Full-Scale Simulated Seismic Field-Testing of a Post-Tensioned Glue Laminated Timber Portal Frame Structure Deploying Traditional Māori Construction Techniques

Abstract

Testing was undertaken to investigate the viability of a traditional Māori post-tensioned construction technique that incorporated modern glue-lamination manufacturing to withstand seismic loadings. A feature of the form-fit connections was that the timber members were seated into pockets. A companion numerical model was developed to confirm aspects not readily measured in the field. Vertical loading was applied at the apex via water-filled containers. Seismic loading was simulated by applying a horizontal loading system at the apex via a winch and quick-release system, involving seven pseudo-static semi-cyclic tests followed by three snap-back tests. It was established that member demands remained within capacity, that apex vertical and horizontal displacements remained within code-defined deflection limits, and that the measured damping was 7.3%. Findings are also reported for mode shapes and joint rotational stiffness. Novel aspects of the reported research included full-scale field testing at a remote site, collaborations with the local indigenous Māori community, the incorporation of both traditional and modern post-tensioned timber construction techniques, and the intentional use of a methodology for simulated loading which could be undertaken within a community setting.