Colmar Brunton Building Seismic Assessment, Wellington, NZ

The Colmar Brunton Building is located in Wellington and consists of seven elevated reinforced concrete floor levels above ground level constructed in the 1920s. Additional penthouse levels of light timber and steel construction that were added as part of changes in 1985.

A nonlinear pushover analysis was undertaken to assess the seismic performance of the building using using the ETABS finite element analysis program.

The analysis model considered nonlinear behavior such as combined axial – moment interaction for walls and columns, moment hinging for the beams and an allowance for pad foundation uplift and plastic shear deformation of the walls.

The sophisticated modeling approach adopted, allowed for the structure to be assessed as having sufficient strength to meet current regulatory requirements.