High-strength steel deep H-shaped and box columns under proposed near-fault and post-earthquake loadings
Journal
Thin-Walled Structures
Journal Volume
172
Date Issued
2022
Author(s)
Abstract
This paper presents the seismic evaluation of high-strength steel first-story columns in a seven-story dual system, composed of a special moment-resisting frame (SMRF) and buckling-restrained braced frame (BRBF), in near-fault and post near-fault earthquakes. Nonlinear time history analyses were conducted on the frame to develop loading protocols that represent seismic demands on the first-story columns in the dual system. The proposed near-fault displacement protocol has a large displacement pulse from -2 to +4% drift, followed by small displacement cycles oscillated at a residual drift of 2.5%. The proposed far-field displacement protocol is an increasingly cyclic displacement protocol with one cycle after a drift of 2%. Two built-up H-shaped column specimens (HC-20-B and HC-20-C) and two built-up box column specimens (HBC-40-B and HBC-40-C), representing the first-story columns in the dual system, are tested under constant axial force (0.2Py or 0.4Py) and lateral drifts based on the proposed loading protocols. These specimens that satisfy the compactness requirement of highly ductile members in AISC 341-16 (2016) show acceptable seismic performance under the near-fault earthquake loading. However, the flexural strength of HC specimens decreases with increasing drift, and that of HBC specimens increases without strength degradation. The HBC specimens can perform well in the subsequent near-fault or far-fielding earthquake loading, which is not the case for the HC specimens due to significant local buckling. The NIST (2017) backbone curve reasonably predicts the test envelope of the HC specimens, but significantly underestimates the test envelope of the HBC specimens. ? 2022 Elsevier Ltd
Subjects
BRBF
H-shaped column
Hollow box column
Near-fault earthquake loading test
Nonlinear time history analysis
Earthquakes
Faulting
High strength steel
Loads (forces)
Box columns
Buckling restrained braced frames
Earthquake loadings
H-shaped
Loading tests
Near-fault earthquake
Shaped columns
Structural frames
SDGs
Type
journal article