Radial Consolidation of Soft Kaolinitic Clay Using Vertical Jute Geo-Drain

Abstract

The need to utilize the poor soil for foundation support and earth work construction increases day by day, amongst the various ground improvement technique the radial consolidation of soft clays by vertical geo-drain is one of the ground improvement technique. Under this technique the rate of settlement is alternated by vertical prefabricated geo-drain because consolidation time varies as square of drainage path length and also most deposits have greater permeability in horizontal direction then in vertical direction. The installation of vertical geo-drains intercepts horizontally flowing pore water and reduces the drainage path thus increasing the rate of consolidation manifold. Installation of drains is either round or flat band drains. The aim of the present investigation is to explore the fabrication of an efficient geo-drain for accelerating the consolidation settlement of clayey soils. A pre-fabricated vertical jute geo-drain is developed by encasing polyamide bonded with polyester filter fabric. The hydraulically pressurized Oedometer with central geo-drain is employed in present investigation and Cvr value is determined using both the settlement and pore pressure reading. The value of Tvr50 for n = 12.09 is used for determination of Cvr from settlement readings. The experimental isochrones using the pore pressure readings at radial co-ordinates are drawn and compared with theoretical ones. The gain in strength of clay because of consolidation is also examined. The geo-drain employed in present investigation has increased the effective rate of pore pressure dissipation and thus allowed easily consolidation for a particular construction loading which signifies its use in field application, where the rate of construction is required to be compatible with time schedule available. The use of jute makes it possible in saving the cost over the other available geo-drain. Encasement of polyamide bonded with polyester filter helps in increasing the durability of jute