Diaphragm Flexibility
Diaphragms are essential to transfer lateral forces in the plane of the diaphragms to supporting shear walls underneath. As the distribution of lateral force to shear walls is dependent on the relative stiffness/flexibility of diaphragm to the shear walls, it is critical to know the stiffness of both diaphragm and shear walls, so that appropriate lateral force applied on shear walls can be assigned. In design, diaphragms can be treated as flexible, rigid or semi-rigid. For a diaphragm that is designated as flexible, the in-plane forces can be assumed to be distributed to the shear walls according to the tributary areas associated with each shear wall. For a diaphragm that is designated as rigid, the loads are assumed to be distributed according to the relative stiffness of the shear walls, with consideration of additional shear force due to torsion for seismic design. In reality, diaphragm is neither purely flexible nor completely rigid, and is more realistically to be treated as semi-rigid. In this case, computer analysis using either plate or diagonal strut elements can be used and the load deflection properties of the diaphragm will result in force distribution somewhere between the flexible and rigid models. However, alternatively envelope approach which takes the highest forces from rigid and flexible assumptions can be used as a conservative estimation in lieu of computer analysis
A Mechanics-Based Approach for Determining Deflections of Stacked Multi-Storey Wood-Based Shearwalls
The 2009 edition of CSA Standard O86, Engineering Design in Wood (CSA 2009), provides an equation for determining the deflection of shear walls. It is important to note that this equation only works for a single-storey shear wall with load applied at the top of the wall. While the equation captures the shear and flexural deformations of the shear wall, it does not account for moment at the top of the wall and the cumulative effect due to rotation at the bottom of the wall, which would be expected in a multi-storey structure. In this fact sheet, a mechanics-based method for calculating deflection of a multi-storey wood-based shear wall is presented.
Design of Stacked Multi-Storey Wood Shearwalls Using A Mechanics Based Approach
This document is a Design example of Stacked Multi-Storey Wood Shearwalls Using A Mechanics Based Approach. It shows a floor plan and elevation along with the preliminary shear wall locations for a six=storey wood-frame building. It is assumed some preliminary calculations have been provided to determine the approximate length of wall required to resist the lateral seismic loads.
Linear Dynamic Analysis for Wood Based Shear Walls and Podium Structures
With the height limit for combustible construction limited to four stories under the National Building Code of Canada, it was uncommon for designers to perform detailed analysis to determine the stiffness of shear walls, distribution of forces, deflections, and inter-storey drifts. It was only in rare situations where one may have opted to check building deflections. With the recent change in allowable building heights for combustible buildings from four to six storeys under an amendment to the 2006 BC Building Code, it has become even more important that designers consider more sophisticated methods for the analysis and design of wood-based shear walls. As height limits increase, engineers should also be more concerned with the assumptions made in determining the relative stiffness of walls, distribution of forces, deflections, and inter-storey drifts to ensure that a building is properly detailed to meet the minimum Code objectives. Although the use of LDA has not been common practice, the more rigorous analysis, as demonstrated in the APEGBC bulletin on 5- and 6-storey wood-frame residential building projects (APEGBC 2011), could be considered the next step which allows one to perform an LDA. This fact sheet provides a method to assist designers who may want to consider an LDA for analyzing wood-frame structures. It is important to note that while LDA may provide useful information as well as streamline the design of wood-frame structures, it most often will not be necessary. However, designers may consider using LDA for the following reasons: Consider the effect of higher mode participation on force distributions and deflections. Better determine building deflections and floor drifts. Allow for three-dimensional modelling. Reduce the minimum Code torsional effect required under the equivalent static design. Better consider the effect of podium structures (vertical changes in RdRo). Compare the stiffness of various shear wall systems where mixed systems are used.
Administration and Training Facility (Alberta Boilers Safety Association)
The new ABSA facility is located in Edmonton’s Research Park (Figure 1), joining 35 other technology companies and agencies. To accommodate staff and increased visitor traffic, the new ABSA facility has 51 parking spaces on the site and another 49 in the parkade below the building. Completed in May 2006, the ABSA facility utilizes glulam beams and columns to achieve the Building Committee’s design objectives for aesthetics, lighting, energy and environment.
