Permanent strains of piles in sand due to cyclic lateral loads

The strain superposition concept, proposed for ballast study, is applied he re to evaluate strain accumulation for laterally loaded piles in sand. It i s shown that the soil properties, types of pile installation, cyclic loadin g types, pile embedded length, and pile/soil relative stiffness ratio are i mportant factors that influence the pile behavior under mixed lateral loads . These factors are quantified by means of a degradation factor, t, which i s derived from the results of 20 full-scale pile load tests and then verifi ed using 6 additional full-scale pile load tests.