Role of jute geotextile/slurry interface friction on the bearing capacity of clay slurry

Abstract

The layered clay-sand scheme of land reclamation depends on the successful formation of sand seams sandwiched between hydraulically placed layers of marine clay slurry to provide shorter drainage paths for rapid clay consolidation during surcharge application. It is anticipated that a low-cost jute geotextile placed on a clay slurry surface without anchorage will expedite construction of sand seams by providing support for the thin sand layers and preventing penetration of sand into the clay slurry. In this application, the interface friction between the very soft clay slurry and the jute geotextile plays a major role in determining the support for the thin sand seam. This paper discusses measurement of the jute/slurry interface friction by incremental vertical penetration of a thin, end-weighted jute sheet under an incremental load to obtain the interface stress value under a quasi-static condition. The effects of sheet width and sheet type were investigated and found to be negligible on the measured interface friction for the clay slurry water content range tested. The results of the interface friction for the 500 g/m2 jute geotextile is then applied to a rectangular loaded area with a jute base on clay slurries of 150 to 300% water content. These water contents are the likely range of values to be encountered in field applications. The load test results indicate that the measured bearing capacity for the jute on clay slurry is about 5.5 to 6.5 times the interface friction, which is in close agreement with typical bearing-capacity factors used in a shallow foundation on clays.