Major Projects

Hay Point Expansion Stage 3

Client:

McConnell Dowell Geosea JV

Services Provided:

Driveability Analysis,
Temporary Works Design and Optioneering,
Design Review and Performance Assessment,
Dynamic Pile Testing, Static Pile Testing.

Project Brief

The Port of Hay Point, south of Mackay comprises two adjacent coal handling facilities. Stage 3 expansion works involved construction of a new 1.8km loading trestle and a third wharf berth. FSG was involved throughout the tender and delivery phase providing both design, constructability assessment and testing services.

Site Geology & Challenges

The geology of the site generally comprises alluvial deposits in the form of sand and clay over bedrock. Bedrock consists mainly of Tuff but also shows areas of sandstone, siltstone and mudstone. Tuff is a compacted and lithified volcanic ash which increases in strength with depth, the uppermost layers being weathered to highly weathered. Very shallow pile penetrations, often directly into bedrock meant that monitoring of driving stresses and assessment of available tension capacity was of critical importance.

Scope of Work

FSG were engaged by McConnell Dowell to provide driveability analyses for all sections of the project as well as design and constructability advice in relation to temporary and permanent works design. Tension capacity governed for a large proportion of piles so a clear understanding of tension capacities, including a detailed and realistic assessment of cone pull-out resistance, was essential.

In order to minimise the reliance on tension anchors and thereby expedite the works, FSG adopted an innovative and realistic approach to assessing tension capacities by addressing a number of different cone pull out failure mechanisms, as well as evaluating pile shaft resistance.

Following the commencement of the works, FSG supplied 3 No. PDA testing kits and provided on site PDA training for 25no. site engineers and management personnel. Once training was complete, testing was carried out remotely across multiple work fronts utilising JV field staff and FSG testing staff logging in remotely.

FSG were also engaged to conduct planning and monitoring works for 10no. offshore static load tests. In a world first, each test was monitored simultaneously using an innovative arrangement of dial gauges, strain gauges and PDM, which enabled the collection of high accuracy load-deflection data without the need for a fixed reference frame.

Conclusion

FSG’s driveability analyses allowed our client to effectively plan the works and procure hammer and pile sizes to suit individual work fronts.

Design review and optioneering for temporary works assisted in overcoming key project risks, and enabled successful execution of the preferred construction methodology.

FSG’s state-of-the-art approach to estimation of pile tension capacities and cone pull out failure modes allowed, design optimisation and enabled the number of tension anchors to be reviewed.

FSG worked with a range of project staff across multiple work fronts to ensure PDA testing was carried out seamlessly without delay to the works. During static load testing in the marine environment, FSG were able to remotely monitor pile movements. This was the first time that this approach has been used and has numerous applications in heavy duty offshore foundations (such as marine wind farm tower bases).