Seismic collapse risk of precast industrial buildings with strong connections

Abstract

SUMMARYA systematic seismic risk study has been performed on some typical precast industrial buildings that consists of assemblages of cantilever columns with high shear-span ratios connected to an essentially rigid roof system with strong pinned connections. These buildings were designed according to the requirements of Eurocode 8. The numerical models and procedures were modified in order to address the particular characteristics of the analyzed system. They were also verified by pseudo-dynamic and cyclic tests of full-scale large buildings. The intensity measure (IM)-based solution strategy described in the PEER methodology was used to estimate the seismic collapse risk in terms of peak ground acceleration capacity and the probability of exceeding the global collapse limit state. The effect of the uncertainty in the model parameters on the dispersion of collapse capacity was investigated in depth. Reasonable seismic safety (as proposed by the Joint Committee on Structural Safety) was demonstrated for all the regular single-storey precast industrial buildings addressed in this study. However, if the flexural strength required by EC8 was exactly matched, and the additional strength, which results from minimum longitudinal reinforcement, was disregarded as well as large dispersion in records was considered, the seismic risk might in some cases exceed the acceptable limits.

Seismic Response of Precast Industrial Buildings

“…It should be noted, however, that even this very large structure had still smaller spans (mass) compared to those in real structures. -Therefore a systematic numerical study was done showing good response and acceptable risk for a whole set of realistic one-storey structures used in practice (Kramar et al 2010a). -Extremely large top displacements (8 % drift or 40 cm) were recorded at the ultimate stage.…”

“…The study was done in two phases. First a systematic study of single-storey buildings with strong connections (assuming that the proper capacity design procedure was applied) was done (Kramar et al 2010a). Then the study was extended to multi-storey structures with strong and weak connections (Fischinger et al 2012b).…”

“…Record-to-record variability was considered by means of 50 accelerograms generated to simulate the seismic action according to EC8. The hazard function was derived from the design acceleration values for return periods of 475 (0.25 g), 1,000 (0.3 g) and 10,000 years (0.55 g) for the area of Ljubljana (Kramar 2008;Kramar et al 2010a).…”

“…Reference value (5 % percentile of PGA C ) was compared to the design acceleration of 0.25 g. Probability of collapse in 50 years for the area of Ljubljana (H LS,50 ) was considered. While details are given in Kramar et al (2010a), the results are summarised in Figs. 4.45 and 4.46.…”

Cyclic shear tests on RC precast beam-to-column connections retrofitted with a three-hinged steel device

“…2014b), the inadequate seismic response of these structures was mostly caused by the failure of the 35 connection systems between structural elements and structural and nonstructural components. 36 Indeed, even if an acceptable seismic safety is proved for precast structures when they are provided 37 with well-designed dowel connections (Kramar et al 2010), in many structures the connections 38…”