基于PFC3D黏性与无黏崩滑土体运动过程对比分析

Comparison Analysis of the Motion Process About Viscous and No-viscous Landslip-collapse Soil Based on PFC3D

大多数岩土体崩滑后形成由粗颗粒和黏性填隙介质组成的黏性崩滑体。为分析黏性填隙介质对运动过程的影响,利用MCR301,测定容重为1.360 g/cm3成都黏土法向黏连力和切向剪切抗力。利用PFC3D构建崩滑土体运动数值模型,并将崩滑土体试样划分为5个部位,用设定颗粒代表崩滑土体不同部位。通过对比分析颗粒间切向、法向黏连强度为200 Pa和无黏情况下,不同部位颗粒位置、速度随时步演化过程,分析结果表明:黏连强度改变崩滑土体启动运动模式,在200 Pa为推移式启动模式,无黏情况下为溜滑启动模式;黏性条件下颗粒峰值速度较无黏条件下小,而碰撞频率较无黏条件下高,速度波动幅度大。

In order to analyze the influence of gap filling viscosity to the motion of landslip-collapse soil,the normal-force and tangential-force of Chengdu clay with the density of 1.360 g / cm 3 were measured by MCR301 Rheometer.Using the PFC3D,the numerical model of landslip-collapse soil was constructed and divided into five parts.Every specific particle represented different parts of landslipcollapse soil.The comparative analysis of motion process about different parts particles under set normal and tangential bond strengths(0 Pa,200 Pa) showed that the starting form of landslip-collapse soil was push type when the bond strength was set to 200 Pa,but was skid type when the bond strength was 0 Pa.The peak velocity of particle at 200 Pa was smaller,while the collision frequency and velocity fluctuation amplitude were higher than the values at 0 Pa.