With a category I heritage building requiring seismic strengthening and a significant new architectural structure together on a landmark site, the project was unique.
A $80M project of this magnitude over several years, demanded continuously balancing the functional requirements, integrity of the architecture, heritage values, cost and timeframes to ensure no element was compromised by another.
Design options were developed and considered and a cost benefit analysis established the preferred solution for base isolation. At the same time, similar assessment was undertaken for the seismic design of the new Supreme Court building which connected at both ground floor and basement level to the Old High Court Building.
The assessment identified that a conventional piled and ground beam foundation with movement frame and floor / roof diaphragms provided the optimum solution. Both solutions achieved the same design standard as set for the importance level of the facilities.
Whilst the Base Isolation solution for the Old High Court Building provided the best outcomes, the retro fitting of the isolators and the location of the separation plane into the building also created significant challenges in regards to methodology, temporary works design, seismic risk through construction and associated insurance provisions, building services separations and programme.
TBIG’s governance was critical in identifying and developing a number of innovations including early direct procurement of isolator bearing supply, utilisation of a separate enabling contract to accelerate early works and de-risk impact of archaeological discoveries, establishment of ground acceleration performance standards for temporary works design and monitoring mechanism’s, consultation frameworks for engagement with heritage stakeholders to provide clear rules controlling allowable intrusion and impact assessment on heritage values. A collaborative approach with an active and engaged client and project team, ensured this high-profile project on budget and on time.