Three-Dimensional Seismic Structural Analysis of Letterman Hospital.
Abstract
This report summarizes the results of a three-dimensional seismic analysis of the primary structural elements of Letterman Hospital, Presidio of San Francisco, performed using response spectrum modal analysis procedures. These results are compared with those of a two-dimensional analysis of the hospital performed by Agbabian Associates (AA), E1 Segundo, CA, which used time history modal analysis procedures. Overall agreement between the two analyses was good considering: (1) The difference in analysis methods; (2) The numerous instances where engineering judgment was required to idealize the complex structure and compute the required structural properties; and (3) The assumptions inherent in the computer programs. Both analyses, as compared to the original seismic design forces, provide: (1) More realistic estimates of the dynamic forces the structure may be expected to resist; (2) The influence of the higher modes on the response of the structure; and (3) The actual distribution of the dynamic forces among the structural members. Furthermore, computing the dynamic response of Letterman Hospital using the response spectrum modal analysis method was not significantly more complex than computing the structure's static response when subjected to equivalent lateral loadings.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1976
- Accession Number
- ADA022085
Entities
People
- C. K. Choi
- J. D. Prendergast
Organizations
- Construction Engineering Research Laboratory