BEHAVIOR OF SHELL FOUNDATIONS ON SANDY SOIL REINFORCED WITH A CIRCULAR GEOGRID

Abstract

The purposes of this study are to investigate and evaluate the benefits of using geogrids as a circular pipe of two different lengths of (20 cm and40 cm) under the footing base in the improvement of bearing capacity and settlement in terms of the bearing capacity ratio (BCR) and the settlement reduction factor (SRF). A load-frame assembly was designed for the experimental work. Two types of the aluminum rigid foundation were used; flat-footing and shell footing of dimensions (20× 20 cm) and different angles of (20˚, 30˚, and 45˚) for the shell. The sand Rainer device technique was used to fill the tank to obtain a homogenous sandy soil. The result shows that using a circular geogrid with a length (H=20cm) leads to an increase in the BCR by (14-41)% higher than that for unreinforced sand while increasing the geogrid length to 40 cm leads to increase BCR by (6-19)% . The SRF for a certain footing decreases with decreasing the geogrid length from 40 cm to 20 cm by (11-21) %. This may be related to the punching effect caused by the longer geogrid through the loose sand stratum.