Rock tunneling is a specialty that is incorporated across all of our market sectors, including transportation, roads and highways, rail and transit systems, water and wastewater conveyance, power and energy, and underground storage facilities, including petroleum and nuclear waste repositories.
Our engineers have extensive experience in all aspects of rock tunneling and mined cavern projects, from conception and feasibility studies, to detailed design and construction, as well as the operation and rehabilitation of the facilities throughout their life cycle. We have been involved in rock tunnel design in major cities the world over, including most major underground transit systems in the United States.
WSP adapts traditional design and construction techniques to specific site situations, and developing innovative techniques and approaches for projects that demand solutions beyond standard practice. We have experience across various geological settings on all six continents. We anticipate complications that could arise during construction and account for them during the preparation of design and construction documents, as well as during construction.
Drill and Blast
Drill and blast is an excavation method used frequently in hard-rock tunneling because its flexibility allows for different layout setups. WSP has used drill and blast to build tunnels with diameters up to 30m wide, mostly supported by steel bolts and fiber-reinforced shotcrete (sprayed concrete). We use controlled blasting techniques in our design to control over-break, reduce vibration and aid the stability of the remaining rock formation. When vibrations or a damage zone in the rock is not feasible, the method can be supplemented with wire sawing. In these cases, a wire is fed through drilled holes and drawn along the actual surface without causing vibrations. One major project recently completed using drill and blast technique was the Stigbergsgaraget parking garage in Stockholm, a finalist in the 2016 ITA Tunnel Awards.