The influence of cyclic lateral loads of various frequencies on a laterally loaded pile embedded in an unsaturated soil

In this work, to evaluate the behavior of a single pile model under the effect of matric suction, it was embedded in soil with various saturation levels and subjected to a series of two-way lateral cyclic loading tests with different frequencies. By decreasing the water table to three distinct stages, three different suction zones were created in the partially saturated soil. The “soil-water characteristic curve” (SWCC) is the relationship between the gravity water content and matric suction. The pile model used is aluminum of 600 mm in length and 16 mm diameter embedded in ( dry, unsaturated and saturated ) sandy soil for comparisons. The pile model is under lateral cyclic loading (40N for 40 cycles) of various frequency values (0.05, 0.1 and 0.2 Hz). The study’s findings demonstrate that the presence of matric suction greatly affected the pile model’s displacement and bending moment. In comparison to saturated circumstances for the same relative density, there was a reduction in bending moments and lateral displacements of 12%, 23%, and 32% for the first, second, and third lowering of the water table, respectively. Additionally, under all saturation conditions, the increase in cyclic lateral loading frequency resulted in a 25% increase in displacement and bending moment.