Dynamic Behavior of Marine Clay Soil Improved by Vertical Sand Drain

Abstract

Numerical, analytical and experimental studies have shown that sand drain accelerates the rate of consolidation soft clay soil by providing the drainage path, reduction in settlement, increasing bearing capacity of the soil, this paper studies influence of cyclic behavior of sand drain imposed clay soil in laboratory cyclic Tri-axial apparatus, An experimental study on the consolidate drained dynamic behavior of saturated clays in cyclic triaxial tests with a variable confining pressure is presented. Tests were conducted on artificially prepared samples of marine clay (collected from Nagapattinam), using a dynamic triaxial apparatus where the deviatoric stress and confining pressure can be varied simultaneously. cyclic loading is applied with frequency of 0.25 Hz, drained cyclic loading the developed pore pressure was allowed to dissipate, virgin clay soil alone and improved with sand drained specimens having a maximum size of 100 mm in diameter and 200 mm in height was used for the study, Test results obtained from this study show that the drained response of saturated clays is strongly influenced by the application of sand drain, in terms of pore water pressure, development speed of cyclic strain and magnitude of cyclic strength, drainage property is compared with without sand drain specimens. Studies include effect of dissipation of excess pore water pressure and cyclic strain ratio.