ISA and DSA Assessments
ACH can assist with ISAs and DSAs as required by insurance or financial organisations, for property sales/purchases, or for the Local Authority/Council. ISAs and DSAs are tools for measuring the intrinsic seismic strength of a building, in the context of today's design standards/codes.
The ISA is a qualitative 'broad brush' tool which is useful for generic purposes or in a 'triage' role, and is largely dependent on the buildings age and construction type.
By comparison the DSA is a more detailed quantitative tool which involves analysis of the existing records, targeted calculations and modelling, and, based upon the level of information available and the confidence in it's accuracy, some non-invasive (x-ray, CCTV) or invasive (core sampling, excavation) testing.
Based on the outcome of either an ISA or DSA, ACH can identify and develop conceptual strengthening solutions for costing purposes, and also assist with detailed design and consenting for physical works.
These procedures have been developed by the New Zealand Society for Earthquake Engineering (NZSEE), and as a result of our involvement in the Christchurch rebuild and local demand since, ACH have accumulated significant expertise in both.