Moein Rezaei Balouchi - MS Student, Dept. of Civil Eng., Faculty of Eng., University of Guilan, P.O. Box ۳۷۵۶,
Reza Saleh Jalali - Assistant Professor,

The impact force response spectrum between two adjacent linear structures excited by faultnormal pulse and fault-parallel displacement with different magnitudes has been considered. Bothstructures have been modelled by single-degree-of-freedom systems and pounding has been simulatedby the non-linear viscoelastic model. The system of coupled equations of motion of the model has been solved by the fourth-order runge-kutta method. The results of the study indicate that thepeak pounding force between adjacent structures induced by fault-normal pulse is many times larger than that induced by fault-parallel displacement. Because of high velocity of the fault motion and under fault-normal pulse with magnitudes M=5, 6, and 7 the gap size of 15cm, 90cm, and 2.25m are necessary, respectively, to avoid collisions for all considered combinations of the structural periods. Under fault-parallel displacement with magnitudes M=5, 6, and 7 the separation gap of 5.5cm, 31cm, and 97cm are necessary, respectively, to prevent pounding

Pounding force, Response spectrum, near-fault earthquake, Forward directivity,Fling-step