The Sydney Metro Northwest project will be the first fully-automated metro rail system in Australia and will deliver eight new railway stations, 4,000 commuter car parks and a new high frequency single deck train system to support Sydney’s growing North West.

Trains will operate every four minutes in the peak with at least 15 trains per hour. John Holland has been awarded two packages of work for the Sydney Metro Northwest.

BG&E’s highly-skilled materials team was engaged by SMEC to provide investigation and assessment services to assist with the certification of the four-kilometre viaduct structure on the Northwest line. This work became necessary after the failure of some spans on the viaduct, during post-tension strand stressing.

Our multi-disciplinary team of materials and structural engineers assessed all installed spans, precast segments awaiting installation, and constructed piers and crossheads. This involved working closely with other consultants, as well as with the construction consortium to facilitate access and to undertake testing and inspection works.

The elements were inspected and reported on within a six-week period, which enabled certification by Transport for New South Wales (NSW). Any necessary rectification works could be undertaken thereafter.

Following the completion of the testing and assessments, BG&E was reengaged to provide a broader range of testing and durability services, including:

• supervision of site works associated with key structural elements, and inspection of activities in association with the design engineer;
• testing of concrete in tunnel inverts for conformance verification;
• assistance in the optimisation of precast element design to improve production program;
• inspection of precast production to verify conformance to project specifications;
• provision of shop drawing drafting capability to assist with precast production; and
• other materials advisory services as issues arose during construction.

This schedule of works continued for approximately two years.