非均布动荷载作用下车速对粘弹性沥青路面寿命的影响

Effect of truck velocity on life of visco-elastic asphalt pavement under non-uniform distributed dynamic load

在不考虑超载情况下,为探求重载货车行车速度对沥青路面使用寿命的影响,采用层状体系理论,建立AN SYS 3-D有限元粘弹性路面结构模型;针对不同车速及非均布动荷载作用下路表面弯沉值的变化进行了计算和分析,并利用轴载换算方法对仿真结果在不同车速下的寿命比进行了比较。结果表明,当重载车速在10-32 km/h之间时,路面的动态弯沉值显著大于静态弯沉值;当车速在17 km/h时,动态弯沉比静态弯沉大22.4%,此时沥青路面的实际使用寿命比设计寿命缩短将近61.5%。在合宁高速公路上开展的交通调查结果显示,高速公路入口2 km内、收费站前1 km内、车辆爬坡路段及交通繁忙的大桥上,大多数重车的车速都处于不利行车速度,对路面实际使用寿命的影响非常显著。

To study the effect of truck velocity on the life of asphalt pavement without taking the effects of overloading into account, a 3-D finite element analysis （FEA） visco-elastic road model was established based on the layered theory with ANSYS software. Then the deflections of the pavement under the non-uniform distributed dynamic loads were calculated and analyzed, and the life ratios （LR） at different velocities were compared with the axle exchange methods. The results show that the deflections caused by dynamic loadings are bigger than that caused by the static loadings when the velocities are between 10km/h and 32 km/h, that the dynamic d＇efleetion is 22.4G larger than the static one when the velocity is 17 km/ h and in the case where the service life of the pavement is 61.5% shorter than the design life. Traffic investigation at Hefei-Nanjing freeway shows that within two kilometers of the freeway entrance, one kilometer in front of toll plaza, on the vehicle climbing road section and on the heavy traffic bridge, the velocities of most heavy trucks and lorries are within the unexpected travel speed, which can bring significant influence on the service life of the asphalt pavement.