Estimation of dynamic impedance of the soil-pile-slab and soil-pile-mattress-slab systems

A 3D finite-element model for the dynamic analysis of soil-pile-slab is presented, with the soil-pile-mattress-slab interaction included in studying the dynamic behavior of the rigid-pile-reinforced soils. The soil, piles, and mattress are represented as continuum solids, and the slab is represented by structural plate elements. Quiet boundaries are placed at the boundaries of the model to avoid wave reflection. The formulation is based on the sub-structure method. Different geometric configurations are studied in terms of dynamic impedance. The numerical results are presented to show the influence of the mattress stiffness and the pile-soil contact conditions on the dynamic response of the foundation system. The horizontal and vertical impedances of the pile foundations are presented with the results compared with those available in previous studies.