Experiment of single screw piles under inclined cyclic pulling loading

The ultimate pullout capacity under inclined dynamic loading is an important measure of the destruction degree of vertical screw piles (anchors) under dynamic actions. Based on the static and dynamic tests on two kinds of model screw piles, the ultimate bearing capacity was researched considering different distance-width ratio of blade (<i>D</i>/<i>W</i>) and preloading ratio. The results compared well with other experimental data available in the literature. This research reveals that <i>D</i>/<i>W</i> might determine the failure model of the piles (anchors), for example <i>D</i>/<i>W</i> = 3.14 or 5; a critical dynamic-static loading ratio (DSLR) existed in the experiments. The critical DSLR was reached under the conditions of 40%~60% preloading (<i>D</i>/<i>W</i> = 3.14) or 20%~40% preloading (<i>D</i>/<i>W</i> = 5), respectively.