Understanding NZS 3604:2011 modifications
The standard NZS 3604:2011 Timber-framed buildings, and its modification for concrete slabs, is an Acceptable Solution (B1/AS1) for Building Code clause B1 Structure. If you are following B1/AS1, this nationally-applied modification requires you to reinforce all concrete slabs with ductile steel and that you only use details that require perimeter footings to be tied to the slab. You cannot use unreinforced slabs anywhere in New Zealand. You can choose an alternative means to comply with B1.
As an Acceptable Solution, it:
is suitable where there is “good ground” as defined in that Standard
applies to all regions in New Zealand as it stands, except in the Canterbury earthquake region
applies to the Canterbury earthquake region with a modification to the definition of “good ground”. The modification excludes ground subject to liquefaction or lateral spread.
The Canterbury earthquake region amendment does not yet apply nationally. This is because the potential loss of structural support due to liquefaction or lateral spread is complex and not sufficiently well defined to incorporate in the B1 Building Code clause acceptable solution or verification method.
Lessons are still being learnt from Christchurch, and work needs to be done with other Councils to provide some certainty, so that individual engineering investigations are not required for every property.
This includes:
properly specifying expected performance requirements
identifying the conditions they apply to
outlining how to assess those conditions in a practical and cost effective manner
providing cost effective construction solutions.
MBIE is researching this, and will develop proposals for consultation that would provide robust and effective support for an amended definition of good ground in locations other than the Canterbury Earthquake region. In the interim, MBIE has issued the guidance.
补充内容 (2021-9-20 21:35):
applies to the Canterbury earthquake region with a modification to the definition of “good ground”. The modification excludes ground subject to liquefaction or lateral spread.
补充内容 (2021-9-20 21:35):
applies to the Canterbury earthquake region with a modification to the definition of “good ground”. The modification excludes ground subject to liquefaction or lateral spread.作者: songinator 时间: 2021-9-20 22:35:24
