ABSTRACT
The design criteria and basis or series of assumptions that are to be adopted for the design should be documented as per good industry practice at the start of the rock tunnel design stage. Some of the design criteria and basis of assumptions may be mandated by the client or national engineering and safety regulations and should therefore be strictly adopted. The majority of the operational design requirements address safety practice and requirements to be incorporated into any public use tunnel design and include ventilation, lighting, communications, emergency escape or refuges, safety bays, and fire suppression systems. The constructability assessments should confirm that the design is technically feasible for construction by utilizing currently available and proven technologies in the underground industry. The design of rock tunnels should not rely upon unprecedented construction approaches that introduce risks of cost and schedule overruns.
