Liquefaction susceptibility and global stability (lateral spread)
The site is underlain by sandy reclamation fill overlying marine and alluvial deposits with liquefaction susceptibility.

Pavement design
Low strength, completely saturated subgrade conditions are present at the pavement design level. The marine travel lift has 370t wheelset loadings with peak wheel pressures of 1 MPa (approximately twice the wheel load of a fully loaded A380 Aircraft).

With targeted geotechnical investigation, and detailed liquefaction analyses we were able to demonstrate that liquefaction related effects could be largely controlled or mitigated. The length of strengthened seawall and new length of seawall has been designed to adequately mitigate the risk of global instability or lateral spread following a seismic event.
.

Specialised, supplementary geotechnical investigations and analyses were undertaken to deliver a significantly refined pavement design resulting in a 50% reduction in pavement thickness and reduced excavation depth. Ex-situ stabilisation of highly contaminated soils was undertaken in lieu of exporting materials to a licensed landfill and importing quarry grade subbase and basecourse materials. The subgrade improvement works are approximately 70% complete and validation testing has confirmed it is meeting or exceeding required design criteria