A Comparative Study on Consolidation of Clay for Various Loading Conditions

Settlement can be defined as the vertical, downward movement of soil due to decrease in the volume of soil and it occurs mainly in soils having low strength. Various problems encountered like settlement can cause serious problems to the structures constructed above it. New techniques are adopted to minimise these problems created by the soil like accelerating the rate of consolidation. In this project consolidation of clay under conventional, vacuum-surcharge loading providing a sand drain has been studied. Tests were conducted for various pressures of 20, 40, 50, and 80kPa with and without sand drain. From the result obtained it was found that the coefficient of consolidation and total settlement is higher for soil with sand drain. The coefficient of volume change is minimum under vacuum loading without drain. The time taken for 90 % consolidation was lesser and the settlement was higher in combined vacuum-surcharge loading having drain than without drain. Settlement increased by 1.15 times by using vertical sand drain when compared with the settlement of soil without sand drain.