The following topics in the field of seismic analysis and design of mid-rise (5- and 6-storey) wood-frame buildings are included in this paper: Determination of the building period, linear dynamic analysis of wood-frame structures, deflections of stacked multi-storey shearwalls, diaphragm classification, capacity-based design for woodframe...
Cross-laminated timber (CLT) products are gaining popularity in the North American market and are being used in midrise wood buildings, in particular, in shearwall applications. Shearwalls provide resistance to lateral loads such as wind and earthquake loads, and therefore it is important to gain a better understanding of the behavior of CLT shearwall systems during earthquake events. This paper is focused on the seismic performance of connections between CLT shearwall panels and the foundation. CLT panels are very stiff and energy dissipation is accomplished by the connections. A literature review on previous research work related to damage prediction and assessment for wood frame structures was performed. Furthermore, a test program was conducted to investigate the performance of CLT connections subjected to simulated earthquake loads. Two different brackets in combination with five types of fasteners were tested under monotonic and cyclic loading protocols. In total, 98 connection tests were conducted and the monotonic load-displacement curves and hysteretic loops were obtained. In this paper, an energy-based cumulative damage assessment model was calibrated with the CLT connection test data. Finally, a correlation between the damage index and physical damage is provided.
Wood-frame is the most common construction type for residential buildings in North America. However, there is a limit to the height of the building using a traditional wood-frame structure. Cross-laminated timber (CLT) provides possible solutions to mid-...
Nail-Laminated Timber (NLT) and box beam are efficient and economical engineered wood products. Although NLT has been used in North America for more than a century, only in recent years it has gained renewed interests as they have been seen as the most economical panel products used in mass timber buildings. Box beams, on the other hand, are lightweight and generally possess higher strength and stiffness than comparable-sized solid timber and are more efficient than solid timber large spans and loads.
In this report, existing design provisions and their limitations for the design and construction of NLT in box beam in Canadian standards are reviewed. For NLT, there is a general lack of information related to manufacturing, design and construction to ensure consistent manufacturing and installation practices. Therefore, it is difficult to research and document with confidence the full range of performance that can be achieved with NLT. It is therefore recommended that a North American product standard and design information on structural performance, floor vibration, fire resistance, acoustic performance, and construction risk mitigation measures (e.g. moisture and fire) be developed.
In CSA 086, design methods are limited to box beams with flanges and webs bonded with glue. As the flanges and webs of a box beam can be assembled by either glue or mechanical fasteners, it is recommended that design provisions for box beam with mechanical joints be also developed. With the information in Eurocode 5 and relevant supporting research papers, it is ready to be implemented.
A survey was conducted under the "Renessaince in Wood Construction" project that was funded by Natural Resources Canada (NRCan) under the Transformative Technologies Program to see information about numerical modelling on mass timber buildings. A questionnaire was sent to designers and researchers covering different performance attributes. The compiled information includes the available software packages and resources of empirical equations that are used by the designers and researchers for predicting the structural, fire, acoustic, and building envelope (energy and durability) performance of mass timber buildings, and the challenges that they are facing in using those tools. This report summarizes the input obtained from practicing designers and researchers who responded to this survey.
Building tall in wood is not a new phenomenon. In fact, Canada has a history of constructing tall wood buildings out of heavy timber and brick elements, reaching up to nine storeys. In the early 20th century, with the increase in reinforced concrete and structural steel research and construction, and with growing concerns over fire and durability, the structural use of wood fell out of common use in tall buildings. This trend is beginning to reverse, however. In the last few decades, the world has seen a resurgence of mass timber products and systems that are paving the way for tall wood buildings. This triggered an initiative by Natural Resources Canada (NRCan) to support tall wood building demonstration projects to enhance Canada’s position as a global leader in wood building construction, by showcasing the application and performance of advanced wood technologies. The Technical Guide for the Design and Construction of Tall Wood Buildings in Canada has been prepared to assist architects, engineers, code consultants, developers, building owners, and Authorities Having Jurisdiction (AHJ) in understanding the unique issues to be addressed when developing and constructing tall wood buildings.