A numerical test method of California bearing ratio on graded crushed rocks using particle flow modeling

作     者：Yingjun Jiang Louis Ngai Yuen Wong Jiaolong Ren 

作者机构：Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang'an University School of Civil and Environmental Engineering Nanyang Technological University School of Transportation Southeast University 

出 版 物：《Journal of Traffic and Transportation Engineering(English Edition)》 (交通运输工程学报（英文版）)

年 卷 期：2015年第2卷第2期

页      面：107-115页

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the Program for New Century Excellent Talents in University (NCET-08-0749) Fundamental Research Funds for the Central Universities (CHD2012JC054) 

主　　题：Graded crushed rocks Particle flow modeling California bearing ratio Numerical test Micro mechanical parametersMesoscopic mechanism 

摘      要：In order to better understand the mechanical properties of graded crushed rocks （GCRs） and to optimize the relevant design, a numerical test method based on the particle flow modeling technique PFC2D is developed for the California bearing ratio （CBR） test on GGRs. The effects of different testing conditions and micro-mechanical parameters used in the model on the CBR numerical results have been systematically studied. The reliability of the numerical technique is verified. The numerical results suggest that the influences of the loading rate and Poisson＇s ratio on the CBR numerical test results are not significant. As such, a loading rate of 1.0-3.0 mm/min, a piston diameter of 5 cm, a specimen height of 15 cm and a specimen diameter of 15 cm are adopted for the CBR numerical test. The numerical results reveal that the GBR values increase with the friction coefficient at the contact and shear modulus of the rocks, while the influence of Poisson＇s ratio on the GBR values is insignificant. The close agreement between the CBR numerical results and experimental results suggests that the numerical simulation of the CBR values is promising to help assess the mechanical properties of GGRs and to optimize the grading design. Be- sides, the numerical study can provide useful insights on the mesoscopic mechanism.