Water Placing Method of Vertical Drains Based on Nonwoven Fabric

Abstract

The chemical board vertical drain method using nonwoven fabric has been spreading rapidly as a method to improve soft ground for the reasons that on land there is no disconnection of the draining section, its handling is easy, execution of work is simple and the drain can be placed at short intervals and the cost of the work is inexpensive. However, because of a problem in the cutting of the drain under water, its placing in water had not been done so far.
At this time a cutting mechanism of the draining material in water has been developed, incorporated in a nonwoven fabric (TAFNEL) drain method and its water placing method established. Draining work extending to 330, 000 meters on the sea was executed and extremely good results were obtained from the records of measurements made with the passage of time.