AN EXPERIMENTAL INVESTIGATION OF THE DYNAMICCHARACTERISTICS OF LOW RISE STEEL STRUCTURES

摘要

This paper describes the experimental investigation of the dynamic properties of low-risesteel structures. These buildings are used for light industrial, commercial, and recreational purposes andare commonly found in Canada. The National Building Code (NBCC) design seismic loads vary with thefundamental period of the structure, where lower forces occur for buildings with longer periods. In thecurrent (1995) and in the proposed 2005 edition of the NBCC, empirical formulas are presented for thecalculation of the fundamental period for seismic load determination. These formulas have been derivedfor multi-storey structures with rigid floor and roof diaphragms, which differ fundamentally from low-risesteel buildings. One of the goals of the research project described herein is to develop an experimentaldatabase, using ambient vibration testing to obtain the key dynamic properties for a large number of lowrisesteel structures. The paper describes the methodology involved in ambient in-situ testing of singlestorey steel buildings. Modal properties obtained from ambient tests as well as a preliminary statisticalanalysis on the processed data are presented. A comparison between the preliminary tests results and theempirical formulas of the current and proposed NBCC seismic provisions is also presented.