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传统的路面力学计算并未考虑温度沿路面深度方向的非均匀性和变温过程对沥青混凝土劲度模量的影响,使理论计算结果与实际状况之间的差异较大。为此,通过数值解法同时考虑以上两个因素,对青藏公路典型路面结构不同温度分布下的力学响应进行全面的计算分析。结果表明:一天时间内,在标准荷载作用下,路面结构在沥青混凝土面层平均温度最高时刻的最大竖向位移比温度最低时刻高约14.5%;轴向及行车方向的弯拉应力分别增大6.4%和6.7%;竖向剪应力增大12.0%左右,而水平剪应力则增大33.9%。这说明沥青混凝面层的温度及其分布对路面结构力学响应有较大影响。青藏高原多年冻土地区温度变化幅度较大、变温频繁,因此,在沥青混凝土路面结构设计中应充分考虑温度及其分布的影响。
The traditional calculation of pavement mechanics does not consider the influence of the temperature inhomogeneity in the depth direction along the pavement and the effect of temperature changing process on the stiffness modulus of asphalt concrete, so the difference between the theoretical calculation results and the actual situation is larger. Therefore, by numerical solution and considering the above two factors at the same time, a comprehensive calculation and analysis of the mechanical response of the typical pavement structure under different temperature distributions on the Qinghai-Tibet Highway is carried out. The results show that under the standard load, the maximum vertical displacement of pavement structure at the highest average temperature of asphalt concrete surface is about 14.5% higher than the lowest temperature in one day. The bending stress in both axial and traffic directions increases 6.4% and 6.7%; vertical shear stress increased by 12.0%, while horizontal shear stress increased by 33.9%. This shows that the temperature of asphalt concrete surface layer and its distribution have a great influence on the mechanical response of pavement structure. The permafrost region on the Qinghai-Tibet Plateau has a large temperature change range and frequent temperature changes. Therefore, the temperature and its distribution should be fully considered in the design of asphalt pavement structure.