STRUCTURAL SYSTEMS DESIGNED FOR NEW ZEALAND BUILDINGS

Conventional seismic systems often rely on ductility through yielding structural members.

Depending on the structure, this can result in:

• higher capacity-design actions
• greater demand on connections and foundations
• residual deformation after a significant event
• more extensive intervention when strengthening existing buildings

Purpose-designed damping systems dissipate earthquake energy within controlled devices rather than relying solely on structural yielding.

Potential system-level benefits include:

• reduced seismic force demand
• controlled overstrength actions
• reduced residual drift where self-centering is incorporated
• potential reductions in structural and foundation requirements

The effect is project-specific and depends on the complete structural system, seismic hazard, device properties and analysis assumptions.

Projects where Tectonus can deliver most impact

• High seismicity regions

• High importance level (IL3/4)

• Poor soils / high foundation cost

• Tall and irregular structures

• Capacity-limited existing structures

• Sensitivity to future code changes (e.g. TS 1170.5)

Tectonus systems can be designed within either the current NZS 1170.5:2004 seismic design framework referenced by B1/VM1, or using an alternative seismic demand basis where appropriate, including the newer TS 1170.5 framework incorporating the 2022 National Seismic Hazard Model.

The selected seismic design basis establishes the earthquake demands on the building. The Tectonus system is then incorporated explicitly into the structural analysis, considering its force–displacement behaviour, activation force, energy dissipation, displacement capacity and the forces transferred to the surrounding structure.

Where the proposed design methodology falls outside the scope of the Verification Method, compliance with NZBC Clause B1 can be demonstrated as an Alternative Solution, supported by appropriate analysis, testing and engineering evidence.

Regulatory Process & Approvals

Should the BCA require independent peer review, a growing number of engineering firms have experience peer-reviewing Tectonus designs. The peer reviewer provides the PS2, and Tectonus provides the PS1 (device design) as well as PS3 (manufacturing).  This regulatory process has been proven and accepted by all the main BCAs in New Zealand.