不同季节倒装结构沥青路面温度场和温度应力分布规律研究

Study on Temperature Field and Temperature Stress Distribution of Inverted Asphalt Pavement in Different Seasons

为了揭示不同季节倒装结构沥青路面温度场和温度应力的分布规律,结合试验路段的实测数据,确定下基层底面的温度值。应用ABAQUS有限元软件,在沥青路面下基层底面设置温度边界条件,模拟了倒装结构在不同季节温度场变化的全过程,通过温度传感器的实测数据验证有限元模拟的正确性;应用有限元模型分析倒装结构冬季、春季及夏季的温度场和温度应力,确定了倒装结构的不利区。分析结果表明:春季和冬季面层温度小于下基层温度,温度趋于恒温,由此确定下基层底面的边界条件;通过ABAQUS有限元软件对沥青路面结构进行温度场分析,发现考虑边界进行分析是符合实际的,趋势上与实测数据基本一致;倒装结构的不利区出现在中面层和上面层,不利区位于距道路表面0~10 cm。从层位看,不同季节的温度应力分布规律相同,级配碎石层温度应力最小,面层次之,水泥稳定碎石基层温度应力最大。从时间看,夏季面层温度应力最大值为0.45 MPa,冬季面层温度应力最大值为0.94 MPa。

In order to reveal the distribution of the temperature fields of an inverted structure asphalt pavement in different seasons,the temperature values of the subbase are determined based on the measured data.Based on ABAQUS finite element simulation,the temperature field simulation of the inverted structure asphalt pavement is carried out by setting temperature boundary conditions on the subbase of the asphalt pavement,which is verified by referring to the test data of temperature sensors.And then,the temperature fields and temperature stress of asphalt pavement in winter,spring and summer are analyzed,and the unfavorable region of the inverted pavement structure is determined.It is found that the temperature of the surface is lower than the subbase and the latter tends to be constant in winter and spring,then the boundary conditions of the subbase are determined.The numerical results agree well with the measured data,and it shows that it is realistic to take boundary conditions into consideration.The unfavorable region of the inverted pavement structure is the mid-layer and the upper layer,which is located 0~10 cm away from the pavement surface.From the perspective of structural layer,the distribution of temperature stress in different seasons is the same,and the temperature stress of graded crushed stone layer is the smallest,followed by surface layer,and the temperature stress of cement stabilization crushed stone base is the largest.In addition,in terms of different seasons,the maximum temperature stress of surface layer in summer and in winter are 0.45 MPa and 0.94 MPa,respectively.