土工合成材料与土界面的细观研究

 利用颗粒流程序(PFC2D)对土工合成材料的拉拔试验进行模拟，着重从细观角度来分析土工合成材料与土的接触界面。通过室内拟合试验，选取和校准离散元的细观参数，土工合成材料用平行黏结模拟，土颗粒采用由3个圆形颗粒组成一个椭圆形团进行数值模拟。数值模拟结果表明，接触界面的厚度为6～7倍平均土颗粒直径，接触界面中的颗粒发生较大相对位移，孔隙率增大，接触数减小。PFC2D为从细观角度研究土工合成材料与土的接触界面特性的理想工具。

MESOSCOPICAL STUDY ON INTERFACE BETWEEN GEOSYNTHETICS AND SOIL

PFC2D is adopted to simulate geosynthetics pullout tests and the interface between geosynthetics and soil with emphasis on the meso-analysis. Suitable mesoscopic discrete element parameters are selected and calibrated so that the results of the simulation fit well with those of the laboratory experiment. Parallel bond is employed to simulate geosynthetics；and elliptical clump comprised of three disc particals is used as soil partical. The numerical results show that the interface thickness is to be approxiately 6 to 7 times of the average particle diameters；and the particles in the zone undergo larger relative displacement；the porosity increases，the coordination number decreases. PFC2D is one of the most perfect numerical tools to study the interface between geosynthetics and soil from mesoscopic point of view.