NEHRP Clearinghouse

Statistical Evaluation of Deflection Amplification Factors for Reinforced Concrete Structures.
Hwang, H. H. M.; Jaw, J. W.; Ch'ng, A. L.
National Center for Earthquake Engineering Research, Buffalo, NY.; National Science Foundation, Washington, DC., August 31, 1989, 74 p.
The report presents a statistical evaluation of the deflection amplification factors C(d) for reinforced concrete structures. Twelve multi-degree-of-freedom structural models with various dynamic characteristics are first constructed. Next, ninety synthetic earthquakes are generated from three power spectra representing different soil conditions. Then, the non-linear and corresponding linear time history analyses are performed to produce structural response data. These data are used to derive an empirical formula for the C(d) factor by regression analysis. On the basis of this empirical formula, the C(d) factors for the design of building structures are recommended. From the comparison of the proposed C(d) factors with those specified in the NEHRP Recommended Provisions, it appears that most of the C(d) factors specified in the NEHRP Provisions are too large and consequently the design story drifts of structures are overestimated.
Reliability; Regression analysis; NEHRP Program; Buildings; Earthquake engineering; Earthquake resistant structures; Reinforced concrete; Deflection; Amplification factors; Design; Tables (Data); Seismic risk