Algonquin College Perth Campus
Algonquin College is a major provider of post-secondary education in Eastern Ontario, with campuses in Ottawa, Perth and Pembroke. The Perth Campus is located in the Town of Perth, approximately 65 km west of Ottawa. In keeping with Perth’s historic involvement with the Rideau Canal World Heritage Site, the Perth Campus’ area of excellence is heritage preservation training, which draws students from the local community and from around the world. In 2009, planning began for a new building capable of accommodating more students. During construction of the new building, comprised of the Academic Hall and the Construction Wing (Figure 1), classes continued in an old building that was subsequently demolished. A new outdoor construction pad is located over the footprint of the old building. The new building was ready for classes in September 2011, one year after the start of construction. The town of Perth has a rich history, reflected in the nineteenth-century mills and factory buildings along the Tay River, Victorian storefronts and grand, century-old, timber-frame buildings. The Algonquin College Perth Campus building sought to blend with this fabric through the use of traditional forms, locally sourced materials, and woodframe construction.
B.C. Schools (Crawford Bay Elementary-Secondary & Richmond Christian)
Crawford Bay is a small and remote community on the east shore of Kootenay Lake in the southern interior of British Columbia. A community of about 500 people, it is one of several such communities collectively known as the East Shore communities. Historically, the area has relied heavily on logging for employment but, since the 1960s at least, has also been home to grassroots environmentalists and, more recently, to highly educated exurbanites who form part of a ‘back to the land’ movement. There is also a strong artisan community with a broad range of skills in carving, weaving, ironwork and other arts. The village of Crawford Bay has been home to a one-room school house since 1946, and the need to replace this aging facility provided the impetus for this project. A feasibility study quickly determined that rehabilitation and expansion of the existing building was not cost effective, nor could the existing site readily accommodate a new structure and the required ancillary facilities such as playing fields and parking lots. Accordingly, a new site was selected and design of the new school commenced in 2004.
Community Resource Centre
The Greenfield Community Resource Centre and Elementary School is located in a small, isolated forestry community in Nova Scotia where 16.1 % of employment is provided by the forestry sector. This forestry based community is proud of its local heritage. Indeed, in 1987 it was dubbed the “Forestry Capital of Canada” and to this day has a “Build First with Wood” policy in place for new construction. The Resource Centre, valued at $1.3 million Canadian dollars, was built by a non-profit community group to replace an insufficient and outdated building that was over 60 years old.
Grizzly Paw Brewing Company
In 1996, The Grizzly Paw Brewing Company began brewpub restaurant operations in Canmore, Alberta, at the doorstep of Banff National Park. Since then, the business has attained microbrewery status, and success and growth have led to the need for a brewery building to meet present and future needs for supplying beer and carbonated drinks to Canmore, Banff, Calgary, and other communities across Alberta. The purpose of the new brewery is to augment the capacity of the existing brewpub by a factor of 8 to 10 to meet increasing demand for the Grizzly Paw brands. The new building will also have hospitality space suited to tours and receptions once the brewing facility is running smoothly. The building is located on a one-acre site in a commercial zone at the gateway to Canmore (Figure 1). The brewery was initially designed to be a steel building, but preliminary cost estimates were over-budget. An alternative conceptual design was made based on exposed heavy timber construction. The resulting timber building met all the building science challenges, saved money, and better met the Rocky Mountain architectural design motif of Canmore. It provides a pleasing appearance that will attract additional publicity and be very conducive to guided tours through the brewery.
Richmond Olympic Oval
The Richmond Olympic Oval is the largest structure to be built for the Vancouver 2010 Olympic Winter Games. Designed to accommodate the long track speed-skating events before an audience of more than 8000 spectators, the building features a 6 acre (2.5 hectare) free spanning roof that is a precedent setting example of British Columbia’s and Canada’s advanced wood engineering and prefabrication capabilities. The building is located a short distance from Vancouver’s International Airport in the City of Richmond, where after the Games, it will be transformed into a multi-sports training and recreation facility at the centre of a new residential and commercial neighbourhood. Construction of the project began in 2005, and the building was opened on time and under budget in December 2008.
Slave Lake Government Centre and Library
Located 250 km north of Edmonton, the Town of Slave Lake, Alberta, is home to 7,000 residents and serves as a regional hub for a population of 25,000. It’s economic base includes tourism, oil, gas and forestry industries. The new Slave Lake Government Centre and Library was designed and built to consolidate a number of government services, in outdated facilities, that were distributed throughout the community of Slave Lake. The new building, which is a combination of renovated space and new construction (Figure 1), has streamlined the delivery of public services in Slave Lake and provided a central place where citizens can meet, interact and conduct daily business in one stop.
Full Scale Exterior Wall Test on Nordic CLT System, by the National Research Council
This report describes a full-scale exterior wall fire test conducted on December 16, 2014 on a Nordic cross-laminated timber (CLT) wall system. The test was conducted in accordance with CAN/ULC-S134-13, Standard Method of Fire Test of Exterior Wall Assemblies.
