NEHRP Clearinghouse

Response of Simple Structural Systems in Traveling Seismic Waves.
Morgan, J. R.; Hall, W. J.; Newmark, N. M.
National Science Foundation, Washington, DC. Engineering and Applied Science., September 1979, 127 p.
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An investigation is undertaken of the possibility of using a traveling seismic wave procedure to study the translational and rotational responses of a building. This project was conducted with a view to assessing current building code procedures and to establish bounds for the interrelationship between torsional and translational response. The theory and procedure for both superposition and coupled reaction models used in the study are described together with results obtained. Three assumptions were made throughout the investigation; (1) only systematic motions over the base were taken into account, (2) only horizontally propagated plane waves with vertical wave fronts of motions were considered, and (3) only rigid foundation systems were considered. Results indicate that, in general, the coupling of translational and rotational response leads to increased scatter in the computed responses obtained and less certainty in the types of trends noted for the superposition model. This study indicates that the five percent building code value for accidental eccentricity appears reasonable. Results clearly indicate the need for instrumentation to obtain a more detailed picture of the translation and rotation experienced by a building during earthquake excitation.
Superposition (Mathematics); Ground motion; Buildings; Building codes; Earthquake engineering; Earthquake resistant structures; Traveling waves; Theses; Earthquakes; Soil structure interactions; Plane waves; Earth movements; Mathematical models; Seismic waves