Verification Method B1/VM1

The first Verification Method for clause B1 Structure is known as Verification Method B1/VM1 or simply B1/VM1. It cites several New Zealand and Australia/New Zealand standards as a means to design structures that meet the seismic performance requirements of the Building Code. For any particular building, Verification Method B1/VM1 generally consists of AS/NZS 1170 Structural design actions and a compatible design standard for each specific material (concrete, steel, etc). In some cases, these may be modified slightly by the Verification Method.

Most structures designed using a specific design process follow Verification Method B1/VM1.

In February 2014, the complete list of documents and standards referenced by Verification Method B1/VM1 was:

  • AS/NZS 1170 Structural design actions
  • NZS 1170.5 Structural design actions – Part 5: Earthquake actions – New Zealand
  • AS/NZS 1664.1:1997 Aluminium structures – Limit state design
  • AS/NZS 1748.1:2011 Timber – Solid – Stress-graded for structural purposes – General requirements
  • NZS 3101.1:2006 Concrete structures standard
  • NZS 3106:2009 Design of concrete structures for the storage of liquids
  • NZS 3404:1997 Steel structures standard – Materials, fabrication, and construction with the relevant provisions superseded by NZS 3404.1:2009
  • NZS 3603:1993 Timber structures standard
  • NZS 3622:2004 Verification of timber properties
  • AS/NZS 3725:2007 Design for installation of buried concrete pipes
  • AS/NZS 4058:2007 Precast concrete pipes (pressure and non-pressure)
  • NZS 4211:2008 Specification for performance of windows
  • NZS 4219:2009 Seismic performance of engineering systems in buildings
  • NZS 4230:2004 Design of reinforced concrete masonry structures
  • NZS 4297:1998 Engineering design of earth buildings
  • NZS 4402:1986 Methods of testing soils for civil engineering purposes
  • NZS 4431:1989 Code of practice for earth fill for residential development
  • AS/NZS 4600:2005 Cold-formed steel structures
  • SNZ HB 8630:2004 Tracks and outdoor visitor structures
  • New Zealand Geomechanics Society, Guidelines for the Field Descriptions of Soils and Rocks in Engineering Use, 1988
  • National Association of Steel-framed Housing, NASH Standard – Residential and Low-rise Steel Framing, Part 1: Design Criteria, 2010
  •  Verification Method B1/VM4 Foundations
  • Changes to the seismic hazard factor (Z) referenced in AS/NZS 1170 Structural design actions for specific areas of Canterbury following the Canterbury earthquakes.

If a designer uses the Verification Method as the means of compliance, there are sometimes options available for seismic design of building elements. AS/NZS 1170 is the primary source for defining seismic design actions and design methods. The main material standards (concrete, steel, timber) provide design methods specific to those materials. Other standards within the Verification Method may provide seismic design actions and design methods to follow for some generic applications, such as engineering systems or fire protection. The designer can choose the option within the Verification Method that is most appropriate to their particular application.

AS/NZS 1170 Structural design actions

AS/NZS 1170 Structural design actions, which is actually a series of related documents collectively referred to as the loadings standard, consists of five parts covering a range of structural design issues. Each part was written at a different time. The most relevant to the design of seismically resilient buildings is NZS 1170.5:2004 Structural design actions – Part 5: Earthquake actions – New Zealand.

This part of the standard is highly technical. It is intended to provide methods for structural engineers to determine earthquake loading levels and specifications and to determine the seismic design loads and design methods for buildings and elements.

NZS 4219:2009 Seismic performance of engineering systems in buildings

NZS 4219:2009 Seismic performance of engineering systems in buildings sets out general objectives and seismic performance requirements for engineered systems related to the normal functioning of the building, in particular, building services. It covers the design, construction and installation of seismic restraints for these engineered systems.

NZS 4219:2009 covers components, such as boilers, that do not form part of the primary structure, but excludes contents or items that are not attached to the building structure, such as portable appliances and process plant. Such a large mass is very likely to alter the seismic response of the overall structure, invalidating assumptions about the building configuration made in the loading standard and making it necessary to carry out a special seismic analysis.