堆石体应力变形细观模拟的随机散粒体不连续变形模型及其应用

STOCHASTIC GRANULE DISCONTINUOUS DEFORMATION MODEL OF ROCKFILL AND ITS APPLICATION

从细观角度建立堆石体的随机散粒体不连续变形(SGDD)模型,该模型采用蒙特卡罗法建立堆石体的随机分布模型,通过基于修正的增广Lagrangian算法的非线性接触算法模拟颗粒间的相互接触作用,可以有效模拟颗粒相互作用及尖端破坏等因素。对堆石体三轴试样进行细观数值模拟和试验验证,再现了堆石体内部的颗粒运动变形规律。数值计算结果表明,SGDD模型能够较好地反映堆石体试验的瞬时变形规律。对室内试验缩尺效应进行探讨,采用试验级配与真实级配的2组三轴堆石体试样,运用SGDD模型进行对比分析。计算结果表明,在没有考虑堆石体流变和湿化的条件下,采用原始级配的SGDD模型在相同的应力水平和围压下表现出较小的变形。

Stochastic granule discontinuous deformation（SGDD） model is presented from mesomechanical view; random distribution model of rockfill granule is built by Monte Carlo method： and nonlinear contact algorithm is presented based on modified augmented Lagrangian algorithm. SGDD model may simulate effectively interaction of rockfill granule and tip rupture. Triaxial samples of rockfill are simulated by SGDD model; and the movement and deformation processes of rockfill granule also re-emerge. The numerical calculation results show that SGDD model can simulate the instantaneous deformation process. Scale effect of laboratory test for rockfill is also discussed. Two groups of rockfill samples, a reduced scale gradation and another real one, are simulated by SGDD model. It reveals that the real scale gradation shows less deformation and higher initial modulus of elasticity under the same axial stress and confining pressure without considering creep and humidification deformations of rockfill.