Projects - Otago University Consumer and Applied Sciences Building Seismic Upgrade

This job was part of a larger Food Science project which ABL was engaged for early contractor involvement. Investigation work was carried out on the cavity stone exterior structure in conjunction with Egis Structural Engineers.

Due to the heritage stonework a lime based grout was required to be injected into the cavity construction of the entire exterior envelope of the building. Two containers of specialist lime grout was procured from Italy in the pre-construction phase. Early procurement of post-tensioning components from England also occurred.

The seismic solution was innovative and consisted of the following systems;

Consolidation Grouting 
Lime grout injection along with stainless steel ties epoxied between the inner and outer wythes to create monolithic 600mm thick exterior walls.

Diaphragms & Shearwalls
Very strong horizontal floor diaphragms were created along with concrete masonry vertical shear walls inside the existing structure. 
   
Vertical Post-tensioning System
Vertical holes were drilled in the north & south walls to allow Macalloy M30 Stainless Steel post tensioned tendons to be installed between top and bottom anchors.

Horizontal Post-tensioning System
Pairs of 22mm stainless steel stressing cable were installed internally & externally at mid height of the building and were tensioned between large stainless steel anchors.

Structural Stonework
The structural work included dismantling for drilling work and reinstating the ornate bluestone & Oamaru Stone structure.  

Heritage Upgrade
The timber windows were double-glazed and refurbished along with a new cast iron downpipe system which was required to deviate around the stressing cables.

Overall the seismic upgrade was completed with minimal effect on the original heritage appearance of this beautiful building