The Constitution Place development comprises redevelopment of a car park site in Canberra CDB to accommodate a new 13-strorey mixed use development, to include 3 levels of basement car parking.
The project required that initial bulk excavations extend to about 12 m below surrounding levels, within variably weathered dacite bedrock, of typically medium to extremely high strength.
The works were carried out within the CBD environment, immediately adjacent to the Canberra Theatre and the Australian Capital Territory Legislative Assembly Building.
D&N were engaged by the preferred Civil contractor to provide construction stage geotechnical engineering consultancy for the bulk excavation works.
Our role included provision of temporary works advice, and ongoing vibration monitoring to manage the potential impacts of the works on adjacent sensitive structures.
We deployed three vibration monitoring stations over a six-month period, with provision of real time monitoring data and implementation of a traffic light beacon and SMS exceedance alert, set to advise the foreman and project manager should exceedances occur.
Vibration monitoring required D&N to liaise directly with stakeholders to allow installation of equipment, maintenance, and data collection within agreed time windows to avoid causing disruption to existing adjacent site users.
D&N were involved in the stakeholder liaison process, providing weekly updates to the project team, and assisting with stakeholder management/response to alleviate concerns and keep the program on track.
D&N opted for use of the German DIN set of standards to consider vibration limits with respect to risk to property and prolonged human exposure.