NATURAL GEOSYNTHETIC DRAIN FOR SOIL IMPROVEMENT

A geosynthetic vertical drain known as Fibredrain was developed using organic fibres from jute and coir to improve thick soft clay deposits. In addition, it was required to withstand the application of high energy impact on surface fills implemented as a part of soil improvement works. Some laboratory tests conducted to examine the relevant properties of this drain under simulated field conditions are presented. The drain was used in several construction projects in. the southeast Asian region involving reclamation fills overlying marine clay, dynamic replacement and mixing (DRM) method of treating peaty soils underlain by fluvial clays and housing projects built on mine tailings. The back analysis of field behaviour of the drain shows that it has adequate discharge capacity for consolidation of highly plastic clays; its effectiveness lasts for observed periods of over 2 years and its function as a vertical drain is unimpaired when used in conjunction with high energy impact application. The relatively low cost of manufacture using indigenous material and local labour makes this drain attractive in countries where jute and coir are abundant as well as where ecological considerations are important as this drain is biodegrable.