THE MEASUREMENT OF INTERFACE FRICTION BETWEEN A JUTE GEOTEXTILE AND ACLAY SLURRY

The layered clay-sand scheme proposed by Lee et al. has been shown to be feasible for land reclamation in sand-scarce country. Although the layered clay-sand scheme has great potential as a means of saving sand fill in replacing scarce sand by cheap marine clay available in the s urrounding seabed, practical problems exist in its implementation. The most difficult part of the scheme is to form thin sand-drainage layer s on top of a very soft clay slurry without losing too much sand mater ial into the clay. This can only be accomplished by careful spreading of thin sand layers (of less than 5 cm) on the clay slurry when it has reached a water content below 200%. From the process of self-weight s edimentation and consolidation above, it takes a very long time to ach ieve such consistency from an initial deposition water content of 500- 600%. It is therefore necessary to investigate the use of a low-cost g eotextile (such as a jute fabric, which can support the formation of t hin sand layers on top of the clay slurry at higher water content, to shorten the waiting period before sand-spreading, as well as to save s and fill by reducing sand penetration into the clay slurry. It is prop osed that the jute fabric is placed on top of the clay slurry before c areful sand-spreading. To aid the use of jute fabric for this purpose, an investigation is carried out to determine the interface friction b etween a jute geotextile and a clay slurry at various water contents b y means of a vertical-plate-penetration test that is described in this paper.