Murujuga Bridge, Karratha

Hera Engineering is engaged to undertake the structural works for the delivery of the Murujuga Bridge in Karratha for the City of Karratha. Hera’s scope of works consists of undertaking schematic design to project delivery for the delivery of the bridge. Hera has worked with the project team to explore alternative design solutions to satisfy the projects complex social, environmental, and financial constraints in this remote location.

The project key constraint is providing an economical bridge solution over the existing 80m wide creek with consideration of the environmental and social constraints. Protected species of flora are present within this creek, modification of earthworks or blockages (bridge supports) may negatively impact the water flows and longevity of this respective species. Hera has worked closely with the project team and stakeholders, inclusive of traditional owner group to explore various bridge support arrangements within these respective constraints to deliver the best outcomes for the project.

The M-Lok modular prestressed system has proven a cost-effective solution for the superstructure considering the logistics limitations within this remote region. These precast units have significantly better design performance in this aggressive coastal environment. Hera has worked closely with construction contractors to cost and identify significant cost savings. Hera has worked with the necessary parties (geotechnical, hydraulic and Statutory bodies) to explore reduction in overall span by widening abutments and implementing scour protection measures to satisfy the sensitive constraints. Further, the use of alternative in-situ shallow foundations with rock anchors (in lieu prestressed piles with rock sockets) are being investigated for suitability pending additional geotechnical testing. This will provide significant cost savings (10-15%) as a piling rig will not need to be mobilised to this remote area.