Hard Rock Tunnelling Techniques

Study Notes

Hard Rock Tunnelling

Drill and blast tunnelling technology is introduced.
A tunnel is defined as a completely enclosed underground passageway, usually with openings for entry and exit at each end.
The rock mass is the construction material and site.
Various methods of tunnel excavation are discussed, including drill and blast, boring (TBM), and cutting (roadheader).
Different tunnel sections (horseshoe, D-shaped, circular, rectangular) are presented.
Deep lake taps (105m, 109m, 120m, and 170m) for various hydropower projects are described.
Troll shore approach, involving gas pipelines from the North Sea being pierced under the water, is detailed.
Diagrams show sequential excavation methods for large caverns and geological features.
Additional rock support methods (forepoling, concrete lining, pre-grouting, and ground freezing) are mentioned.
Equipment used for different tunnel excavation methods (rubber-tyred equipment, railbound equipment, drill rigs, haggloaders, front-loaders, rock dumpers, and LHD loaders) is showcased.
Diagrams and examples illustrate direct loading and various other tunnel excavation techniques employed in different contexts.
The diagrams detail the sequence for different types of excavation methods like Drill and Blast or excavation by the use of tunnel boring machines (TBM).
The "Round Cycle" for this type of excavation is described with a step-by-step approach involving drilling, charging, firing, ventilation, scaling and rock support, loading and transport, and control and surveying.
Future uses for tunnels, illustrated by an example of underground city development in Singapore, are shown.