半刚性基层沥青路面平整度波长研究

Study on Roughness Wavelength of Semi-rigid Base Asphalt Pavement

为了研究路面平整度波长和动荷载之间的关系,识别半刚性基层沥青路面的波长范围,选择典型高速公路和3级公路作为试验道路。以重型车辆和轻型货车作为试验车辆,采用满载和空载2种工况,在试验车辆后轴安装自主研发的无线车辆轮轴振动加速度测量仪器。现场试验获取车辆轮轴竖向振动时域特征数据,经过傅里叶变换,获得车辆振动频域特征。根据频率、车速和波长之间的关系计算划分了半刚性基层沥青路面平整度波长范围。结果表明:车轴振动加速度的标准偏差可以作为车辆动载荷的直接指标,车轴振动加速度的标准偏差随车速和路面粗糙度的增加而增加;半刚性基层沥青路面的车辆振动典型频域曲线由2个主共振频率和1个次共振频率组成;路面平整度波长可划分为4个波段:0~0.2 m极短波,0.2~1.4 m短波,1.4~5.6 m中波,5.6~100 m长波;极短波和长波对车辆振动产生动荷载影响较小,短波和中波对车辆振动产生动荷载影响较大,其中1.4~5.6 m中波对车辆振动产生动荷载的影响最大。试验结果可作为半刚性基层沥青路面平整度波长波段划分的新标准,为制订半刚性基层沥青路面平整度施工控制标准提供依据。

To study the relation between pavement roughness wavelength and dynamic load,and to identify the wavelength range of semi-rigid base asphalt pavement,the typical expressways and third-grade highways are selected as test roads.The heavy-duty vehicles and light-duty trucks are taken as test vehicles with full load and no load conditions.The self-developed wireless vehicle axle vibration acceleration measurement instrument is installed on the rear axles of test vehicles.The time-domain characteristic data of vertical vibration of vehicle axle are obtained from the field test.The frequency-domain characteristics of vehicle vibration are obtained through Fourier transform.According to the relation among frequency,vehicle speed and wavelength,the roughness wavelength range of semi-rigid base asphalt pavement is calculated and divided.The result indicates that the standard deviation of axle vibration acceleration can be used as a direct indicator of vehicle dynamic load,and the standard deviation of axle vibration acceleration increases with the increase of vehicle speed and road roughness.The typical frequency domain curve of vehicle vibration on semi-rigid base asphalt pavement consists of 2 primary resonance frequencies and one secondary resonance frequency.The pavement roughness wavelength can be divided into 4 wave bands,which are 0-0.2 m ultrashort wave,0.2-1.4 m short wave,1.4-5.6 m medium wave,and 5.6-100 m long wave.The ultrashort short wave and long wave have little influence on dynamic load generated by vehicle vibration,and the short wave and medium wave have greater influence on dynamic load generated by vehicle vibration,among which the medium wave of 1.4-5.6 m has the greatest influence on dynamic load generated by vehicle vibration.The test result can be used as a new standard for division of roughness wavelength semi-rigid base asphalt pavement,and provide a basis for formulating the construction control standard of roughness of semi-rigid base asphalt pavement.