Dynamic Responses of a Structure with Periodic Foundations

The dynamic responses of a structure with different foundations, including the so-called periodic foundation, are studied. Based on the calculation and optimization regarding the band of frequency gap of a periodic structure, a new kind of periodic isolated foundation is designed. To test the validity of this periodic isolated foundation, the dynamic responses of a seven-storey frame structure with three different foundations are conducted and compared. The analysis assumes that seismic wave input is from the arbitrary direction. This investigation shows that the seismic waves cannot propagate in the periodic foundation without being attenuated when the frequencies of the seismic wave fall within the band of frequency gap of the foundation. Thus, the dynamic responses of the supported structure will be greatly reduced. The investigation supports this new and effective method to block seismic waves for structures in civil engineering. DOI: 10.1061/(ASCE)EM.1943-7889.0000383. (C) 2012 American Society of Civil Engineers.