Abstract :
Current methods in the earthquake resistant design of structures does not usually take into account the effect of the size of the foundation with wavelength interference. This is a very important factor, especially when the construction is massive and the foundation is large. In this paper the effect of the length of the foundation to the response of the structure, when they are subjected to the earthquake travelling surface waves, has been investigated. The results show that a large foundation filters out the high frequency components of the ground motion and reduces its a amplitudes. This in turn will change the input motion to the other stories of the structure.
