The Earthquake Engineering Online Archive

Soil structure interaction in different seismic environments

Gomez-Masso, Alberto; Lysmer, John; Chen, Jian-Chu; Seed, H. Bolton

UCB/EERC-79/18, Earthquake Engineering Research Center, University of California, Berkeley, 1979-08, 55 pages (535/G59/1979)

Presented is a plane-strain method for soil-structure interaction analysis in a generalized seismic environment. The method involves the superposition of the free field motions and the interaction motions. The free field is modeled as a horizontally layered viscoelastic medium and the seismic environment may consist of a combination of S, P, and Rayleigh waves. The soil-structure system is modeled with viscoelastic finite elements, transmitting boundaries, viscous boundaries, and a 3-dimensional simulation. Comparative analyses of the same structure are conducted for an input of R waves and for vertically propagating S and P waves in a rock site and a sand site. In the rock site, the R waves produce higher peak horizontal spectral acceleration up to 25% and a significant rocking effect at points away from the center of gravity of the structure. However, the S and P waves show a higher peak vertical spectral acceleration by up to 15% at the center of the structure. In the sand site, a similar horizontal response is obtained, but a higher vertical response is obtained at the center of the structure for S and P waves.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-79-18.pdf (1 MB)