason for this predicament is that the vehicles driving on uneven road surface will produce random vibration under the influence of the road surface excitation, which will increase the force on part of the road surface and cause the road surface smoothness to decrease, and the deterioration of the road surface smoothness will aggravate the vehicle vibration.The relationship between vehicle load and smoothness greatly accelerates the pavement damage.However, in the design of asphalt pavement structure in China, the axle load of each vehicle model is static load, and the vehicle load acting on the pavement has a certain spatial repeatability and numerical fluctuation.The deviation between design and practice makes the designed pavement unable to reach the service life.Based on the simulation of road height, the white noise filtering method is used to simulate the road height under the power spectral density of road surface, and the relationship between the power spectral density of road surface and the international smoothness index is established considering the influence of road shape.According to this, the pavement elevation under various smoothness is simulated, and it is proved that the simulated pavement elevation is correct and effective.Taking the simulated road height as the input of the dynamic model of the two-axle freight car considering the loading effect, selecting the appropriate simulation road surface length and number, the vehicle load at each point under the load, the speed and the vehicle load are calculated.The mode of half-vehicle system and the amplitude-frequency characteristics of vehicle load are compared and analyzed.The fluctuation law of vehicle load under the action of different smoothness, speed and axle load is analyzed, and the vehicle driving on the same road with different speed and axle load is obtained.The conclusion that the vehicle load in progress has spatial repeatability in the same position of road surface.Taking the vehicle load standard deviation as the representative value, the law and sensitivity of the factors affecting the vehicle load are obtained, in which the flatness is the primary factor, and the distribution characteristics and distribution probability are determined.The influence of vehicle load on asphalt pavement structure design is analyzed with examples, including the influence of pavement service life, design deflection value, layer bottom tensile stress and asphalt pavement smoothness maintenance standard.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.217

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