Improved Soil-Spring Method for Soil-Structure Interaction — Vertical Excitation

An improved Soil-Spring Method for vertical response analysis is proposed. The Soil-Spring Method belongs to the sub structuring methods of analyses for seismic soil-structure interaction. As originally developed the method has certain significant limitations. The proposed improvement is essentially iterative where, successively, layering, embedment, soil damping and frequency-dependent effects are introduced and adjusted until acceptable convergence is achieved. Additionally, input motion for embedded structures is specified using a simple procedure. The methodology is applied to the Lotung 1/4-scale containment model for three recorded earthquakes. The comparisons of the response results with the recorded data and with results obtained using state-of-the-art methods definitely establishes the improved Soil-Spring Method for seismic soil structure interaction as an analysis tool at least comparable to the more sophisticated methods