Caractérisation de l'effet des composants non structuraux sur les propriétés dynamiques des bâtiments

Abstract

Building construction codes need to consider the effect of non-structural components (NSC) on the dynamic properties of the structure. This project aims to assess the effect of these components on the dynamic properties of buildings in the elastic linear range using ambient vibration measurements (AVM) and finite element models. Two buildings located in Montreal were studied. One is an irregular six-storey building on the campus of the École de technologie supérieure (ÉTS) Its lateral load resisting system (LLRS) consists of reinforced concrete (RC) shear walls, rigid RC cores and steel braces. The other one is a rectangular eight-storey building located next to the ÉTS campus. Its LLRS consists of RC shear walls and rigid cores at the ground level and cross-laminated timber (CLT) shear walls and rigid cores at the upper floors. AVM were recorded at multiple floor levels and at different stages of construction: when buildings were composed of structural components only (bare-frame), before adding real estate in the first building (full-frame without interior layout) and once they were completed (full-frame). Then, a pre-processing (MATLAB®) and a modal analysis (ARTeMIS Extractor®) were carried out in order to extract modal parameters (fundamental periods and mode shapes). In the modal analysis, two techniques were used to obtain these parameters: Enhanced Frequency Domain Decomposition (EFDD) and Frequency Domain Decomposition (FDD). By comparing all these periods, it occurs that NSC (partitions, facades, masonry walls, curtain walls and secondary beams) play an important role on modal parameters. However, it is not enough to estimate their contributions in terms of stiffness and mass. Each building was modelled using ETABS 2015® structural analysis software. These models were calibrated manually from the fundamental periods and mode shapes obtained by AVM. Then, it becomes possible to estimate the effect of NSC (infill walls, curtain walls, facades, partitions, etc.) in terms of stiffness and mass, on the dynamic properties of the buildings. The contribution of this project is to estimate the impact of NSC and to illustrate their importance for the evaluation of the dynamic properties of the structures studied. Moreover, we would have to consider the possibility of taking into account the NSC when calculating the fundamental period of a building in the National Building Code of Canada (NBCC). This project reveals that the period of these buildings is overestimated by the equations recommended by the NBCC; furthermore, it also shows that the NSC increases the stiffness of the studied buildings (20.7% extra stiffness for masonry walls, 10.2% for curtain walls, 34.1% for partitions and 10.2% for facades).

Date	10 Jan 2018
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Rola Assi (Supervisor) & Marie-José Nollet (Co-supervisor)