This book describes recent studies of soil behaviour in strong ground motion - one of the most important and problematic issues in engineering seismology. Destructive earthquakes worldwide show us the damage of structures located on soil foundations; therefore, reliable and adequate estimations of in situ soil behaviour during strong motion are needed. The effects of soil response proved to be more complicated and diverse than we thought previously. Additionally to well-known amplification of seismic waves in near-surface softer layers, resonant phenomena and nonlinearity of soil...