Abstract

A study of the behavior of two types of geogrids used to reinforce sandy soil under strip footings. Three layers of Netlon CE121 and Tensar SS2 geogrid were used. A series of a laboratory tests were performed to compare the estimate a bearing capacity of sand with and without using geogrids. The aim of the study is to measure the strain and elongation occurring in the ribs of Tensar SS2 geogrid only. TML strain gauges and other required accessories are used for this purpose. The soil is loaded with a rate of loadings 1 mm/s in order to simulate a static loading case with relative density of sand as 71.8 % using raining technique. It is found that the use of geogrids gives a bearing capacity with geogrid to bearing capacity without geogrid (BCR) of 1.9 and 2.5 for Netlon CE121 and Tensar SS2 respectively. The results founded also that the strain and elongation decrease gradually when the depth under footing increases as well as the distance from the centerline of footing. The strain in geogrid r ibs approaches zero at a depth of about the width of footing (B) and a distance of about 3.6B from the centerline of footing. The strain and elongation have vanished in the third layer located at depth B beneath the footing.