The use of wood in the construction of mid- and high-rise buildings is proving to be a competitive alternative to steel and concrete. However, like any other building material and system, wood systems must comply with the rules of building codes and thereby ensure users’ comfort with respect to sound transmission and building vibration.
This session on acoustic and vibration performance will be an opportunity to review recent advances in these fields and share views and experiences with international experts in the field.
Discussions will inevitably take place on how to translate research findings into effective, sustainable technical solutions.
Moderator : Jean-Luc Kouyoumji
Vibration Control for Buildings
Speaker: Victor Salcedo, GERB Vibration Control Systems, USA
Advances in the use of wood in building construction will also require them to perform and meet the stringent demands of structural engineers and their discerning occupants. Typically, vibration isolation requirements are well-known for sensitive receptors such as hospitals, labs and recording studios. Increasingly offices and residential buildings need special consideration to isolate them from a wide range of sources from rail transit to shipping vessel horns in harbors. Additionally, supplemental damping may be required to reduce footfall induced vibration of interior spaces and even to cope with wind induced sway.
The presentation will cover the use of elastic elements for base isolation and Tuned Mass Dampers (TMDs) to add supplemental damping. Examples of entire buildings on springs will be shown as well as TMD use in office floors, monumental stairs, pedestrian bridges and tall/slender steel and concrete buildings. Tuned Mass Dampers ranging from 500 kg to 600 T will also be shown.
Vibration of wood building
Speaker: Pierre Landel, RISE, Sweden
Wind-induced vibrations are becoming the governing serviceability criteria when designing taller timber structures. Adding mass, stiffness, damping, or combinations of them are possible solutions to reducing the sway of tall buildings. Density and stiffness values of wood material are well known but the dynamical properties—the natural frequencies, damping, mode shapes, and modal masses—of large timber structures are hard to predict in general and the damping is most uncertain. The physical process of energy dissipation in timber structures has mainly been studied for seismic load histories.
Vibrational tests of components and the assembled structure play an important role in calibrating numerical models. Such a model is then useful in predicting the structural behaviour and to identify the parameters that influence the sway of the building the most. Results from vibrational tests on, and finite element models of, a large glulam truss for a 6-storey building will be presented. Furthermore, an overview will be given of the ongoing research project Dyna-TTB, in which several of the tallest timber buildings in Europe are studied.
Authors / Co-owners:
- Pierre Landel, RISE Research Institutes of Sweden and Linnaeus University (the Speaker)
- Andreas Linderholt, Linnaeus University
- Marie Johansson, RISE Research Institutes of Sweden
Monitoring and assessing dynamic properties of tall wood building
Speaker: Samuel Cuerrier-Auclair, FPInnovations, Canada
Due to the lightweight nature of wood construction, wind excitation induces vibration with a larger amplitude than in buildings constructed with heavier materials such as steel and concrete. The lack of data on the dynamic performance of wood buildings, such as natural frequencies, damping ratios, and the responses to wind excitation is a challenge to wind-induced vibration-controlled design. To bridge the knowledge gap, five different wood buildings recently constructed in Canada, varying between 6 and 18 storeys, were measured to obtain their natural frequencies and damping ratios using ambient-vibration tests (AVT) and the operational-modal-analysis (OMA) technique before and after completion. It was found that the construction details significantly affected the wood building vibration performance under wind excitation. Buildings with concrete shear walls seem to have higher natural frequencies compared to an all-wood building of similar height. However it is still possible to achieve high frequencies with all-wood buildings using a high performance Lateral Load Resisting System (LLRS).
Victor H. Salcedo is the President of GERB Vibration Control Systems, Inc. located in the greater Chicago area (U.S.). He has served GERB for 18 years and has worked as project lead on many remarkable structures, including 10 skyscrapers with Tuned Mass Dampers up to 700 tons. Mr. Salcedo is an active member of several committees, including the ASME-subcommittee on the Qualification of Dynamic Restraints, the Forging Industry Association Plant Engineering Committee and more recently joined the CTBUH Chicago local steering committee. After attaining a Bachelor of Science degree in Engineering, he specialized with GERB Schwingungsisolierungen GmbH & Co. Kg. in Berlin, Germany in the spring support of machinery and structures, and specialty foundation design. He has contributed to conference papers and publications such as the CTBUH’s Damping Technologies for Tall Buildings.
In 2005 Pierre Landel completed a Mastère in wood structural design from CHEC (Centre des hautes Etudes de la Construction), France and also has a Master degree in mechanical engineering from ENSAM École nationale supérieure d’arts et métiers), France (2004). He was a structural engineer and project manager designing and building CLT projects at Fristad Bygg, Sweden from 2005 to 2014; that year he became a Researcher/PhD candidate at RISE, focusing on wood building technology.
Samuel Auclair completed his Master’s Degree in Civil Engineering on the study of wood-concrete floors in 2015 at Université Laval, where he was honoured for his master’s thesis. He has also submitted a patent for an innovative connector for wood-concrete floors. He now works as a researcher on the structural and serviceability performance of wooden buildings at FPInnovations, where his main research topics are design methods for wood-concrete floors, CLT shear walls, floor vibration and in situ tests on acoustic and vibrational performance of high-rise buildings. Mr. Auclair is the author of several technical publications and research reports on the structural and serviceability performance of wooden buildings.