The project includes the construction of a 4,455-metre track slew, four new culverts and the relocation of three existing signals.
BG&E prepared design documentation for the construction contract for the section of rail track exhibiting long-term formation failure due to poor soils. The design included the rail alignment, earthworks and drainage crossings for two segments of track rehabilitation and a 3.6-kilometre track slew. The track slew was designed as an offline construction to the existing main line.
Our team also worked with the geotechnical consultant to complete formation design, address safety and project environmental risks for construction, including formation slope stability assessment where excavation works were parallel to poorly performing highly reactive clay soils. BG&E also addressed flooding concerns for the project and worked with signalling consultants to optimise the design to minimise signalling impacts.
The key aspects of the structural design included pre-cast uniform (four-sided), box culvert design for 350LA railway loading, associated headwalls, handrails and elevated stair/platforms for drainage crossings.
The civil design considered optimisation of horizontal and vertical alignment of rail design to address constructability, staging, cover requirements for the drainage culverts and to minimise earthworks/pavement volumes.
Part of BG&E’s scope of works also included undertaking waterways investigation to determine the performance of the existing culverts and to perform comparisons for proposed drainage structures and the long-term performance during design storm events.
Some of the key constraints included constructability and staging, addressing off-line construction of the drainage culverts adjacent the existing mainline. Constructability and staging were considered for the project slew start and end points, which required optimisation of the alignment and earthworks.