AS/NZS 1170.3:2003/Amdt 1/2007-04-02 STANDARDS AUSTRALIA/STANDARDS NEW ZEALAND Amendment No. 1 to AS/NZS 1170.3:2003 Structural design actions Part 3: Snow and ice actions CORRECTION The 2003 edition of AS/NZS 1170.3 is amended as follows; the amendment should be inserted in the appropriate place(s). SUMMARY: This Amendment applies to the Preface, Clauses 1.1, 1.2, 1.3, 1.4, 2.2(c), 5.1, 5.2, Table 5.1, Figures 5.1 to 5.7 and Appendix A. Published on 2 April 2007. Approved for publication in New Zealand on behalf of the Standards Council of New Zealand on 19 January 2007. AMDT No. 1 APR 2007 Preface 1 Delete the third paragraph 2 Delete the fifth paragraph and replace with the following: This Standard is Part 3 of the AS/NZS 1170 series, Structural design actions, which comprises the following parts, each of which has an accompanying Commentary published as a Supplement: AS/NZS 1170.0 1170.1 1170.2 1170.3 Part 0: Part 1: Part 2: Part 3: General principles Permanent, imposed and other actions Wind actions Snow and ice actions AS 1170.4 Part 4: Earthquake actions NZS 1170.5 Part 5: Earthquake actions—New Zealand 2 In the sixth paragraph delete ‘2002’ and replace with ‘2003’. 3 Add the following at the end of the Preface: AS/NZS 1170.3 is independent of the design requirement specified—thus becoming a purely technical document. It may be used to calculate snow depths and roof loads given any annual probability of exceedance. The annual probability of exceedance (P) defines the snow or ice event (in which pressures and forces occur). Thus a high accumulation of snow with an annual probability of exceedance in the range of 1/200 to 1/2000 is used for ultimate limit states, while a much more frequent event (say of 1/20 or 1/25) might be used for serviceability limit states. In AS/NZS 1170.3, Section 5 gives the ground snow loads factored for selected annual probabilities of exceedance using the probability factor kP and Section 4 sets out the determination of the snow actions (roof loads) that are appropriate for the annual probability specified. ISBN 0 7337 8132 2 1 APR 2007 AMDT No.4 Add the following: NOTE: Snow and ice actions may be determined for either ultimate or serviceability purposes. Information on serviceability conditions and criteria can be found in AS/NZS 1170.2 (c) Delete ‘AS (Southern Tablelands. 1 APR 2007 AMDT No. Page 16 Clause 5.0 gives requirements for New Zealand structures and for Australian structures not covered by the BCA. Clause 2.The annual probability of exceedance is not defined in AS/NZS 1170. 2 Delete the ‘4’ from second line of second paragraph. . AS/NZS 1170. New South Wales and Victoria)’.2 Add the following Note: NOTE: Use of methods or information not given in this Standard should be justified by a special study (see AS/NZS 1170.0 for loads associated with an appropriate annual probability of exceedance (P) for serviceability. Clause 1. but is set out in AS/NZS 1170.3. 1 APR 2007 AMDT No. New South Wales)’ and replace with ‘AS (Southern Tablelands. Clause 1.0).3 Make the following changes to Clause 1.4 for sub-alpine regions. 1 APR 2007 AMDT No. AMDT No.3. which is regarded as Part 3 of the AS/NZS 1170 series of Standards (see Preface). 1 APR 2007 Clause 1. Such values calculated using the applicable annual probability of exceedance (P) would be used in the combinations given in AS/NZS 1170. the words ‘this Standard’ indicate AS/NZS 1170.1 Add the following Note: NOTE: In this document. Guidance for serviceability events and associated limits is given in an informative Appendix of AS/NZS 1170.1 1 Delete the first paragraph and replace with the following: Values for the site ground snow load appropriate for regions in Australia and New Zealand where snow action occurs shall be as given for Australia and New Zealand in Clause 5. AMDT No.3 for alpine regions and Clause 5.0 [and by further reference for ultimate limit states in the BCA (Table of annual probabilities of exceedance) and in the Guide to the BCA (examples of structures for importance levels)].0.0 as S u or Ss as appropriate. 