1、 Reference number ISO/TR 12910:2010(E) ISO 2010TECHNICAL REPORT ISO/TR 12910 First edition 2010-04-01 Light-frame timber construction Comparison of four national design documents Construction ossature lgre de bois Comparaison de quatre documents nationaux pour la conception ISO/TR 12910:2010(E) PDF
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6、Os member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2010 All rights reservedISO/TR 12910:2010(E) ISO 2010 All rights reserved iiiCon
7、tents Page Foreword .v Introductionvi 1 Scope1 2 Document design principles 1 2.1 Basic principles .1 2.2 Compliance through pre-engineered solutions .2 2.3 Design requirements matched to risk level2 2.4 Relationship to engineering design 3 2.5 Evolving understanding of load-resistance interaction3
8、3 Coverage and limitations3 3.1 General .3 3.2 Definition of light-frame construction .4 3.3 Prescriptive and performance-based approaches.4 3.4 Integration of national code provisions4 3.5 Scope of structural design .5 3.6 Beyond structural requirements, such as durability .5 4 Loads and load facto
9、rs .6 4.1 General .6 4.2 Basic design framework and philosophy .6 4.3 Load comparisons.6 5 Material specifications7 5.1 General .7 5.2 Product standards.7 5.3 Proprietary wood products.7 6 Member design 7 6.1 General .7 6.2 Member vs. system design.8 6.3 Roofs.8 6.4 Walls .9 6.5 Floors9 7 Lateral lo
10、ad systems design 9 7.1 General .9 7.2 Linking lateral design to analysis models 9 7.3 Load action assumptions .10 7.4 Uplift design.10 7.5 Racking and overturning design .11 7.6 Building plan irregularities.11 7.7 Wall openings 11 7.8 Elevation irregularities12 8 Connection design 12 8.1 General .1
11、2 8.2 Fastener schedules .12 8.3 Proprietary connections .13 9 Other .13 9.1 Miscellaneous 13 9.2 Definitions of terminology13 ISO/TR 12910:2010(E) iv ISO 2010 All rights reservedAnnex A (informative) Comparison chart .15 Bibliography 50 ISO/TR 12910:2010(E) ISO 2010 All rights reserved vForeword IS
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16、(“state of the art”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful. Atte
17、ntion is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TR 12910 was prepared by Technical Committee ISO/TC 165, Timber structures. ISO/TR 12910:2010(E) vi I
18、SO 2010 All rights reservedIntroduction Light-frame timber construction is the dominant construction practice for housing and other types of buildings in some countries. In these countries, it has gained widespread acceptance due to its many benefits, including ease of construction, cost-effectivene
19、ss, adaptation to energy efficient buildings and proven performance. This Technical Report is intended to provide an overview of the common elements in existing national structural design documents on light-frame timber construction. The comparison chart (see Annex A) is intended to assist in that p
20、rocess. This Technical Report draws attention to several common themes and identifies some differences in the documents reviewed. TECHNICAL REPORT ISO/TR 12910:2010(E) ISO 2010 All rights reserved 1Light-frame timber construction Comparison of four national design documents 1 Scope This Technical Re
21、port provides an introduction and synopsis of comparisons among the following four national design documents on light-frame timber (wood) 1)construction: a) AS 1684-1 (including AS 1684-1:1999/Amd.1:2002), AS 1684-2 and AS 1684-3; b) the Engineering guide for wood-frame construction; c) NZS 3604; d)
22、 the Wood Frame Construction Manual (WFCM) for One- and Two-Family Dwellings (Chapter 1: General information, Chapter 2: Engineered design and Chapter 3: Prescriptive design). Each of the four light-frame texts compared in this Technical Report is based on a national timber design standard that incl
23、udes provisions for assemblies and systems, which go beyond single-member design methodology. Other jurisdictions also have similar design documents on light-frame timber construction. Although not all jurisdictions have design documents on light-frame timber construction, timber design standards ty
24、pically address assemblies and systems (See 6.2). 2 Document design principles 2.1 Basic principles AS 1684-1, AS 1684-2, AS 1684-3, the Engineering guide for wood-frame construction, NZS 3604 and the Wood Frame Construction Manual each comply with a national code, which defines the higher level bui
25、lding design principles and conditions that need to be met for light-frame timber buildings, including strength and serviceability criteria, specified loads and material design performance. In general, AS 1684-1, AS 1684-2, AS 1684-3, the Engineering guide for wood-frame construction, NZS 3604 and t
26、he Wood Frame Construction Manual (design documents) share basic principles related to demonstrating how light-frame timber construction can comply with structural requirements, particularly how it can resist high-wind and/or seismic loading conditions and provide additional guidance concerning syst
27、em design and construction methods. At the same time, AS 1684-1, AS 1684-2, AS 1684-3, the Engineering guide for wood-frame construction, NZS 3604 and the Wood Frame Construction Manual do not all seek to have the same coverage or topics (see Clause 3). Some deal with housing only, others with housi
28、ng and small buildings; a few with wood structural design only and others with other structural components or design aspects of the building. These differences complicate direct comparisons of the documents on a detailed level. The following are some observations on general principles found. 1) The
29、terms “wood” and “timber” are used interchangeably in this Technical Report. ISO/TR 12910:2010(E) 2 ISO 2010 All rights reserved2.2 Compliance through pre-engineered solutions To demonstrate how to comply with national code requirements for light-frame wood construction, pre-engineered solutions and
30、 tables to accompany engineering design methods are included in AS 1684-1, AS 1684-2, AS 1684-3, the Engineering guide for wood-frame construction, NZS 3604 and the Wood Frame Construction Manual. This approach can be more conservative in some cases, but can also facilitate design and regulatory che
