Devonport Berth 3

Project aim

The aim of the project was to upgrade the berthing facilities at Devonport Berth 3 to cater for the new larger Spirit of Tasmania Ferries. 

What we did

pitt&sherry’s involvement for the Berth 3 upgrade included:

• Geotechnical investigations and design
• Dredging geotechnical Design
• Scour protection geotechnical inputs and design
• WSCAM inspections of the existing wharf
• Wharf Piling Design
• Reclamation design and documentation
• Seawall design using rock bund fill
• Material re-use assessment
• Rippability assessment
• Services design and documentation
• Facilitation of Safety in Design workshops and provision of Safe Design report
• Construction Impact Assessments including vibration monitoring during pile driving
• BIM documentation of services
• Design and documentation of the temporary reclamation stockpile testing and dewatering arrangement; and
• Design and documentation of the long term reclamation stockpile; and
• Construction Certification.

The geotechnical investigations were undertaken to supplement existing data, including overwater seismic refraction survey, rotary borehole drilling and CPT testing.  An interpretative geotechnical report was prepared for the wharf and reclamation design.

The reclamation was designed to be undertaken over soft soils with pitt&sherry’s contribution including the selection of fill materials, settlement assessment and bearing capacity assessment to reduce the risk of mud waves.  For the bund wall we carried out a stability assessment, design of dredging requirements, assessment of scour potential of soils and weathered rock at bund foundation level to limit the extent of the outer berm scour protection bund.  We also designed the filter materials and geotextiles to prevent piping and fines removal through reclamation rock spalls.  Documentation was prepared for all aspects of the reclamation and bund wall design and verification of settlement monitoring data was undertaken to allow handover to the Client.

In addition to the reclamation design, pitt&sherry also carried out the geotechnical design of the dredging profile along the main wharf frontage to suit the final revetment requirements.  The design included short term and long term conditions including ground improvement for provision of a 200 tonne crane working within 2m of the edge during construction.  

pitt&sherry carried out the geotechnical design of the new wharf profile foundation for lateral and vertical loads, liquefaction assessment, and prepared the construction methodology for pile verification including the pile testing regime.  

pitt&sherry facilitated a number of Safety in Design (SiD) workshops for the upgrade works to identify potential hazards and controls to ensure a safe design for all phases of the project. The outcome was a written safety report for the client in accordance with Work Health and Safety Act (2012) and Regulations (2022).

The scope of services for pitt&sherry included the geotechnical design of piled land based mooring points, for the new wharf and design of a strong point to strengthen the existing Wharf 3. This included the assessment of historic records for existing piling and geotechnical data, to establish ground models and pile capacities for the existing wharf.  The design services for pitt&sherry also included vibration during pile driving and the impact on existing wharf structure.  

During construction we reviewed the pile driving sets and the dynamic and load test results for final acceptance of the piles. 

Outcomes

The project has resulted in the provision of wharf infrastructure for the Spirit of Tasmania IV & V ships which will be 212m in length and 48,000 tonnes.