Vision + Experience = Success

Project Category

Civil Engineering

Timeframe

June 2022 – June 2024

The project was broken into a number of specific phases and packages involving investigation, assessment of deficiencies, identifying upgrade treatment options and costs, and the selection of cost-effective solutions that would best facilitate the enabling works with a particular focus on safety.

A Multi Criteria Analysis (MCA) was prepared for the 17km long road segment of Paradise Dam Road to focus prioritisation of upgrade works. The project focused on the highest scoring sections, equating to approx. 5km’s of detailed design. These locations were identified for both horizontal and vertical realignments with full width reconstruction. The design also looked at the upgrade of a number of T-intersections with minor roadways, accesses and cross drainage. All Crests along the link were assessed for capability and remedy works were designed to meet a minimum Extended Design Domain (EDD) standard. The project also included, all existing signage being removed and replaced with new signage. The design process included the identification of signs required for the road link.

The existing low level concrete floodway on Paradise Dam Road at Degilbo Creek was identified to require updates to improve immunity and reduce time of closure due to rainfall events. As Paradise Dam Road is the main access to Paradise Dam the current arrangement, which was notorious for frequent and, at times, extensive inundation was deemed to be an intolerable disruption for the future construction process for the new dam wall.

Degilbo Creek is mapped by DAF as a purple waterway and required additional environmental considerations. Comprehensive 2D flood modelling and multiple bridge pier options were assessed for the new bridge at locations both upstream and downstream of the existing floodway. The final outcome was a 3 span PSC bridge on the upstream side of the existing crossing providing significantly improved flood immunity at AEP 10% which has a reduce time of closure.  

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The design also included adjoining works on the approaches to the new bridge structure that comprised of horizontal and vertical alignment improvements, upgrading nearby Coringa Rd intersection standard (to CHR(S)) and increased formation width.  It involved sub-contracting the hydrologic and hydraulic analysis, environmental investigations and considerations, geotechnical testing and stakeholder input into the options comparison, recommendation and detailed design phases.

This project also involved investigations of the road networks in the Bundaberg and North Burnett regions that had been proposed as potential routes for heavy vehicles hauling construction materials and for construction workers and other project personnel to access the Paradise Dam site.

The investigations included traffic impact assessments, and road geometric and safety assessments to identify deficiencies, then planning-level scoping and cost estimation of treatment options. The proposed treatment options were then prioritised using a MCA process during workshops with the client to develop a list of recommended works projects within the constraints of the client’s available funds.

A number of road segments and key intersections were identified as requiring upgrades to facilitate haul truck movements which included both TMR and local council roads. The development of treatment options to address or mitigate identified deficiencies and issues, including development of concept layouts and intersection treatments catering for swept turn paths of design vehicles were prepared.

HIG liaised with both stakeholders and road authorities to determine a basis of design and standards to which the upgrades needed to meet.

The final project delivery included the preparation of detailed designs and estimates and preparation of contract documentation.

HIG are also providing construction supervision and contract administration for the construction phase of the project.