Sydney Fish Markets – Demolition

This project involved the early works demolition of Blackwattle Bay Wharf, a complex operation that required the removal of over 500 piles, including 400 timber piles and 100 concrete piles. The extraction process was influenced by the site-specific conditions and existing geotechnical challenges, necessitating the development of two specialised extraction methods to ensure the safe and efficient removal of the piles from the seabed.

Given the complexity of the site, one of the proposed methods for pile removal involved the application of a 50-ton vertical line pull. This method utilised a 50-tonne hydraulic A-frame to generate the necessary force to vibrate the piles out of the seabed, ensuring controlled and safe removal of each pile. This technique was particularly effective for extracting piles that were firmly embedded in the ground.

The second method, known as the cookie cutter method, involved the fabrication of specialised cookie cutter piles designed to be used for vibrating existing piles. These custom-designed piles were placed around the base of the existing piles to destroy soil cohesion, reducing the friction between the pile and surrounding soil. This process allowed for easier vibratory extraction, which significantly enhanced the efficiency of removing piles that had become difficult to extract using traditional methods.

Both methods were chosen after careful consideration of the geotechnical conditions and site-specific challenges, ensuring that the demolition process was conducted safely and with minimal disruption to the surrounding environment. The use of these innovative extraction techniques enabled the team to complete the pile removal efficiently, setting the stage for further phases of the demolition and redevelopment of Blackwattle Bay Wharf.