【作者】 于清；

【导师】 梁乃兴；

【作者基本信息】 重庆交通学院 ， 道路与铁道工程， 2004， 硕士

【摘要】 高等级公路的路面平整度在自然因素及行车荷载的作用下,特别是在行车动荷载的作用下将出现衰减,即路面子整度由较好的水平向较差的水平发展,也即是路面平整度变差。汽车行驶在不平整的路面上,车轮将对路面产生附加的动荷载,这种动荷载将加速路面平整度的衰减,而路面平整度的变差又将使得车轮对路面产生的附加动荷载增加。因此路面不平整度与汽车动荷载之间存在耦合作用。本论文根据西宝高速公路路面平整度的实测结果,建立了路面的不平整模型,以正弦曲线模拟路面表面;以中型载重货车为例,建立了四自由度的车辆振动模型。以上述模型为基础分析了在不同路面模型(波长、振幅不同)上车辆以不同速度行驶,左右车轮所受到的激励不同时的车辆动荷载。分析了不同条件下车辆动荷载沿路线纵向的分布。发现在波长给定时,动荷载与振幅成正比,在路面波长接近车辆自振频率下的波长时,最大动荷找迅速增加。左右车轮激励不同步在一般波长情况下使动荷载系数增大,但左右车轮激励同步将在路面的激励角频率等于车辆系统的固有角频率时使得共振作用的影响更明显,在共振时会产生更大的动荷载。本研究的分析结果指出,在路面上行驶的车辆对路面可能产生很大的动荷载。最大动荷载系数可达到2以上,表明最大动荷载是车辆静载的2倍以上,此时路面所承受的最大压力是轮胎静压力的3倍。这与长期以来人们所接受的动荷载足静荷载的0.3～0.4倍(即路面所承受的最大压力是轮胎静压力的1.3～1.4倍)的概念有较大的差别。本文按照壳牌永久变形预估理论计算了在动荷载作用下路面的永久变形,从而分析了西宝高速公路K63—K72路面的平整度变化,并与实测结果进行了对比。分析结果指出,本文的分析结果与路段的实测结果有较好的一致性,说明本文对动荷载的分析及路面平整度的变化计算是较为可靠的。本论文首次以考虑汽车侧倾因素的4自由度车辆振动模型分析行驶车辆的动荷载,使得分析精度大为提高。首次建立了路面平整度、动荷载与路面平整度变化之间的相关关系,并对路面子整度的变化做出了较为满意预测。研究成果对分析及掌握路面平整度的发展变化规律、进而为路面养护管理标准的合理制定及养护管理措施的及时实施提供了一定的理论基础,并对沥青路面使用性能的评价及沥青路面的维修养护提供技术支持,有较重要的理论价值及一定实用意义。更多还原

【Abstract】 Under natural factors and vehicle loading, especially vehicles loadings, high-level highway pavement evenness will attenuate, i.e., pavement evenness will develop to a worse condition from a better condition, also i.e. pavement evenness become worse. As vehicle moves on roughness pavement, wheel will produce additional dynamic load to pavement, which will speed up deterioration of pavement evenness, and the deterioration will make wheel increase the additional dynamic load to pavement. Therefore, there is a couple function between pavement evenness and vehicle dynamic load.According to the actual measurement result of Xi—Bao highway pavement evenness, this project sets a unevenness model of pavement which imitate pavement surface by using sine curve, and sets a vehicle vibration model of four-degree of freedom by taking the medium-sized load truck as an example. On the base of above-mentioned models, the project analyzes left wheel and right one when vehicle wheels are not impelled at the same time suffered vehicle dynamic load when vehicles travel in a different speed on the different pavement model (wave length, amplitude are different); analyzes vehicle dynamic load’s distribution along longitudinal route under different conditions. Discovering that dynamic load is in direct proportion to amplitude when wavelength is regular, the maximum dynamic load rapidly increases when pavement wavelength is close to the wavelength of vehicle automatic vibrating frequency. That left wheel and right one impelled not in the synchronism makes dynamic load coefficient increase under the common wave length condition but in the synchronism makes influence of resonance function more obvious when impelling angel frequency of pavement is equal to definite angel frequency of vehicle, producing greater dynamic load on the resonance. The analysis result of this research point out that vehicle traveling on the pavement produces probably very great dynamic load to the pavement. That maximum dynamic load coefficient may be over 2 shows maximum dynamic load is over 2 times to the vehicle dead load, at the same time maximum pressure which pavement is beard is 3 times to dead pressure of tyre. This has a big difference from the conception people accepted in a long time that dynamic load is 0.3 to 0.4 times to dead load (i.e. maximum pressure pavement beard is 1.3 to 1.4 times to dead pressure of tyre.) Based on the shell permanent deformation pre-appraisal theory, this paper calculates pavement’s permanent deformation under the dynamic load, then analyzes the evenness variation of Xi—Bao highway K63-K72 pavement, and makes a contrast to the actual measure result. The analysis result points out, that the paper’s analysis result has a fairly good consistent with the actual measure result, and show the paper’s analysis to dynamic load and calculation to the pavement evenness variation are fairly reliable.The project firstly analyzes dynamic load of traveling vehicle by using a vehicle vibration model of four-degree of freedom considering vehicle roll factor, and makes analysis precision largely improve. Firstly setting a interrelation between pavement evenness, dynamic load and pavement evenness variation, and making a fairly satisfied prediction to the pavement evenness variation.The research achievements analyzes and grasps developing variation law of pavement evenness, then provide a certain theory basis for reasonable formulation of pavement maintenance management criterion and promptly implementation of maintenance management measure, and provide technical assistance for the appreciation of asphalt pavement using performance and maintenance, have fairly important theory value and certainly practical significance.更多还原