Current at: 21 February 2011
New edition AS 2870 - Residential Slabs and Footings released (Nat)
This information sheet has been prepared to update members on the changes to AS 2870 – 2011: Residential Slabs and Footings. The previous edition of the Standard was published in 1996.
The new edition of AS 2870 - 2011 will not be called up in the BCA until 2012. Therefore members are not required to adopt the new requirements until 2012, however this information is provided to assist members in understanding the changes and make any adjustments necessary in your businesses in the interim.
The objective of AS 2870 is to specify performance criteria and specific designs for footing systems for foundation conditions commonly found in Australia and to provide guidance on the design of footing systems by engineering principles.
This Standard places particular emphasis on design for reactive clay sites that are susceptible to significant ground movement due to moisture changes. The Standard takes into account the following:
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swelling and shrinkage movements of reactive clay soils due to moisture changes;
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settlement of compressible soils or fill;
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distribution to the foundation of the applied loads; and
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tolerance of the superstructure to movement.
Changes to the 1996 edition are as follows:
(a)
Revision of the overall Standard, such as:
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new Clause 1.6 on Articulation Requirements
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changes to definitions in Clause 1.8
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new Clause 2.3 on Estimation of the Characteristic Surface Movement
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Section 3 on Standard Designs has been updated
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new Clause 3.4 on Waffle Rafts introduced
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Section 4 on Design by Engineering Principles has been revised
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updated Clause 4.5 on Simplified Method for Raft Designs
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new Clause 5.5 on Requirements for Aggressive Soils has been introduced.
(b)
It should be noted that Site Class H has been split into Class H1 and Class H2.
(c) There is a new Appendix H on Guide to Design of Footings for Trees.
The notes that are included are for clarification and general advice only and are not part of the mandatory provisions of the Standard.
A Commentary to the Standard has been included at the back of the document. The Commentary is also for information and advice only and does not form part of the mandatory provisions of the Standard.
The layout of the Commentary follows that of the Standard. The numbering differs only in that its clauses, figures and tables are prefixed by the letter “C”. For example, Clause C3.2.1 of this Commentary refers to Clause 3.2.1 of the Standard. Clause numbers are not consecutive because where there is no commentary to a clause then it does not appear.
HIA members can contact HIA Building Services staff on
hia_technical@hia.com.au
for any enquiries about the information covered in this information sheet.
Ref No. NAT BCA 11-04
The above is intended to provide general information in summary form. The contents do not constitute specific advice and should not be relied upon as such. Formal specific advice should be sought by members with respect to particular matters before taking action. ABN 99 004 631 752