This study summarizes the results of 2 static helical anchor uplift tests and 8 cyclic tests in very loose, hydraulically placed sand. Soil strength was characterized using triaxial tests, as well as cone penetration tests. Anchor diameters of 152 mm and 254 mm were tested statically and cyclically. Duration of cyclic loading varied between 600 and 45,000 cycles to assess accumulation of displacements, and transition to cyclic failure. Both one-way (no compression) and two-way loading (involving both compression and tension) cyclic tests were performed, indicating greater accumulation of displacements in two-way tests. Modelling the accumulation of displacement during cycling matched test results well to a displacement of approximately 0.1 to 0.3D, at which point the rate of increase in displacement increased. Cyclic stability diagrams are developed using the presented accumulation of displacements based framework.
J. T. Newgard, J. A. Schneider, J. S. McCartney and D. J. Thompson
Keywords: capacity, cyclic, long term loading, helical anchors
Publisher: DFI