Rio Tinto Iron Ore 2 Mile Culvert Replacement

Design and Analysis (D&A) was commissioned by ADR Projects to provide comprehensive engineering design support for the replacement of a failed culvert at Rio Tinto's 2 Mile Rail Yard near Karratha, Western Australia. The project was initiated following structural collapse during Cyclone Sean in early 2025, which compromised a critical drainage culvert beneath an operational rail line.

D&A's scope included geotechnical investigations; civil, geotechnical and structural design of the replacement works; development of a standardised culvert replacement process; review of the flowable fill mix design; and provision of construction phase support services. The preferred approach was selected by Rio Tinto due to its durability, ease of placement, compatibility with Rio Tinto's earthworks and drainage specifications, and ability to be constructed within the available track possession window.

The design incorporated staged placement of flowable fill in multiple lifts, with specific dunnage requirements to mitigate flotation risks. Extensive testing of mix designs was undertaken to verify early strength development, enabling safe loading and efficient construction within a constrained possession period. D&A's design and construction methodology supported the achievement of project objectives while maintaining safe operations and minimising disruption to rail activities.

This project highlights D&A's expertise in rail infrastructure design, culvert engineering, flowable fill analysis, and geotechnical risk management. The successful delivery of the works demonstrates D&A's commitment to providing practical, compliant and constructible engineering solutions for major resource sector clients across Western Australia.