Abrasiveness of Hawkesbury Sandstone (Sydney Harbour tunnel dredging) 68
This chapter discusses the tool consumption data of a rock cutting dredging operation. It explores the excavation of the trench for the Sydney Harbour Tunnel, which was partially cut in rock. The chapter presents the data available on the excavation projects and on the rock properties. It examines the proposition of using rock strength index tests and petrography instead of, or in conjunction with, laboratory cutting and abrasion tests. For two projects carried out in the Sydney region, the Sydney Harbour Tunnel and the Sydney Ocean Outfall tunnels, considerable attention has been paid to the abrasiveness of the Hawkesbury Sandstone. For both projects results of the core cutting and abrasion test developed by F. F. Roxborough were available. The tests were performed in the Laboratory of the Department of Mining Engineering of the University of New South Wales, where Professor Roxborough has set up the apparatus for the cuttability assessment tests.