基于颗粒流方法的碎石渗透系数分析

渗透系数是级配碎石渗流特性的重要参数,通过颗粒流数值方法建立碎石土渗流计算模型,利用流动方程和水压方程以及碎石之间的应力变形响应进行耦合计算,得到相应级配碎石的渗流系数,数值计算结果表明:颗粒流数值分析方法(PFC)适用于模拟任意形状、大小的单元集合体,允许单元在受力过程中发生开裂和运动.颗粒流不需要给出材料的宏观参数,只需给出材料的细观参数,通过细观结果的累加,PFC可以模拟材料在宏观状态下的表象.给出的9种级配碎石的渗透性远大于规范要求的级配集料的渗透系数,渗透系数均满足工程要求,但综合比较,孔隙率较大的碎石3类较优.

Analysis for the coefficient of permeability of gravel based on the particle flow method

Permeability coefficient is one of the important parameters of the seepage characteristics of the graded gravel. The numerical calculation model of the gravel soil was established by the particle flow. The flow equation and pressure equation were used for coupling calculation with the response of deformation and stress. And the particles and fluid domain were coupled calculated, to obtain the stability condition of the whole system. The seepage was simulated to obtain the seepage coefficient of graded gravel. The results show that, the particles flow (PFC) method is suitable for the numerical analysis for gravel with any shape, size, unit assembly, and allows the element to crack and move. It is not necessarty to provide the macroscopic parameters of gravel. It only needs mesoscopic parameters, through the accumulation of mesoscopic results, PFC can simulate the appearance of the materials in the macro state. The permeability of the given 9 kinds of graded gravel are all larger than specification required, the permeability coefficient satisfy the requirements of engineering. Through the comprehensive comparison, it is better to choose the gravel 3.