Effect of geometrical sand drains on consolidation of soft contaminated marine clays using Oedometer

The object of the present study is to determine consolidation parameters of contaminated marine kaolinitic clay with inward radial flow using geometrical shape vertical sand drains under constant magnitude of constant pressure. Efficacy of sand drains of different diameters and shapes like circular, band, tripod and plus shape keeping same surface area are modeled in laboratory using Oedometer and its effect to accelerate compressibility by draining lechate is found using isochrones. The optimum diameter and geometry of sand drain is investigated using 'n' values (ratio of zone of influence to the diameter of drain) equal to 11.04, 16.93 and 21.71 using 254mm size modified hydraulically pressurized Oedometer. Basic aim of this paper is to evaluate mechanics of pore water pressure of marine clay using isochrones drawn for vertical drains. Author's theoretical solution based on isochrones is fitted with experimental results to compute degree of consolidation and results show a fair agreement between measured and predicted values. Circular shape sand drain can be predominately utilized for consolidation of contaminated marine clays with dual advantage.