IEP and DEE Seismic Assessments

Building owners throughout the country are under pressure to demonstrate the adequacy of their buildings to resist earthquake loads. This is generally being manifested in two ways. Primarily, insurers and funders are insisting on seismic assessments, demonstrating that the building is not earthquake prone. This may be to either secure building finance and/or insurance. Tenants are also ‘voting with their feet’ with a flight to buildings that are considered less of a seismic risk. The other source of pressure is from local authorities, who are identifying potentially earthquake prone buildings by carrying out initial evaluation procedure (IEP) assessments and reports. An IEP is a qualitative assessment largely influenced by the building age and type of construction. The affected building owner may then be advised to carry out their own IEP assessment. This may ultimately result in the requirement for seismic strengthening to the building.

 

 

A DEE is a more detailed evaluation, a quantitative assessment. It is intended to provide an accurate assessment of the buildings capacity to withstand an earthquake event. Unlike the IEP, a DEE is likely to require some form of site testing and measurement, as well as analysis and calculation. It is akin to designing a building backwards by determination of the capacities of the existing building elements and systems.

Initial Evaluation Procedure (IEP)

Our methodology follows that as set out in the New Zealand Society of Earthquake Engineering Guidelines 2006, and includes:

  • Review of all available property information
  • Site visit to carry out a visual inspection
  • Record of overall measurements if not available from existing records

The subsequent report includes:

  • Description of the building
  • Executive summary of salient report finding including:
  • Evidential structural weaknesses
  • Overall rating of the structure (percentage of New BuildingStandard (%NBS))
  • Appendices:
  • Assessment calculation sheet
  • Selected marked up drawings

Detailed Engineering Evaluation (DEE)

Following a review of all available property records and a site inspection, a typical report would include:

  • Executive summary
  • Description of methodology
  • Detailed description of the bracing elements
  • Summary of results
  • Critical members %NBS
  • Overall rating of the structure
  •  Initial scope of remedial works to achieve building owners desiredoverall %NBS rating
  • Rough order of costs to achieve building owners desired overall%NBS rating

 

 

IEP DEE Earthquake Assessment