轴重与胎压对半刚性基层沥青路面动力响应影响理论研究

Theoretical Study on Effect of Axle Weight and Tyre Pressure on Dynamic Response of Semi-rigid Base Asphalt Pavement

采用多目标参数评价方法,分析了车辆轴重和胎压对路面结构动力响应的影响,建立移动荷载下粘弹性层状体系动力学模型。结果发现,路面结构动力响应随着轴重和胎压的增加而增加,轴重和胎压对路面结构的动力响应具有耦合性。0.7 MPa胎压下,轴重达到250 kN时,面层底部弯拉应变和土基顶部竖向压应变均小于永久性路面结构设计指标,可作为校核指标;面层底部水平剪应变远大于层底弯拉应变,可作为半刚性基层沥青路面动态设计的主要设计指标。因此,提高面层与基层之间的粘结强度是提高半刚性基层沥青路面结构使用寿命的关键。

A dynamic model for calculating the dynamic response of multi-layer visco-elastic system under moving load was set up, and the influences of axle load and tire pressure on the dynamic response of the semi-rigid base asphalt pavement were analyzed based on multiobjective evaluation parameters.The results show that （1） the dynamic response increases with the increasing of axle load and tire pressure; （2） under 0.7 MPa tire pressure and 250 kN axle load, the maximum strains of the semi-rigid pavement, which include the horizontal tensile strain at the bottom of the AC layer and the vertical compressive strain at the top of the roadbed, are still lower than the corresponding design limitation for the long-life pavement; （3） the horizontal shearing strain at the bottom of the AC layer is several times larger than the horizontal tensile strain. So the horizontal shearing strain at the bottom Of the AC layer should be taken as a main design control index for the semi-rigid asphalt pavement, and the horizontal tensile strain at the bottom of the AC layer and the vertical compressive strain at the top of the roadbed should be taken as checking indexes. Increasing the coherence strength between the base layer and the AC layer is the key technique to increase the service life of the asphalt pavement.