Related sections in the International Building Code (IBC) were reviewed regarding use of wood components in non-combustible buildings, and light-frame wood buildings or heavy timber buildings greater than 4-storeys in height.
The highlights of this review are:
a) Fire-retardant-treated (FRT) wood can be used in partitions when the required fire-resistance rating is not more than 2 hours. This includes all types and occupancy groups of Types I and II construction;
b) FRT wood can be used in non-bearing exterior walls in Type I, II, III and IV construction;
c) Wood components can be used in interior walls for Type III and IV construction;
d) Wood components can be used in both interior and exterior walls for Type V construction.
When a sprinkler system is installed according to NFPA 13 , it is possible to build a light-frame wood building or heavy timber building over 4-storeys according to the following provisions:
a) Type IIIA 6-storey light-frame wood buildings using FRT wood for exterior walls for Occupancy group B (Business), H-4, and 5-storey light-frame wood buildings for Occupancy group F-2, H-3, I-1(Institutional), R (Residential), S-2;
b) Type IIIB 5-storey light-frame wood buildings using FRT wood for exterior walls for Occupancy group R;
c) Type IV (HT) 6-storeys timber buildings for Occupancy group B, F-2, H-4 and S-2;
d) Type IV (HT) 5-storeys timber buildings for Occupancy group F-1, H-3, I-1, R, S-1 and U.
This project evaluates the National Building Codes of Canada (NBCC) clauses relevant to fire performance and performance requirements of non-load-bearing wood-frame in-fill walls in concrete/steel hybrid buildings. Related clauses in NBCC are reviewed regarding the use of wood components and non-load bearing wall systems in non-combustible buildings. The highlights of this review are:
§ An exterior non-loadbearing wall assembly with combustible components is allowed in non-combustible construction if:
a) Building height is not more than 3 storeys or has a sprinkler system throughout ;
b) The interior surfaces of the wall assembly are protected by a thermal barrier ; and
c) The wall assembly satisfied the testing criteria for CAN/ULC S134 ;
§ Combustible interior wall finishes, other than foamed plastics, are allowed in non-combustible construction if the thickness is not greater than 25 mm and their flame spread rating (FSR) is not more than 150 ;
§ Combustible insulation, other than foamed plastics, is allowed in non-combustible construction if the flame-spread rating not more than 25 ;
§ Combustible insulation with a FSR not less than 25 and not more than 500 is allowed in exterior and interior walls of non-combustible construction if the building is non-sprinklered and not more than 18 m or sprinklered and protected by a thermal barrier ;
§ There are no obstacles for using wood-frame in-fill wall systems for interior partition walls in hybrid buildings:
a) For non-sprinklered buildings not greater than 3 storeys or a floor area not greater than 600 m2 ;
b) For sprinklered buildings.
§ Non-combustible construction allows combustible elements in partition walls in the following instances:
a) Solid lumber partitions located in a fire compartment area are permitted in a non-sprinklered floor area not greater than 600 m2 with restrictions ;
b) Solid lumber partitions not less than 38 mm thick and partitions that contain wood framing are permitted with restrictions.
§ Combustible cladding can be used under the following circumstances:
a) When a wall assembly with exposing building face is between 10 to 25% tested by CAN/ULC-S134 and complies with Article 188.8.131.52 ;
b) When a wall assembly with exposing building face is between 25 to 50%, is sprinklered throughout, installed on a gypsum board sheathing, and has a FSR not more than 25 (with restrictions) ;
c) When a wall assembly with exposing building face is between 50 to 100%, cladding can be combustible for group A, B, C, D, E, F.
§ When a building is required to be of non-combustible construction, combustible elements are limited to the requirements in Subsection 3.1.5 on non-combustible construction ;
§ When comparing the NBCC with the International Building Code (IBC), the IBC is more in favour of using FRT wood frame in-fill walls with one more storey.
Under this project, a set of guidelines for using fingerjoined lumber for metal plate connected trusses has been prepared. This project is a result of several projects undertaken over the last 10 years on trusses, trusses and fingerjoined lumber, and the development of new structural wood adhesive standards.
The draft guidelines are based on findings from previous Value-to-Wood studies, and on information gathered from truss fabricator interviews and surveys carried out by FPInnovations Industry Advisors of the past year. The guidelines also assume that the fingerjoined lumber is produced to the recently updated National Lumber Grades Authority Special Products Standard (SPS) 4, which was revised to reference the latest edition of the Canadian wood adhesive standard CSA O112.10. While use of this standard permits the fingerjoined lumber industry to use a wider range of structural wood adhesives, it does require that the lumber be marked as “Dry Use Only”.
Given that NLGA SPS 4 is the first standard on commodity structural fingerjoined lumber to have a “Dry Use Only” label, the development of these guidelines is timely. The guidelines will not only help the truss industry and builders to better understand and properly use the product, but it will also help in code acceptance of the NLGA SPS 4 standard.