1 APR 2007 Clause 1.3: 1 Delete title ‘REFERENCED DOCUMENTS’ and replace with ‘NORMATIVE REFERENCES’ 2 Delete reference to ISO 12494 3 Add note as follows: NOTE: Informative documents referred to in this Standard are listed in Appendix A. 65 1.3 1.35 1/200 1/150 1/100 1. AMDT No.7 and replace with the following: . 1 APR 2007 Table 5.0 0. 2 The values given for New Zealand are calculated from the following equation rounded to the nearest 0.65 1.85 1.1 PROBABILITY FACTOR (kP) Annual probability of exceedance of the action Probability factor (k P) (P) Australia New Zealand 1/2500 1/2000 2.7 Delete Figures 5.35 2.22.05: k p = 0.1 to 5.8 NOTE: AMDT No.18.25 1.1 Delete Table 5.AMDT No. 1 APR 2007 Clause 5. Figures 5.4 1.1 and replace with the following: TABLE 5.15 1/50 1/25 1/20 1. 1 APR 2007 1 The values given for Australia are calculated from the following equation with appropriate rounding: k p = 0.2 1.26ln(1/P) + 0.8 1/1000 1/500 1/250 2.215ln(1/P) + 0.05 1.25 1.5 1.0 1.2 Delete second sentence from first paragraph.85 1.1 to 5.05 1.6 1.85 0.5 1. FIGURE 5. All altitudes in Regions AN and AC are sub-alpine.2 should be used for design.1 REGIONS AN AND AC—GROUND SNOW LOAD (s g) FOR PROBABILITY OF EXCEEDANCE OF 1/150 and 1/200 (SUB-ALPINE) NOTE: This Figure is provided as a quick check only. Values above 20 kPa are not shown.NOTE: This Figure is provided as a quick check only.4 and the appropriate kP factor from Clause 5.3 and 5. FIGURE 5.2 should be used for design. Error bars show range of values for kt factor (1/150 only).4 and the appropriate kP factor from Clause 5. Clauses 5. Clauses 5.2 REGION AS—GROUND SNOW LOAD (sg ) FOR PROBABILITY OF EXCEEDANCE OF 1/150 and 1/200 (SUB-ALPINE AND ALPINE) .3 and 5. SUB-ALPINE AND ALPINE) NOTE: This Figure is provided as a quick check only. FIGURE 5.2 should be used for design.3 REGION AT—GROUND SNOW LOAD (sg ) FOR PROBABILITY OF EXCEEDANCE OF 1/150 and 1/200 (TASMANIA.4 REGION N1—GROUND SNOW LOAD (sg ) FOR PROBABILITY OF EXCEEDANCE OF 1/150 and 1/250 (NORTH ISLAND.4 and the appropriate kP factor from Clause 5. SUB-ALPINE AND ALPINE) . Error bars show range of values for kt factor (1/150 only).3 and 5. Clauses 5.3 and 5. Clauses 5. FIGURE 5. Values above 20 kPa are not shown.NOTE: This Figure is provided as a quick check only.2 should be used for design.4 and the appropriate kP factor from Clause 5. Values are specified up to 1800 m.6 REGION N2 AND N3—GROUND SNOW LOAD (s g) FOR PROBABILITY OF EXCEEDANCE OF 1/150 and 1/250 (SOUTH ISLAND.4 and the appropriate kP factor from Clause 5.2 should be used for design. FIGURE 5.2 should be used for design. ALPINE ONLY—GROUND SNOW LOAD (sg) FOR PROBABILITY OF EXCEEDANCE OF 1/150 and 1/250 NOTE: This Figure is provided as a quick check only. SUB-ALPINE AND IN PART ALPINE) .4 and the appropriate kP factor from Clause 5.3 and 5. Clauses 5.NOTE: This Figure is provided as a quick check only. Clauses 5.5 SOUTH ISLAND.3 and 5. FIGURE 5. 1 APR 2007 Appendix A (new) APPENDIX A BIBLIOGRAPHY (Informative) ISO 12494 Atmospheric icing on structures . Values are specified up to 1800 m.7 REGION N4 AND N5—GROUND SNOW LOAD (s g) FOR PROBABILITY OF EXCEEDANCE OF 1/150 and 1/250 (SOUTH ISLAND. SUB-ALPINE AND IN PART ALPINE) AMDT No.3 and 5.NOTE: This Figure is provided as a quick check only.2 should be used for design. FIGURE 5. Clauses 5.4 and the appropriate kP factor from Clause 5.