PFC2D在沥青路面细观结构数值分析中的应用

Application of Two - dimensional Particle Flow Code （PFC2D） Numerical Analysis of Asphalt Pavement Meso- structure

沥青混合料是由沥青和粗细集料等粒状单元共同组成的多相复合材料，目前现有的沥青路面结构设计理论均将路面结构当作均匀连续、各向同性的弹性体进行计算分析，这与沥青混合料自身属于颗粒体非连续微细观结构的实际情况不相符。采用离散元方法，运用二维颗粒流程序（PFC2D），对比分析了两种颗粒生成方法的特点及其适用条件，以开级配大粒径沥青碎石混合料（Open—graded Large Stone Asphalt Mixes，OLSM）OLSM-25推荐级配的上限为1#级配，建立了1#级配OLSM-25混合料的二维离散元模型，验证了二维离散元方法用于沥青混合料颗粒体材料数值模拟的可行性，弥补了有限元方法的不足之处，为OLSM-25的细观结构分析开辟了新的解决思路和途径。

Asphalt mixture is a kind of muhiphase composite materials composed of granular cells such as asphalt, coarse aggregate and fine aggregate, at present the asphalt pavement structure taken as uniform continuous, isotropic and elastic body are analyzed and calculated in the existing structural design theory of asphalt pavement, which is inconsistent with the fact that asphalt mixture belonging to the discontinuous particles micro -structure. In this paper, after comparative analysis on the characteristics and its applicable conditions of the two particles genera- tion methods by the discrete element method and the two -dimensional particle flow code （PFC2D）, taking the up- per limit of the recommended gradation range of Open -graded Large Stone Asphalt Mixes （OLSM -25） as 1# gra- dations, the two - dimensional discrete element model of 1 # gradation of OLSM -25 mixes is established, and then the feasibility of the two - dimensional discrete element method used in the numerical simulation of asphalt mixes composed of particle materials is verified, which not only makes up the deficiencies of finite element method, but also provides new ideas and solutions to analysis on meso - structure of OLSM - 25.