层间接触位置和状态对沥青路面力学指标的影响

Influence of Interlayer Contacting Surface and Condition on Mechanical Indexes of Asphalt Pavement

为研究沥青路面层间接触位置和接触状态对路面结构内力学指标的影响,选择典型的高速公路半刚性基层路面结构,利用BISAR3.0软件计算分析不同层间接触位置时的路面力学指标,并探讨不同基面层接触状态下沥青路面力学响应和疲劳寿命的变化规律。结果表明:面层与面层、面层与基层、基层与底基层之间在完全光滑时对拉应力、拉应变、剪应力影响显著,弯沉受层间接触位置的影响变化不大;随着基面层间滑动系数的增加,路面结构内的应力、应变逐渐增大,在完全滑动时下面层底的拉应力、剪应力和拉应变分别是完全连续时的2.93倍、2.45倍和69.36倍;在基面层间滑动系数小于0.6时沥青路面的疲劳寿命降幅较小,随后降幅逐渐增大,当基面层间完全光滑时,疲劳寿命较完全连续时下降44.5%。

In order to study the influence of interlayer contacting surfaces and condition on mechanical index of asphalt pavement,the paper selected typical semi-rigid base pavement structure of expressway.The pavement mechanical indexes under different contacting surface were calculated by BISAR 3.0.The changing laws of asphalt pavement mechanical indexes and fatigue life under different contacting condition between base and surface course were discussed.The results show that：the influence of smooth condition between surface courses,surface course and base,base and subbase on tensile stress, tensile strain and shear stress is prominent.Deflection is slightly affected by different interlayer contacting surface.The stress and strain of pavement increase gradually with the increasing of sliding coefficient between base and surface course.The tensile stress,shear stress and tensile strain of following layer under completely sliding condition are 2.93 times,2.45 times and 69.36 times of fully continuous condition respectively.Decreasing range of fatigue life is small when the sliding coefficient between base and surface course is less than 0.6,then decreasing range increases.When the base and surface course are in completely smooth,the fatigue life declines 44.5%.