Know how your site will behave in an earthquake

Some soils lose strength in an earthquake, which can damage foundations and services. A clear seismic assessment tells you whether your site is at risk and what to do about it.

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We assess seismic hazards in line with NZGS guidance and give practical recommendations your designers can use.

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When you need us

• Sites on reclaimed land, alluvium or loose sands

• Land near streams, estuaries or the coast

• Council liquefaction or hazard overlays

• Larger buildings and subdivisions

• Due diligence on an existing site

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What's included

• Seismic site subsoil class

• Liquefaction triggering and settlement assessment, usually from CPT data

• Lateral spread assessment near free faces

• Ground improvement and foundation recommendations

• Reporting for building and resource consent

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How it works

1. Send us your plans and the site address.

2. Desk study. We review geology maps, the NZ Geotechnical Database, council records and historic aerials.

3. Proposal. You get a clear scope, fee and programme.

4. Site work. Our team carries out the fieldwork or inspections with minimal disruption to your site.

5. Report. Clear findings and practical recommendations.

6. Ongoing support. We answer council RFIs and support you through design and construction.

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Why Gibb Ritchie

• Principal-led. A director is involved in every project, from scope to sign-off.

• Chartered professionals. Work led by Chartered Professional Engineers (CPEng).

• Local experience. We know Auckland's ground, from North Shore clays and Waitematā rock to volcanic and reclaimed land.

• Practical advice. Solutions that are technically robust, commercially realistic and fit your project.

• Responsive. We know geotechnical input is often on the critical path for design, consent and construction.

• With you to the end. The same team supports you through consent and construction.