Research Paper EFFECT OF SKIRT ON PRESSURE SETTLEMENT BEHAVIOUR OF MODEL CIRCULAR FOOTING IN MEDIUM DENSE SAND

This paper presents the result of load tests conducted on a circular footing resting on confined sand to study the influence of cylindrical skirts with different heights and diameters in medium dense sand. Model test were conducted on circular footing placed centrally in medium dense sand in model tank without and with skirts in different combinations of height and diameters. The comparison was made between the results of unconfined case and confined case. It is concluded that the pressure corresponding to 5 mm settlement (i.e. 10% S/D ratio), increases appreciably by confining the sand with skirts and it is due to that skirt restricts the lateral displacement of the sand underneath the footing, thus resulting in appreciable improvement. The relative density of sand is kept at 50% to study the phenomenon for medium dense sand. For the case of skirts of small diameters the effect was small and reaches a optimum value for a specific diameter of skirt with respect to diameter of pile and again as skirt diameter increases appreciable this phenomenon loses its significance .

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