The Objective.

This seismic retrofit at Lambton House used Circular Hollow Section (CHS) bracing anchored to the concrete floor above, enhancing structural resilience.

The project faced tight tolerances, limited headroom, and access constraints, with only a small driveway and low entrance available. The marine environment also required highly durable coatings, adding complexity to the timeline and budget.

Our involvement.

Petone Engineering led the detailing, fabrication, and installation phases of the project. Our team implemented a precise strengthening scheme using CHS members to connect exterior and interior reinforced concrete beams to the slab’s underside, achieving essential diaphragm transfer.

Advanced scanning and Teckla modelling software provided accurate data on the existing structure, supporting design integration and effective collaboration with consultants.

Innovation in fabrication and assembly was critical; for example, we used FabStation model overlay software with a HoloLens 2 headset, allowing us to verify each assembly with high precision and eliminate on-site welding requirements. Pre-drilling beams based on concrete scanning also prevented costly delays or modifications.

The outcome.

This retrofit effectively strengthened Lambton House, extending its lifespan and maintaining its sustainability.

The use of durable, corrosion-resistant coatings provided additional protection in the harsh marine environment, ensuring longevity.

Through pre-fabrication and precision QA checks, Petone Engineering achieved a smooth installation, saving on costs, reducing time on-site, and enhancing safety.

The successful use of advanced technology, including the cloud-scanned Teckla models and HoloLens QA, demonstrates our commitment to innovation and quality, setting a benchmark for seismic retrofitting projects.

The successful completion of the this project saw our work lauded by the Steel Construction New Zealand (SCNZ), with Petone Engineering winning the SCNZ Excellence in Steel Awards 2024 in the Earthquake Strengthening category.