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为了研究移动荷载下路面结构内部细观结构的响应,采用离散元方法进行了多尺度路面结构移动荷载响应的分析.建立了柔性基层沥青路面典型结构的离散元模型,并计算了移动荷载作用下沥青层底的应力和应变,通过与已有经典计算程序荷载响应计算结果的比较,验证了所建立的离散元模型.以该离散元模型为基础,在沥青混凝土结构层的底部,采用尺度较小的离散单元描述粗集料的体积含量、分布特征以及空隙大小等细观结构,以此建立路面结构的多尺度模型.对路面结构宏观响应与细观结构的荷载响应进行了比较分析,并分析了沥青砂浆劲度对细观结构处荷载响应的影响.结果表明:粗集料与沥青砂浆界面位置的拉应力均值和离散系数均大于沥青砂浆内部;荷载引起的应力和应变在沥青砂浆内部和界面内部均存在不均匀分布;沥青砂浆的劲度越大,沥青混凝土内部的荷载响应分布越趋于均匀.
In order to study the response of meso-structure in pavement structure under moving loads, the discrete element method is used to analyze the moving load response of multi-scale pavement structure.The discrete element model of typical structure of asphalt pavement with flexible base is established and the influence of moving load The stress and strain at the bottom of asphalt layer are compared with those of the classical calculation program to verify the discrete element model established.According to the discrete element model, The small discrete units describe the volume content, distribution characteristics and the size of the gaps in the coarse aggregate so as to establish a multi-scale model of the pavement structure. The macro-response of the pavement structure and the load response of the meso-structure are compared and analyzed. The effect of asphalt mortar stiffness on the load response of meso-structure was analyzed. The results show that the mean value of tensile stress and the dispersion coefficient at the interface between coarse aggregate and asphalt mortar are greater than that of asphalt mortar. The stress and strain caused by load are in the interior of asphalt mortar And the interface are unevenly distributed; the greater the stiffness of asphalt mortar, internal asphalt concrete The distribution of load response becomes more uniform.