Jet Grouting within Contaminated Land Fill

The site of the Barangaroo Project forms part of an old Sydney Gas Works and is heavily contaminated with hazardous materials. A perimeter retention wall is to be created with minimum UCS strengths of 5 MPa. Construction of this wall involves overlapping jet-grouting columns, performed within negative pressurised tents with all personnel subjected to fully enclosed hazardous PPE and controlled decontamination procedures. Two fluid jet grouting was considered to be of high risk to personnel due to creating a high level of airborne contaminates within the tent. Single fluid jet grouting utilising a patented optimized monitor enabled the construction of columns up to 1.8 m in diameter in typical sandy clays and coal tars. This paper describes the jet grouting works with focus on hydration of slag base cements within coal tar environments, environmental protection procedures, contamination controls and there overall effectiveness, as well as specific spoil management.