Posted: 24 November 2014
This Building Controls Update is a periodic news bulletin for the building sector.
MBIE have released further worked examples to accompany the technical guidance on the seismic design of retaining structures for residential sites in greater Christchurch.
These worked examples include concrete cantilever, anchored and crib retaining walls. Some minor modifications have also been made to the main guidance document and the worked example already issued (cantilever timber pole wall).
The new guidance on retaining walls will now comprise:
|Supplementary guidance on retaining walls||Version 2|
|1. Cantilever timber pole wall||Version 3|
|2. Concrete cantilever wall||Version 1|
|3. Anchored wall||Version 1|
|4. Crib retaining wall||Version 1|
Please update your retaining walls documents with the above versions.
The modifications made to the supplementary guidance document are annotated and include:
- Section 2 including the latest GNS reference regarding mass movement areas and the addition of “or” between Points 1 and 2.
- Changes and additions have been made to text in Sections 7.4, 7.6.1 and 8.2.2.
- Appendix A – “Application of Mononobe-Okabe equations with high acceleration and/or high back-slope angle” has been added which provides commentary and graphs for the estimation of KAE.
The retaining walls guidance is supplementary to the Guidance document ‘Repairing and rebuilding houses affected by the Canterbury earthquakes’, December 2012.
It is intended for engineers and designers of retaining walls and for building consent officers. It shows how to incorporate the effects of earthquake shaking into the design loadings for residential retaining walls.
Revised supplementary guidance and the associated worked examples for the seismic design of retaining structures for residential sites in greater Christchurch