The study investigated self-reported health effects among 223 tree planters at 13 sites in British Columbia and western Alberta, and measured personal exposure to fertilizer dust, heavy metals, and certain pesticides among a subgroup of 54. The study identified an association between chronic respiratory symptoms (cough, phlegm, and nasal symptoms), nosebleed, and skin irritation, and duration of work with fertilizers among tree planters. Overall, among the 54 individuals examined, measured exposures to heavy metals and dust were low. Pesticide exposure was also low, but residues found on seedlings and skin samples demonstrate a potential route of exposure. Opportunities exist for fairly straightforward improvements to hygiene conditions and dermal protection (i.e., glove) programs that would reduce the risk of exposure.
The Forest Engineering Research Institute of Canada (FERIC) and the B.C. Ministry of Forests’ Resource Tenures and Engineering Branch surveyed users of closed-bottom corrugated-steel embedded culverts to find installations that generally conform to the Fish-stream Crossing Guidebook that was released in 2002 under the Forest Practices Code of British Columbia Act. This report describes seven sites that were visited, and includes the installation procedures and costs for each of the sites.
Results from a three-year research project on the performance of structural systems with glulam riveted connections in non-residential buildings are presented in this report. The emphasis is placed on use of timber rivets in structural systems such as braced frames and moment resisting frames.
Initially a comprehensive literature survey on the topic is given, including the historical development of the fastener and previous research work. This is followed by state-of-the-art information on the static and dynamic behaviour of glulam riveted connections in heavy timber construction. Research results include information on all phases of the project:
· Bending and tension tests to determine the material properties of timber rivets as fasteners;
· Embedment tests of timber rivets in various wood products parallel and perpendicular to grain or strand;
· Quasi-static monotonic compression tests on small riveted connections in four different wood products loaded parallel and perpendicular to grain or strand;
· Quasi-static monotonic and cyclic tests on axially loaded members with riveted connections used in braced timber frames;
· Cyclic tests on portal moment resistant frames with riveted connections in four different wood products;
· An analytical methodology to quantify the dynamic performance of braced frames with timber rivets;
· Force modification factors for braced timber frames with riveted connections according to the NBCC.
· Force modification factors for portal moment resisting frames with riveted connections according to the NBCC;
Results of the study cover riveted connections in four different engineered wood products: Glulam, Laminated Veneer Lumber (LVL), Parallel Strand Lumber (PSL), and Laminated Strand Lumber (LSL). It should be noted that a comparison of the behaviour of riveted connections in different wood-based products was not the objective of the study. Consequently, the material sampling plan included one manufacturer per product.
The study provides relevant information that may be used to produce technical guidelines for design and construction of both types of frames with riveted connections. Such design guidelines and performance characteristics currently exist for structural systems in other construction materials such as steel and concrete, while with exception of wood-frame shear walls, they are virtually nonexistent for other wood–based structural systems.
The Forest Engineering Research Institute of Canada (FERIC) surveyed users of closed-bottom corrugated-steel embedded culverts within British Columbia and visited selected sites. This report presents information about the installations visited, including the installation procedures and costs. This report also provides suggestions for the implementation of future embedded culverts.
The Forest Engineering Research Institute of Canada (FERIC) monitored and documented the installation of a closed-bottom corrugated-steel embedded pipe culvert on a newly built section of forest road near Powell River, B.C. Detailed installation procedures and cost information are presented. Suggestions for implementation of future embedded culverts are given.
Results from the first two years of the research project on the performance of structural systems with glulam riveted connections in non-residential buildings are presented in this report. The emphasis is placed on use of glulam rivets in structural systems such as braced frames and moment resisting frames.
Initially a comprehensive literature survey on the topic is given, including the historical development of the fastener and previous research work. This is followed by state-of-the-art information on the static and dynamic behaviour of glulam riveted connections in heavy timber construction. Research results include information from the following phases of the project:
Bending and tension tests to determine the material properties of glulam rivets as fasteners;
Embedment tests of glulam rivets in various wood products parallel, perpendicular and oblique to grain or strand;
Quasi-static monotonic compression tests on small riveted connections in various wood product loaded parallel and perpendicular to grain or strand;
Quasi-static monotonic and cyclic tests on axially loaded members with riveted connections used in braced timber frames;
Progress on the development of an analytical model to predict the resistance of riveted connections subjected to eccentric loading.
The results of the study cover riveted connections used with four different engineered wood products: Glulam, Laminated Veneer Lumber (LVL), Parallel Strand Lumber (PSL), and Laminated Strand Lumber (LSL). It should be noted that a comparison of the behaviour of riveted connections in different wood-based products was not the objective of the study. Consequently, the material sampling plan included one manufacturer per product.
The study will help provide relevant information that will be used to produce technical guidelines for design and construction of both types of frames with riveted connections. Such design guidelines and performance characteristics currently exist for structural systems in other construction materials such as steel and concrete, while with exception of wood-frame shear walls, they are virtually nonexistent for other wood–based structural systems.
The longitudinal shear capacity of the lumber is one of several ultimate limit states assessments that need to be undertaken when designing a metal plate-connected truss. In most cases, the shear of the lumber is not the controlling parameter when selecting a size, grade, or species of lumber for use in a truss. When it does control, the size of the affected member size is either increased and/or the member is replaced with a member from a species grouping that is assigned higher specified shear strength. Except for some grades of machine-graded lumber, higher shear capacity cannot be obtained by selecting a higher grade of lumber.
