INTERACTION OF MULTIPLE HELICAL EARTH ANCHORS EMBEDDED IN GRANULAR SOIL

This experimental program studies the behavior of groups of helical ea rth anchors embedded in granular soil. This was performed by the use o f laboratory and field anchor-pullout tests. A literature review of ex isting anchor-capacity theories and related material is presented. Lab oratory and field group-anchor pullout tests were conducted to study t he mutual interaction behavior of the individual anchors. Results indi cate that the group pullout capacity is a function of the horizontal s pacing between anchors and that the exterior anchors in a closely spac ed group carry the greatest proportion of the load at impending failur e. Empirical equations were developed to predict the pullout capacity of groups of anchors.