AS/NZS 1170.0 Supp 1:2002 (R2016)

Provides background material to the requirements of AS/NZS 1170.0, General principles. Clause by clause, it gives the origins of requirements, departures from previous practice and explanations with examples to illustrate their application.

Scope

This Commentary is intended to be read in conjunction with AS/NZS 1170.0:2002. It explains the provisions of and, in some cases, suggests approaches that may satisfy the intent of the Standard. Commentary Clauses are not mandatory. Lists of references are also given for further reading.
The Standard (AS/NZS 1170.0) has been revised as a joint Australian/New Zealand Standard. It specifies the basic procedure for the structural design of structures including buildings. Other documents may be relevant for the details of building design (e.g., design of fire escapes) that are not needed for the design of the structure.
The Standard incorporates the fundamentals of the limit states method and enables the designer to confirm the design of a structure. The intention is that confirmation establishes the ability of the proposed structure to resist known or foreseeable types of action appropriate to the intended use and design working life of the structure.
The determination of structural resistance is covered by the Standards for design of materials.
Much of the philosophy and some of the text (for example, most of the definitions and notation) are drawn from ISO Standards, including ISO 2394, ISO 3898, ISO 4356 and ISO 8930.
The general principles given in the Standard are relevant to the design of any structure. However, the information may not be sufficient for some structure types because their design is more complex (due to the inherent behaviour of the structure) or involves loadings that are not covered (type of action or load case), or other Standards give design criteria. Structures and structural elements should be designed so that they are suited for their intended use during the design working life.
ISO 2394 states the following:
‘In particular, they shall fulfil, with appropriate degrees of reliability, the following objectives:
(a) They shall perform adequately under all expected actions.
(b) They shall withstand both extreme actions and frequently repeated actions occurring during their construction and anticipated use.
(c) They shall have structural robustness.’
These three objectives enunciate the serviceability, ultimate and fatigue, and progressive collapse (structural robustness) aspects of design.
SPECIAL STUDIES
Where methods or information used in a design are outside the scope of the Standard
justification would normally be required for approval under building regulations. This
would require a ‘special study’. A special study is a means of establishing information for
use in design that is not specifically stated in the Standard. This may include information
varied from or not included in the Standard (see Appendix A and its Commentary). The results of such special studies are outside the scope of the Standard.
Special studies may be carried out at the initiative of the designer for any building, subject to satisfying the requirements of the appropriate authority. Appendix B covers testing as part of a special study.
Appendix CA gives additional information on actions not covered, including—
(i) movement effects;
(ii) construction loads; and
(iii) accidental actions.
OTHER STRUCTURE TYPES
The following publications give information useful or necessary for the design of the
structures indicated:
(A) HB77 for bridges.
(B) AS 4678 for earth-retaining structures.
(C) AS 3995 for lattice towers and masts, including electrical transmission structures.
(D) AS 3962 for marinas.
(E) AS 3826, ISO 2394 and ISO 13822 for assessment of existing structures.
(F) AS 2159 for piling.
(G) AS/NZS 4676 for utility services poles.
(H) AS 1418 for cranes.
(I) AS/NZS 1576 for scaffolding.
(J) AS 3610 for formwork.
(K) AS 2156.2 for walking track structures.
The design of chimneys may require the use of specialist publications.
Off shore structures require additional information on winds, waves, currents and
earthquake.
High-risk structures that require special reliability consideration (such as dams) are
generally covered by the special requirements of the regulatory authorities responsible for
them.