考虑胶结厚度影响的结构性砂土三维胶结接触模型  

3-D bond contact model for structured sand considering influence of bond thickness

作　　者：蒋明镜[1,2] 张伏光[1,2] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土工程学报》2013年第S2期1-9,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家杰出青年科学基金项目(51025932);国家自然科学基金项目(51179128);博士点基金(20100072110048);长江学者和创新团队发展计划项目(IRT1029)

摘　　要：旨在提出考虑胶结厚度影响的三维胶结接触模型,并用于结构性砂土宏观力学特性的离散元模拟。首先,结合结构性砂土内胶结物质的力学性质与存在形式,通过简化水泥胶结铝棒接触力学特性的实测结果,提炼出用于模拟结构性砂土颗粒间胶结作用的三维胶结接触模型;其次,将该胶结模型植入三维离散元商业软件PFC3D,进行拉伸、压缩以及剪切试验的双球验证;最后,使用PFC3D对2%水泥含量的胶结砂土在不同围压条件下的三轴压缩试验进行模拟。结果表明:引入胶结接触模型的离散元数值试验可以较好地反映室内试验中胶结砂土的宏观力学特性。A 3-D bond contact model for better simulating the macroscopic mechanical behaviors of structured sand considering the influence of bond thickness is proposed. First, according to the mechanical behaviors and existence conditions of bond materials, this model is established by simplifying the contact behaviors of two aluminum rods glued together by cement. Second, the bond contact model is implemented into the 3-D DEM software(PFC3D), and verified by simulating tension, compression and shear tests on two spherical balls. Finally, a series of triaxial compression tests are performed on simulated specimens with cement content of 2% under three confining pressures, and the DEM results are compared and analyzed. The results show that the DEM tests employing the bond contact model can well capture the macroscopic mechanical behaviors of cemented sands in laboratory tests.

关 键 词：结构性砂土 胶结接触模型 胶结厚度 离散元 

分 类 号：TU441[建筑科学—岩土工程]