BEHAVIOR OF SQUARE FOOTING RESTING ON REINFORCED SAND SUBJECTED TO INCREMENTAL LOADING AND UNLOADING

Basavaraj Hotti, P.G. Rakaraddi, Sudharani Kodde

Abstract: The foundations of various structures are subjected to cyclic loading in addition to static loading in many situations. This paper presents the results of laboratory model tests on square footings supported on geogrid reinforced sand bed under incremental loading and unloading conditions for different densities of sand bed and U/B ratio. The incremental values of intensity of loads (loading, unloading and reloading) were applied on the footing to evaluate the response of a square footing and also to obtain the value of elastic rebound of the footing corresponding to each cycle of load. The effect of sand for the density 1.59 gm/cc, 1.69 gm/cc, and 1.79 gm/cc and for different U/B ratio of 0.2, 0.4, and 0.6were investigated on ultimate bearing capacity and the dynamic properties such as coefficient of elastic uniform compression Cu, coefficient of elastic uniform shear Ct , coefficient of elastic non-uniform shear C? and the coefficient of elastic non uniform compression Cf. The results shows that the value of ultimate bearing capacity and the value of Cu, Ct , Cf and C? of sand were increased by increasing the density of sand and with the increase of U/B ratio up to 0.4. The results of ultimate bearing capacity and values of dynamic properties (Cu, Ct , Cf and C?) for reinforced sand are greater than unreinforced sand bed.

Keywords: Geogrid, coefficient of elastic uniform compression, coefficient of elastic uniform shear, coefficient of elastic non-uniform shear, coefficient of elastic non uniform compression

DOI: https://doi.org/10.15623/ijret.2014.0318011