Ground Improvement Over Landfill for the Barton Park Recreational Precinct

This paper describes the selection, design, and execution of ground improvement to treat an old landfill site on which the Barton Park Recreational Precinct will be constructed. Barton Park encompasses an area of 19 ha, and is located over an old landfill that operated between 1940 and 1970. On this site, the St. George Football Stadium was constructed in 1976. By the 1980s, the stadium had become derelict and disused. In 2022, Bayside Council successfully applied for funding from the NSW Government’s Accelerated Infrastructure Fund that will go toward a major upgrade of the Barton Park project. The Barton Park project will provide a community recreation precinct including three full-size grass soccer fields, four tennis courts, two multipurpose courts, a cycleway and connecting walkways suitable for walking circuits as well as four change rooms with showers and toilets. The landfill underlying Barton Park extends to a depth of up to 9 m. Due to this there were serious concerns regarding post-construction settlements and differential settlements. A number of ground improvement options were considered, including the use of Rigid Inclusions, Dynamic Compaction, High Energy Impact Rolling and Geocells. After a program of laboratory testing, detailed assessment of potential settlement and rate of settlement; consideration of relative merits, risks, and cost; and a suitable combination of piling the stadium structures, impact rolling, and use of geogrids in areas more sensitive to differential settlements were adopted. The investigation program, assessment, and design of the ground improvement are presented in this paper.