Overcoming Challenges with Jet Grouting at Sydney International Airport

Abstract

The Runway End Safety Area (RESA) is an extension to the end of one of Sydney International Airport's runways. As this Area passes through or close to a number of already existing facilities it has had to be bridged over a heritage listed sewer, an airport perimeter road and a highway road. RESA was previously low lying farming land, man-made filling from earlier dredging works and predominantly marine originated alluvium with a high groundwater level. The loads generated by bridging RESA over existing structures and lowering the road level at the intersection with RESA has required the application of special geotechnical methods. Jet Grouting was used in RESA for multiple purposes such as increasing the ground's bearing, retaining the ground and creating impermeable barriers to cut off the flow of water during construction in difficult ground conditions, obstructions, height limitations and specific airport regulations. Multiple requirements and variations in ground conditions required detailed design for numerous cases and stages of the work using finite element calculations. Quality control, testing and monitoring was able to demonstrate the successful application of jet grouting in this complicated project.