非均布动荷载作用下车速对粘弹性沥青路面寿命的影响

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ANSYS 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.

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

To study the ef fect o f t ruck v elocity o n the life of asphalt pav ement wi thout taking the ef fects ofov erloading into account , a 3-D finite element analysis ( FEA) v isco-elastic road model w as establishedbased o n the lay ered theory wi th AN SYS sof twa re. Then the deflectio ns of the pavement under the no n-unifo rm di st ributed dynamic loads were calculated and analy zed, and the li fe ra tios ( LR) at di fferent velocitiesw ere compared wi th the axle ex chang e methods. The results show that the def lections caused by dynamicloadings a re bigg er than tha t caused by the sta tic loading s when the veloci ties are betw een 10km /hand 32 km /h, that the dy namic def lection is 22. 4% la rg er than the static o ne w hen the v eloci ty i s 17 km /h a nd in the case where the service life of the pav ement is 61. 5% sho rter tha n the desig n life. Traf fic investigatio n a t Hefei-Na njing f reeway shows that wi thin tw o kilometers o f the f reew ay ent rance, o ne kilometerin f ro nt of to ll pla za , on the v ehicle climbing road sectio n a nd o n the heav y traf fic bridg e, the velocitiesof most heav y t rucks and lorries are wi thin the unexpected t rav el speed, which can bring sig nificant influence o n the service life of the aspha lt pav ement