Investigation of pullout load capacity for helical anchors subjected to inclined loading conditions using coupled Eulerian-Lagrangian analyses

The pullout load carrying behavior of helical anchors for inclined loading conditions was investigated based on the coupled Eulerian-Lagrangian (CEL) analyses. Various types of helical anchors, specified as Types 1 to 6, were adopted in the analyses. Types 1, 2 and 3 represent those with one, two, and three equal-diameter helical plates and Type 4 was a helical anchor type with two helical plates of different diameters. Types 5 and 6 were both with three helical plates of different diameters in opposite diameter configurations. Inclined loading conditions affected the pullout capacity (Q _u ) of helical anchors producing lower Q _u with increasing load inclination. The patterns of the Q _u decrease with increasing load inclination were similar for all helical anchor types considered in this study. The values of Q _u were approximately similar up to θ = 60° and then decreased continually with furthering increasing θ. Q _u was lowest at θ = 90°. The top-down increasing diameter configuration of helical plates was more efficient than the bottom-up increasing diameter configuration. A normalized load capacity relationship was proposed, which can be used to evaluate Q _u for inclined loading conditions. The pullout behavior of helical anchors was governed by helical plates with marked effects of helical plate configuration, which was however less pronounced with increasing θ.