长大纵坡沥青路面车辆动载响应黏弹性分析

Dynamic response viscoelastic analysis of long-uphill asphalt pavement subjected to vehicle load

为研究车辆载荷作用下长大上坡沥青路面的动力响应规律，以东风EQ1108G6D13车辆作为代表车型，通过上坡车辆载荷计算模型以及研究路面的黏弹性本构关系在有限元分析中的实现，建立路面的三维瞬态黏弹性有限元模型，并进行非线性求解，分析坡度、载荷大小和环境温度变化时的动力响应规律，并根据仿真分析结果，进行动力响应现场实测试验．结果表明：随着坡度的增加，动力响应增加的幅度很小；动力响应随载荷和温度的增加有明显的增加，增加幅度较大，尤其在高温时增加幅度很大；对于所研究的路面结构，纵向剪应变最大值出现在路表下方5cm附近，横向剪应变最大值出现在路表下方5～17cm处．因此，中面层最易遭到剪切破坏，应提高其抗剪切能力．仿真数据与试验实测数据误差基本在20％以内，表明该模型能较好的模拟爬坡车辆作用下沥青路面的动力响应．

To investigate the dynamic response of long-uphill asphalt pavement suhjected to climbing vehicle load, Dongfeng EQ1108G6DI3 vehicle was selected as a representative vehicle. The load calculation model of climbing vehicle and the viscoelastic constitutive relation were achieved by finite element analy- sis to establish a three-dimensional transient finite element model of pavement. The variations of slope, load and temperature were analyzed by nonlinear solution of finite element model, and the situ strain experiment was conducted according to the simulation result. The results show that with the increasing of slope, the dynamic response increases slightly. With the increasing of vehicle load and temperature, the dynamic response is increased greatly, especially at high temperature. The maximum value of longitudinal shear strain appears 5 cm under road surface, while the maximum value of transverse shear strain concentrates 5 - 17 em under road surface. The shear destruction easily occurs at mid-surface and the anti-shear ability should be improved. The difference between simulation and experiment results is less than 20% , which illuminates that the proposed model can well simulate the mechanical behavior of pavement subjected to climbing vehicle.