31、cking, particularly in areas less familiar with the construction system. The following are examples. AU: AS 1684-1, AS 1684-2 and AS 1684-3 cover design of timber-framed construction conforming to loading and performance requirements for Class 1 (housing or hostels) and Class 10 (non-habitable struc
32、tures) buildings as defined by the national code; less conservative designs can be permitted by other building regulations or standards. CA: The Engineering guide for wood-frame construction covers a subset of the national code Part 9 (Housing and small buildings). Part 9 typically permits less cons
33、ervative measures for housing and small buildings, particularly for buildings subjected to significant lateral loading. NZ: NZS 3604 provides acceptable “non-specific” design solutions to the performance-based national code, including many detailed construction provisions. US: The Wood Frame Constru
34、ction Manual is referenced in US national codes for design of wood-frame construction, particularly in higher wind and seismic conditions; other provisions permit less conservative conventional construction or engineered designs. 2.3 Design requirements matched to risk level 2.3.1 General AS 1684-1,
35、 AS 1684-2 and AS 1684-3, the Engineering guide for wood-frame construction, NZS 3604 and the Wood Frame Construction Manual all, in one way or another, match design provisions to the type and intensity of loading as well as vulnerability of the building structure. This can in some cases lead to des
36、ign discontinuities where special solutions are specified only for high- or low-risk areas, but also helps to provide a better fit to the scale of the problem. 2.3.2 Examples AU: Separate cyclonic and non-cyclonic documents deal with high- or low-risk cyclonic events. AS 1684-1, AS 1684-2 and AS 168
37、4-3 increase requirements for higher risk areas, with up to half of racking force permitted to be resisted by nominal wall bracing; AS 1684-2 is published for simplified design in non- cyclonic areas. CA: Part C of the Engineering guide for wood-frame construction advises on applicability of solutio
38、ns under lateral loading conditions, based on spacing and location of braced walls; national codes permit prescriptive construction that are more liberal than Part C of the Engineering guide for wood-frame construction. NZ: Prescriptive provisions include restrictions on bracing elements in terms of
39、 spacing, minimum capacity and location; if spacing of bracing lines not evenly distributed, spacing is reduced to coincide with a line of supporting members. US: Separate “prescriptive design” document in tabular format is based on engineering principles; national codes permit conventional construc
40、tion in lower risk situations. ISO/TR 12910:2010(E) ISO 2010 All rights reserved 32.4 Relationship to engineering design AS 1684-1, AS 1684-2, AS 1684-3, the Engineering guide for wood-frame construction, NZS 3604 and the Wood Frame Construction Manual share the objective of maintaining continuous l
41、oad paths, but it is recognized that they cannot fully replace the design process. Common themes include agreement that not all aspects of the complete structure are fully addressed and conservative assumptions are made to present efficient design aids. The documents are intended to be used principa
42、lly by engineers or other competent designers. The following are examples. AU: Intended to provide building industry with design procedures and details for use in cyclonic and non-cyclonic areas; another simplified version (AS 1684-4) was published for non-designers. CA: Intended to be used in conju
43、nction with competent engineering design, as well as to provide guidance to a wide range of the building community (e.g. builders, code officials). NZ: Intended to be used by a wide range of the building industry, while recognizing that due to national code requirements, users would be mainly fulfil
44、ling the role of a designer. US: Intended to be used in conjunction with competent engineering design, providing guidance and saving time for the design professional. 2.5 Evolving understanding of load-resistance interaction There is widespread recognition of the complexity of load and resistance di
45、stribution and interaction in light-frame construction systems under gravity and lateral loading patterns. AS 1684-1, AS 1684-2, AS 1684-3, the Engineering guide for wood-frame construction, NZS 3604 and the Wood Frame Construction Manual include varying approaches to incorporating system action pro
46、visions and calibrating to the long performance history of these systems. These provisions are likely to evolve to include more advanced design tools as knowledge grows. The following are examples. AU: Load distribution and strength-sharing effects are included in design methods for framing members,
47、 including rafter, studs and joists. CA: Design of rafters, studs, joists, headers and beams includes consideration of system action and strength sharing; shearwall design is a mechanics-based approach with additional consideration of shearwalls without hold-downs where sheathing is used to resist o
48、verturning and/or uplift. NZ: Nominal bracing systems are provided with prescribed bracing capacities; performance-based design (national code) permits use of alternative design solutions. US: Wall stud design includes system factors, load-sharing increase factors provided for joists, rafters and ot
49、her members; shearwall design includes a mechanics-based approach for shearwalls with hold-downs with additional consideration of the empirical based perforated shearwall model (without hold-downs). 3 Coverage and limitations 3.1 General The light-frame construction documents are limited in terms of building size, loads and other parameters. These limits are dictated largely by national codes, yet committees also make many decisions on what to include within the scope and limitations of light-frame constructio
