Our design engineers incorporate sophisticated analysis and design methods for large underground caverns, mines, and other usable subterranean space.
Pedestrian Tunnel Design
An all-weather connection downtown was critical to the long-term growth of the convention and visitors' industry.
This project consisted of designing an underground tunnel and skyway from one building to another where it enters an existing downtown skyway system.
CNA’s technical leadership was needed to deal with the wide range of geotechnical engineering, architectural, risk-assessment, and utility conflict issues.
​
.jpg)
Underground
Space
Deep Underground Laboratory I
The cavern was excavated 2341 feet below surface to create a 23,000 cubic yard cavern, plus connecting tunnels.​ CNA was responsible for feasibility study, site selection and investigation, space planning, design, and construction services. The scope of the project required CNA it integrate and coordinate all disciplines including civil, geotechnical, mechanical, electrical, risk-assessment and environmental to maximize efficiency of space and provide experimental functionality.
Mined Underground Storage Space
​This project consisted of two storage caverns, a 4-story conventional surface building, two vertical shafts, and a mined portal entrance. The mined caverns and tunnels have a footprint of 106,000 square feet and an excavated volume of 95,000 cubic yards. The 50-foot-high mined portal provides a drive-in entrance for large vehicles.
CNA provided the following services for the mined space, shafts, and portal structure: feasibility study, preliminary and final design, construction engineering and administration.
Sanford Underground Laboratory
​
CNA was the lead designer of the excavation and outfitting for the Davis Campus, located 4850 ft below the surface at the Sanford Underground Laboratory at Homestake in Lead, South Dakota. The Davis Campus houses high level physics research.
The project required rock excavation, re-support of the Davis cavern, structural steel deck, a water tank, concrete and shotcrete installation, mechanical/electrical systems, deep shaft review and modification, and fire and life safety provisions.
The 49-foot wide Transition Cavern is supported with cable rockbolts, resin grouted rockbolts, and shotcrete. The existing Davis Cavern and connecting tunnels required similar support.
CNA provided the following engineering services: design team management, cost estimating, rock excavation design and specifications, structural steel deck design, Project Manual preparation for multiple contracts, and construction engineering services.
​