Improvement of progressive collapse resistance potential of semi-rigid jointed steel frames through bracings

Abstract

Progressive collapse studies of both unbraced and braced semi-rigid jointed steel frames have been carried out to evaluate the contribution of bracings in improving progressive collapse resistance potential. Numerical models of 10-story frames with different types of semi-rigid connections have been developed using SAP2000. Progressive collapse potential of semi-rigid frames is first investigated without bracings. Bracings are then included in a systematic manner, and response of the braced frame is compared with that of unbraced frame to evaluate the contribution of bracings. Two different arrangements of bracings, that is, bay-wise and floor-wise arrangements, are considered to find out a preferred arrangement of bracings. Parametric studies include eight column removal conditions at center and corner locations of different floors. Development of catenary action has also been considered as it gives additional resistance, especially to braced frame. Apart from nonlinear static analysis, effects of bracings are evaluated also through nonlinear dynamic analysis and the responses of the frames in nonlinear dynamic analysis are compared with those of nonlinear static analysis. From the study, it is found that provision of bracings significantly improves the progressive collapse resistance potential of the semi-rigid frames under different column removal conditions. Floor-wise arrangement of bracings is much effective as compared to bay-wise arrangement.

Combined Sensor Method for Measuring Torsional Vibration and Anti-Collapse Performance of Steel Frame under Strong Earthquake

“…is the peak stress of the stress-strain ratio, is the strain force corresponding to the peak stress, and are the yield strength and compressive strength of the steel pipe in the core area, and are the cross-sectional areas in the steel pipe and concrete of the core area [28].…”

Analysis of the Progressive Collapse Resistance Mechanism of an RC Frame Structure with an L-Shaped Plane

“…Adding a new structural member to provide additional alternate load paths is a classic approach for strengthening structural systems against progressive collapse. For example, Bandyopadhyay et al [8] studied the progressive collapse of both unbraced and braced semi-rigid jointed steel frames in order to evaluate the contribution of bracing to improving the progressive collapse resistance. Yu et al [9] proposed a steel bracing design method based on incremental dynamic analysis (IDA) in order to explore the influence of steel bracing on RC frame resistance to progressive collapse.…”