This paper describes several major challenges facing the designers of tall timber buildings. “Tall” in this context generally means 10 storeys or more, although many of the challenges also apply to timber buildings over 4 or 6 storeys, becoming more severe as the buildings get taller...
Project contact is Christian Dagenais at Université Laval
The National Building Code of Canada (NBCC, NRC 2015) proposes equations to limit acceleration at the top of a tall building. These equations were developed and validated on several buildings designed between 1975 and 2000. The buildings built during these years are made of concrete or steel. It is therefore not certain that the NBCC equations can be applied for tall wooden buildings; wood being a lighter material than concrete and steel. In this project, the PhD candidate will study the impact of lateral load resistance systems and fastening systems used in timber framing on natural frequency and damping as well as its response due to wind loads. The influence of non-structural elements will also be studied. Two high-rise wooden buildings (Origine, 13 floors in Quebec City and Arbora, 8 floors in Montreal) are currently being instrumented to obtain information on the dynamic behavior of the structure. The measurements taken on these two buildings will be used, among other things, to validate theoretical models developed in the context of the doctorate.
It is not surprising to see a rapid growth in the demand for mid- to high-rise buildings. Traditionally, these types of buildings have been dominated by steel and concrete. This trend creates a great opportunity for wood to expand its traditional single and low-rise multi-family building market to the growing mid- to high-rise building market. The significance and importance of wood construction to environmental conservation and the Canadian economy has been recognized by governments, the building industry, architects, design engineers, builders and clients. It is expected that more and more tall wood frame buildings of 6- to 8-storeys (or taller) will be constructed in Canada. Before we can push for use of wood in such applications, however, several barriers to wood success in its traditional and potential market places have to be removed. Lack of knowledge of the dynamic properties of mid- to high-rise wood and hybrid wood buildings and their responses to wind, and absence of current guidelines for wind vibration design of mid- to high-rise wood and hybrid wood buildings are examples of such barriers.
Cross laminated timber (CLT) has been rapidly developed and utilized for multi-rise constructions in recent years, even high-rise CLT buildings with 40 stories have been proposed and designed. A use of unbonded post-tensioning (PT) steel bars through ove...
Advancement in engineered wood products altered the existing building height limitations and enhanced wooden structural members that are available on the market. These coupled with the need for a sustainable and green solution to address the ever-growing urbanization demand, avails wood as possible candidate for primary structural material in the construction industry. To this end, several researches carried out in the past decade to come up with sound structural solutions using a timber based structural system. Green and Karsh (2012) introduced the FFTT system; Tesfamariam et al. (2015) developed force-based design guideline for steel infilled with CLT shear walls, and SOM (2013) introduced the concrete jointed mass timber hybrid structural concepts. In this research, the basic structural concepts proposed by SOM (2013) is adopted. The objective of this research is to develop a wind and earthquake design guideline for concrete jointed tall mass timber buildings in scope from 10- to 40-storey office or residential buildings. The specific objective of this research is as follow:
Wind serviceability design guideline for hybrid mass-timber structures.
Calibration of design wind load factors for the serviceability wind design of hybrid tall mass timber structures.
Guidelines to perform probabilistic modeling, reliability assessment, and wind load factor calibration.
Overstrength related modification factor Ro and ductility related modification factor Rd for future implementation in the NBCC.
Force-based design guideline following the capacity based design principles.