The scope of the project was to install one 14-tonne 110kL underground storage tank at a 5-metre invert, and one 4-tonne 20 000 kL separator tank at a 3.5-metre invert, inclusive of anchor system and tank bed preparation.
Complications: Excavation batter intersected with site boundary and water table. Reduced access to three sides of excavation.
Involved engineered solution: Grout injection to protect the neighbouring property’s concrete wall panels. Excavated to accommodate the installation of dewatering spears, and pumping equipment.
Back fill in 300mm lifts and compacted appropriate material to ensure a 98% compaction.