BEHAVIOUR OF ECCENTRICALLY LOADED FOOTINGS ON PLY SOIL

Abstract

Three dimensional tests were performed on a square (150mm x 150mm) surface footing resting on ply soil (RDFS), and subjected to vertical central and one way eccentric load. For conducting the three dimensional tests, a uniform sand was compacted in the test tank (1000mm x 1000mm x 450 depth) at a relative density 60%. Three types of reinforcement, 6 denier-20mm length, 20 denier-40mm length and 20 denier-60mm length polypropylene fibres were used. In all one hundred and three tests were conducted. The depth below the base of footing up to which the RDFS was called as relative depth of reinforcement (RD) and it was varied up to significant depth (SD). for square footings significant is taken as 2.OB, B being width of footing. The fibre contents were taken (0.5%, 1.0%, 1.5% and 2.0%) by weight of soil. In each test, loads, settlements and tilts were measured. Computations and plots were made and conclusions were drawn giving the effect of reinforcement and eccentricity of load on the bearing capacity and settlement characteristics of the footing. Three tests were conducted in submerged state and test results were compared with dry condition results for same reinforcement. In addition to this non-dimensional correlations were also obtained to predict the settlement of eccentrically loaded footings on ply soil.