摘要
粒间胶结的存在导致天然结构性土体具有独特的宏观变形和强度特性。为了研究法向加载条件下三维胶结颗粒的接触破坏规律及尺寸效应,采用有限元法模拟了理想球形胶结颗粒的法向接触力学试验,并将有限元与离散元的模拟结果进行了对比,分析了不同直径比和厚宽比情况下胶结颗粒抗拉压强度的变化规律,得到了胶结颗粒法向接触强度与胶结尺寸参数的定量关系。结果表明:胶结物的直径比和厚宽比显著影响胶结颗粒法向抗压强度,厚宽比占主导作用,抗压强度随着厚宽比增加显著降低;但胶结颗粒抗拉强度的尺寸效应不显著。
The presence of inter-particle bonds leads to the unique macroscopic deformation and strength characteristics of natural structural soils. In order to study 3D cement particle contact failure regularity and size effect under the normal loading conditions, the contact mechanics test of ideal spherical particle cementation was simulated by finite element method. The results of the finite element simulation and those of discrete element simulation were compared. The finite element method was used to simulate normal contact response of two spheres sandwiching cementation in order to reveal the size effect on normal resistance of bonded spheres. The simulation results of finite element were compared with those of discrete element. The rule of compression/tension resistance of the bonded spheres was analyzed under different values of two dimensionless geometric parameters of the bond, i. e. , diameter ratio and thickness-to-width ratio of the bond. Quantitative relationships between contact strength and cement size parameters were obtained. The results show that the compressive resistance of the bonded spheres is highly affected by the diameter ratio and the thickness-to-width ratio of the cementaneous material, and the thickness-to-width ratio plays a dominant role. The compressive resistance of the bonded spheres significantly decreases as the thickness-to-width ratio of the bond increases, while the size effect of the cement particle tensile strength is not significant.
出处
《重庆交通大学学报（自然科学版）》
CAS
北大核心
2017年第7期66-72,共7页
Journal of Chongqing Jiaotong University(Natural Science)
基金
国家自然科学基金项目(415722675
51239010
51579178)
国家科技支撑计划课题(2013BAB06B02)
流域水循环模拟与调控国家重点实验室自主研究课题(2015ZY05)
关键词
岩土工程
胶结材料
接触力学
有限元模拟
尺寸效应
geotechnical engineering
cementaneous material
contact mechanics
finite element simulation
size effect
