垂直排水法中非织造布土工袋和机织土工袋的比较研究

传统的网袋排水法是先将套管在可压缩土壤中打入一定深度以形成排水道 ,然后将圆筒状鱼网机织袋放置入套管中 ,并用砂填充网袋 ,最后将套管取出。通过对 4种不同规格的机织袋和非织造布袋进行现场试验 ,研究其在施工中的性能。采用砂石、轮胎碎料、石屑和煤灰作填充材料。文章探讨了不同网袋的适用性 ,介绍了一种旨在防止网袋在套管中发生扭曲并保证排水道畅通的革新技术。这种方法的特点是采用专门设计的导板和直接接触套管管壁的抗扭曲杆 ,最后通过与传统网袋排水法的比较来验证其有效性。

Comparison of Nonwoven and Woven Geotextiles as Packs for Vertical Drain Method

In the conventional packed drain method, a drain column is constructed in compressible soil by driving a casing to a designed depth, placing a cylindrical fish net woven fabric pack (or bag) inside the ca sing, filling the pack with sand, and pulling out the casing. Four different types of nonwoven and woven fabric packs were made and their performance during the construction was studied through a field test. As filling materials, sand, scrap tire,rock powder,and bottom ash were used. Their applicability with respect to the different packs was investigated. An innovative method was introduced which was aimed to prevent the pack from being twisted inside the casing and thus to assure the soundness of drainage column. This method employs a specially designed guiding plate and an anti twisting rod attached on the inner surface of the casing. The effectiveness of this method was evaluated as compared to that of the conventional packed drain method.