透水沥青混合料车辙试验离散元仿真

柴荣山¹，董震¹，单景松²，倪效学¹，王延忠¹

1.山东省公路桥梁建设集团有限公司，山东 济南  250013；2.山东科技大学土木工程与建筑学院，山东 青岛  266590

摘要：为分析车辙对透水沥青混合料内部空隙的影响，以透水沥青混合料PAC-13为研究对象，进行按级配上限及级配中值成型的沥青混合料试件的车辙试验，得到轮迹处的车辙及空隙率的变化规律；基于车辙试验数据，采用离散元软件PFC 2D，从细观角度建立透水沥青混合料离散元颗粒仿真模型，分析透水沥青混合料车辙产生过程中内部空隙及颗粒间接触力的变化规律，并考虑试件厚度对空隙率的影响。研究结果表明：车辆荷载作用处沥青混合料空隙率变化比其他部位大；在相同荷载作用下，级配中值沥青混合料的空隙率变化比级配上限沥青混合料小；级配上限沥青混合料的模型厚度增大，空隙率变化减小，颗粒间接触力向下传递的趋势降低，且车辙板底部所受颗粒间接触力较小；厚8 cm的车辙板在荷载位置的空隙率变化较大，且随距表面距离的增大，空隙率变化幅度减小。

关键词：透水沥青混合料；车辙试验；离散元法；空隙率

Discrete element simulation of wheel rutting test for permeable asphalt mixture

CHAI Rongshan¹, DONG Zhen¹, SHAN Jingsong², NI Xiaoxue¹, WANG Yanzhong¹

1. Shandong Road and Bridge Construction Group Co., Ltd., Jinan 250013, China; 

2. School of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao 266590, China

Abstract: To analyze the influence of ruts on the internal voids of permeable asphalt mixtures, with the permeable asphalt mixture PAC-13 as the research subject, rut tests are conducted on asphalt mixture specimens formed according to the upper limit and median particle size distribution. The variation of ruts and void ratio at the wheel track are obtained. Based on the rut test data, the discrete element software PFC 2D is used to establish a discrete element particle simulation model of permeable asphalt mixtures from a microscopic perspective. The study analyzes the variation of internal voids and interparticle contact forces during the formation of ruts in permeable asphalt mixtures, taking into account the effect of specimen thickness on void ratio. Research results indicate that the void ratio in asphalt mixtures changes more significantly at the wheel load application area than in other parts. Under the same load, the void ratio change in asphalt mixtures with median particle size distribution is smaller than that in mixtures with upper limit particle size distribution. As the model thickness of asphalt mixtures with upper limit particle size distribution increases, the change in void ratio decreases, and there is a lower trend in the transmission of interparticle contact forces downward. The interparticle contact forces at the bottom of the rut board are relatively small. A rut board with a thickness of 8 cm shows a significant change in void ratio at the load position, and as the distance from the surface increases, the magnitude of void ratio changes decrease.

Keywords: permeable asphalt mixture; wheel rutting test; discrete element method; void ratio