轴载与速度对半刚性沥青路面动力响应的影响

Influence of axis's load and speed on dynamic response of semi-rigid base of asphalt pavement

为了研究实际车辆荷载下半刚性基层沥青路面动力响应的规律,在修筑的试验路段上,以重型运输车辆为加载设备,通过检测运动车辆下面层底部的纵向动应变和横向动应变,分析车辆轴载和速度对路面结构动态响应的影响。研究结果表明:不论是横向应变还是纵向应变,均既有拉应变状态,又有压应变状态;随着车辆行驶速度的提高,各应变分量都基本呈下降趋势,但在车辆行驶速度超过40 km/h后,变化明显减小;动应变与轴载基本呈线性关系;进行路面结构动态设计时,不但要考虑面层底部拉应变的作用,而且要考虑压应变的作用;在疲劳寿命试验时,应考虑应变比的影响,应变比不仅与速度有关,还与轴载有关。

In order to study the dynamic response of semi-rigid base of asphalt pavement under moving load, a test road is constructed. With the study of longitudinal and lateral dynamic strain on the surface layer base, the influence of vehicle axis＇s load and speed on dynamic performance of pavement structure was studied. It was found that both the lateral strain and the longitudinal strain have the tension strain and the compressive strain. Enhances along with the speed, each strain component assumes downtrend, but it changes little when the speed is over 40 km/h. The dynamic strain and the axis＇s load assume the linear relationship basically. It is proved that there is quite difference of the stress strained condition between that under the actual transportation loads and that under the static loads. When carrying on the dynamic design, both the functions of the tension strain and the compressive strain on the surface layer base must be considered, and when carrying on fatigue experiment, strain ratio should be considered. The strain ratio is related with not only the speed but also the axis＇s load. 2 tabs, 10 figs, 10 refs.