A study on inter-particle contact behaviors and micro contact models of coarse-grained soil
WANG Zihan1，WANG Pengju1，JING Xiaokun1，ZHOU Jian2，XIAO Chengzhi1
(1. School of Civil and Transportation Engineering，Hebei University of Technology，Tianjin 300401，China；
2. College of Civil Engineering，Tongji University，Shanghai 200092，China)
Abstract：The inter-particle contact of coarse-grained soils consist of limestone is simplified as point-surface contact. The particle contact models of coarse-grained soils are obtained through experimental investigation on the normal and tangential contact properties. The large shear tests of coarse-grained soils are simulated numerically with the discrete element method(PFC) using proposed micro contact models. The contact models and micro parameters are verified by comparing simulated results with measured data. The contact behaviors and contact models of coarse-grained soils are further discussed. The results show that the relationship between contact forces and displacements are fitted with power functions with an exponent less than 1. In order to measure the tangential contact stiffness，the tangential force corresponding to the tangential displacement of 5mm is defined as the tangential contact strength，particularly，the peak tangential force is defined as the contact strength if a peak value occurs. Comparing the simulated results of large shear tests with measured data shows that the calculation errors are really small for soils with large particle diameters(2–5，1–2 cm). For the grading samples with smaller granules，the calculation errors are larger.
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WANG Zihan1，WANG Pengju1，JING Xiaokun1，ZHOU Jian2，XIAO Chengzhi1. A study on inter-particle contact behaviors and micro contact models of coarse-grained soil. , 2018, 37(8): 1980-1992.
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2018, Vol. 37 
