A new vertical shaft has been proposed to connect surface to existing workings at a depth of 1000m below ground. The shaft is to be a mineral hoisting shaft with the ability to act as an emergency egress and has a proposed circular shape of 6m diameter. The stratigraphy of the geological strata at the shaft site is as follows:
Depth from surface Strata type
0-20m Soil/overburden
20-100m Weak regolith
100-300m Siltstone of moderate strength low water flow
300-400m Impermeable shale of moderate strength
400-800m Bunter sandstone of high strength, aquifer, high water flow
800-1000m Shales, medium strength, low water flow
The purpose of the exercise is for students to develop a shaft sinking and lining strategy for the site. The expectation is for students to compile a report of their findings, the report should include:
1. Proposed excavation strategies
2. Timelines/project management for the project
3. Equipment and consumables used
4. Costing’s ( a useful source is the AusIMM monograph ‘Cost estimation handbook’)
5. lining design
6. sinking stage design
7. shaft fittings
and any other salient points.
Note: students should list any assumptions made.