中文摘要：

利用数码可视化跟踪技术、计算机信息实时处理技术和土体变形无标点量测技术,从细观层面上对不同层间系数的宽级配基料-滤层系统进行了渗透模型试验。从细观角度分析了不同层间系数的砂样在渗流过程中的水力特性、颗粒运动特点和系统破坏特征,研究了滤层的特性和管涌型土自滤自稳定的细观机理。结果表明：层间系数D15/d85s是决定滤层是否合格的最关键因素,随着比率D15/d85s的增大,系统朝不稳定的方向发展;越靠近上游的颗粒移动的越早,越小粒径的颗粒潜在的移动距离越大;除了层间系数,加压速率和扰动力等因素也会影响管涌的发生发展。

英文摘要：

The image visual tracing technique,real-time digital process technique and non-target measuring technique for soil deformation are applied to carry out the meso-scale model tests for base soil-filter with broadly graded sandy soil and various ratio of layer coefficients.The hydraulic features of system,motion feature of removal particles and failure characteristics of system in the process of seepage are analyzed from the meso-scale view point.Furthermore the proprieties of filter and mechanism of self-filtering and self-steadying of piping-typed soils are also studied.The results show that layer coefficient which expressed by the grain ratio D15 /d85s is the most critical factor for determining whether the filtering layer is qualified.With the increase of the D15 /d85s the system tends to instable.The particles located closer to the upper reach of the piping move earlier and the smaller size particles have larger potential movement distances.In addition to the layer coefficient,the compression rate and disturbance force and other factors also influence the occurrence and development of piping.