In 1996, the Truss Plate Institute of Canada (TPIC) adopted the stiffness method as the basis of truss design in Canada. Along with this new analytical approach were new truss analogues, the most significant being the heel analogue of pitched chord trusses. One of the ramifications of adopting the new TPIC design procedures noted by users of the new procedures was the increased incidence of designs where shear strength dictated the selection of the chord member, but only if the truss were analyzed using the new TPIC procedures.
To better understand this situation and develop a possible solution, a 2-ply pitched chord truss with a girder heel detail was selected for analysis using the girder heel analogues from the 1988 and the 1996 editions of the TPIC “Truss Design Procedures and Specifications for Light Metal Plate Connected Wood Trusses.” These results were then compared to results from the Forintek “Structural Analysis of Trusses” (NSAT) program. Based on the member forces estimated by the NSAT program, a simplified 2-dimensional finite element analysis was carried out on the bottom chord at the girder heel.
The following were observed:
The discrepancy in the computed shear forces between the TPIC-88 and TPIC-96 is confirmed. At the traditional design points (location displaying the highest shear force in the bottom chord), both the TPIC-88 and NSAT analogues gave similar results. Results from the TPIC-96 analogues were typically 18 to 22% higher than the TPIC-88 and NSAT analogue results.
Both the TPIC-88 and TPIC-96 did not report the presence of a high shear force in the bottom chord of the girder heel joint (i.e. a “blind spot”). Only the NSAT model was able to highlight this shear force. Although a more detailed finite element analysis of the bottom chord in the girder heel joint suggests significantly lower shear stresses, the stresses were still found to be higher than that permitted.
The following are recommendations for consideration by the TPIC and the provincial wood truss associations:
The TPIC-96 analogue may be adjusted to give shear force values in the bottom chord that are comparable to that in the TPIC-88 and NSAT models. This is achieved by reducing the modulus of elasticity of the web members by approximately 10%.
Given the general uncertainty in estimating member shear force using truss analogues, the industry should consider whether or not the adjusted analogue is necessary given that significant increases to the specified shear strength of lumber is currently under consideration by the CSA Technical Committee on Engineering. The proposed increases would raise the shear strength of lumber by about 50%.
The high shear stress in the girder heel joint identified by the NSAT analogue, but missed by the TPIC-88 and TPIC-96 analogues should be assessed more closely before considering any remedial action. Alternate combinations of truss pitch and chord sizes may offer a more severe stress condition and thus a more appropriate configuration for developing empirical data is needed for supporting the girder heel joint detail.
The permitted practice of ignoring the “shear due to loads applied near the supports” as described in the CSA O86 and the NDS should be considered carefully by the TPIC to determine whether the intent of the provisions are properly applied in truss applications.
The Forest Engineering Research Institute of Canada (FERIC) monitored and documented the installation of an embedded corrugated-steel pipe culvert as a replacement structure for a perched culvert. Detailed installation procedures and total costs (including planning) for the project are presented. Suggestions for implementation of future embedded culverts are given.
The Forest Engineering Research Institute of Canada (FERIC) monitored and documented the installation of an embedded corrugated-steel pipe culvert as a replacement structure for a temporary concrete-slab bridge. Detailed installation procedures and total costs (including planning) for the project are presented. Suggestions for implementation of future embedded culverts are given.
The key objectives are to assist industry initiatives to enable the structural engineering community to design and construct more economical, effective and innovative non-residential structures utilizing wood-based systems with riveted connections. The project will specifically:
Develop an analytical methodology to quantify the static and dynamic performance of braced frames and moment resisting frames with timber rivets in glulam;
Determine the performance of these structural systems with different configurations of riveted connections in glulam;
Increase the body of knowledge about strength and deformation properties of timber riveted connections in different engineered wood products;
Applying the developed methodology, evaluate the performance of braced frames and moment resistant frames when built with various engineered wood products;
Implement the research findings, in cooperation with the Canadian Wood Council, in national and international building codes and standards.
To determine the extent of heavy metal contamination from galvanised steel poles, the soil around five poles was sampled and analysed. After the steel poles had been in place only two years, zinc levels were elevated around all poles and were above the cleanup guidelines for soils in residential and agricultural for two of the five poles tested.
With the appropriate mainline attachment, chain chokers are a viable alternative to conventional wire rope chokers, particularly for small-scale operations. This report provides users of tractor-mounted winches and cable skidders with technical information on chain chokers. The report covers type of steels, chain specifications and grades, and how to inspect chains for wear elongation. The various components (e.g. sliding hooks, rings) used to assemble chain chokers are also discussed.
Communiqué Technique No: Routes et Ponts ; CTRP 32
L'industrie forestières canadienne construit plus de 17 000 km de route par année, soit en investissement annuel de plus de 300 millions de dollars. Une base de données a été construite à l'aide des résultats du sondate et sera révisée annuellement.