Mount Gibson Iron: Koolan resurrected
CONFIDENCE in the integrity and safety of the new seawall design for Koolan Island was crucial to ensure a collapse would not happen again, according to Mount Gibson Iron chief executive Peter Kerr. “The new design has a higher factor of safety and is fundamentally different to the original seawall, incorporating an impermeable cement-bentonite seepage barrier within the embankment,” he said. “This in-ground barrier, which is more than 430m long, 1.2m thick, and extends down to bedrock (over 40m at its deepest point), was installed by a specialist contractor (Keller) and protects the pit from tidal water flows, ensuring the structural integrity of the seawall embankment. “The structure also incorporates extensive monitoring instrumentation, including more than 150 sensors that enable…