BSP hammers drive steel piles for Port of Brisbane wharf extension
Foundation work for the extension to Wharf 10 at the Port of Brisbane in Queensland, is the latest piling project in Australia being undertaken by Albem Pty Ltd with the help of two BSP International Foundations heavy-duty hydraulic piling hammers.
To drive the 330 vertical and 31 raking piles required to support the extension to the existing 372-metre long container wharf, the Brisbane-based civil engineering contractor is using a new generation CG210 hammer to install the vertical piles and an older HH1146 hammer to drive the raking piles. Both hammers were supplied by Steelcom, BSP’s dealer for Australia and New Zealand, to achieve compression capacities ranging from 5000kN to 7000kN.
Albem’s decision to purchase the CG210 and hire the HH1146 for the Port of Brisbane project was based on Steelcom’s dependable service and the versatility and proven performance of the CG and HH hammers in differing applications and ground conditions. Based in Sydney, New South Wales, Steelcom was set up in 1983 as a supplier of sheet piles and a wide range of piling equipment to the foundation industry in Australia, New Zealand and the Pacific Islands.
The piling grid for the extension structure comprises 66 rows of piles with five piles in each row. Each pile is fabricated from 18m long standard pile tube with wall thicknesses ranging from 12mm to 16mm and welded in sections to the 45m long pitched length. Three pile diameters are being used: 1200mm, 1050mm and 900mm depending on the capacity required for each row. Pile sets range between approximately 2.5mm and 13mm, with drop heights of 1200mm to 1400mm again depending on the capacity for each pile grid.
The pile tube and pile driving contributes around 35% of the total cost of the wharf construction and represents the highest risk for both the client and the contractor.
Equipped with a 14-tonne ram weight, the CG210 hammer is based on BSP’s heavy-duty CG range of three models offering ram weights of 12, 14, 16 and 20 tonnes and with maximum energies per blow extending from 180kNm up to 300kNm. Like all the CG models the CG210 is designed to operate in crane suspension mode or from piling leaders and can accommodate piles up to two metres in diameter with a standard pile skirt and drive cap.
A major feature of BSP piling hammers is their high efficiency, achieved by the actuator design allowing the hammer drop weight to fall under gravity with virtually no resistance from the hydraulic circuit. The simplicity of the actuator design enhances the operating efficiency because of fewer moving parts and all the hydraulic components closely coupled to the lifting cylinder. This feature provides the contractor with high output performance and above average fuel efficiency from the power source.
Interestingly, the contractor Albem is driving the piles using an innovative incrementally launched piling frame supported on the previously driven piles and configured for the five grids of piles. The rig is set up to suit the pile sizes and can be pushed forward to suit the varying bent spacing. A separate frame is moved progressively by a crane and is also supported on previously driven piles to undertake the raking piles intermittently spaced along the wharf structure.
To confirm that piles are driven to the required capacity of the design criteria Pile Dynamic Analysis (PDA) testing is undertaken on a percentage of the piles. From the initial test, acceptance criteria is developed for the subsequent piles, with conformation of these criteria by the next PDA test. As with all foundations, constant monitoring of the piling progress is required to access the expected ground conditions with the real conditions. This is done by analysing the driven pile toe levels and driving sets.
Albem has achieved excellent results with the CG210 hammer enabling the company to keep ahead of the construction programme. Driving of the vertical piles was completed in March this year but installation of the raking piles may take the finishing date of the piling contract towards the end of the year. The wharf construction is expected to be completed in the first half of 2008.
A purpose-built port, the Port of Brisbane is the third largest and fastest growing container port in Australia. Facilities extend up the Brisbane River for about 15 kilometers and include bulk commodity and general cargo wharves, a cruise terminal and a dockyard. Each year over 2,600 ships exchange around 26 million tonnes of cargo. This activity generates a total annual contribution to the Queensland economy of $A770 million.
-- ENDS --