A study was performed to determine the feasibility of an outdoor test facility for building envelope materials and components in Vancouver. Test facilities are useful for real-time, real-weather performance assessment of construction materials and assemblies. There are several such facilities in use around the world but none in a climate comparable to that of coastal British Columbia. The feasibility study included a review of existing similar facilities, determination of criteria for a successful Vancouver facility, investigation into research grant opportunities for funding the facility's construction, development of a conceptual design for the facility and its experimental capabilities in order to determine a cost target for fundraising, sampling of a pool of potential paying users of the facility, identification of possible sites and project custodians, and development of a project development plan. The study indicated that the concept for a Vancouver test facility is viable enough to warrant movement into the next phase of project development: handover to a project development team and initiation of fundraising.
The objective of this report is to assist those not fully informed in wood moisture measurement technology and, in addition, to provide general guidance with respect to measuring moisture content in field conditions. Field measurements are more variable and complex than measurements in controlled laboratory or industrial conditions, and as a result there are no established practices addressing all aspects of this methodology. This report is not intended to conflict with methods or techniques used by the wood products industry.
This report of the research project "Improved prediction of seismic resistance of Part 9 Houses" under the CMHC External Research Program consists of a review and assessment of analysis methods; numerical evaluation of current seismic design requirements in Canada; and new formulations for seismic design of conventional wood-frame construction in Canada.
The relative performance of three mechanics-based methods is ascertained by comparing the test data of lateral capacities of partially restrained wall specimens having window openings with the predicted results from three calculation methods: Method 1 by Ni and Karacabeyli (2000, 2002) is the simplest to use and gave the most conservative results; Method 2 by Källsner et al., (2001, 2002) is less conservative but more complicated to apply to practical problems, and Method 3 by Källsner and Gurhammar (2005, 2006) gives non-conservative results. The suitability of other methods of analysis, (e.g. SAWS, Drain2D-X) was also examined. Method 1 was chosen as the principal analysis tool for this investigation.
The adequacy of the seismic provisions of the CWC 2004 Design Guide and of the proposals for Part 9 of the 2010 NBCC are assessed by the seismic design methods specified in Part 4 of the 2005 NBCC and utilizing the analysis Method 1. Two building types were used: a square building of 15.0 x 15.0 m plan and a rectangular one of 4.8 x 15.0 m, each of 1, 2 and 3 storeys height. The analysis indicates that neither the current CWC Guide nor the proposals for the 2010 NBCC Part 9 meet the seismic requirements of Part 4 of the 2005 NBCC for the higher seismic zones. The discrepancies are particularly pronounced for the shorter side of the rectangular buildings.
It must be noted that the buildings studied in this investigation represented worst case scenarios. In reality, wood-frame houses would generally contain more walls than the minimum wall lengths required by the CWC Guide and the proposed NBCC 2010, and thus would possess larger lateral resistance.
Following the numerical results of a parametric study of different wall constructions, two new approaches for the seismic provisions of conventional wood-frame construction in Canada are presented, an area-based method, and a method based on percentages of braced wall lengths. Both methods conform substantially to the seismic requirements of Part 4 of the 2005 NBCC.
For heavy construction the provisions for 1 and 2 storey buildings give reasonable agreement with those for 2 and 3 storeys of light construction.
Additional parameter studies should be carried out for irregular buildings, for heavy wall cladding such as stucco and masonry, and for minimum size of braced wall panels.
This Interim Report of the research project "Improved prediction of seismic resistance of Part 9 Houses" under the CMHC External Research Program presents a detailed literature review of research relevant to lateral resistance of conventional wood-frame construction and an assessment of three mechanics-based methods for calculating lateral capacity.
The relative performance of the three mechanics-based methods is ascertained by comparing the test data of lateral capacities of partially restrained wall specimens having window openings with the predicted results from the calculation methods. Method 1 by Ni and Karacabeyli (2000, 2002) is the simplest to use and gave the most conservative results; Method 2 by Källsner et al., (2001, 2002) is less conservative but more complicated, and Method 3 by Källsner and Gurhammar (2005, 2006) gives non-conservative results.
In the next phase of the project, these mechanics-based methods will be further calibrated against pertinent shake table results from the recent UBC "Earthquake 99" project and from the Forintek – Tongji University tests of conventional wood-frame construction. They will then be employed in the determination of the seismic response of houses as prescribed by the seismic part of the Engineering Guide for Wood Frame Construction published by the Canadian Wood Council.