Founded in 1819 by Thomas Jefferson in Charlottesville, Virginia, the University of Virginia (UVA) supports more than 550 buildings that amount to a total of 16 million gross square feet. In 1895, the first of a series of utility tunnels was created to service the buildings located on the campus, known as the Grounds, and now span approximately four miles. The walk-thru tunnels vary in size and carry multiple utilities, including steam, pumped condensate, medium temperature hot water, low temperature hot water, potable water, fire water, telecom, and electrical.

Reassessing the UVA's Utility Tunnels

Over the years, there have been numerous repairs and upgrades to utilities housed in the tunnels, but the tunnels themselves are the original 1950s and 60s construction. An emergency situation in 2008 required the repair of a tunnel under one of the busiest intersections on the university grounds. As a result, UVA decided to update the tunnel conditions assessment report to find the areas of the tunnels with the highest structural concern. We were hired to make those assessments for the University.

We inspected approximately one mile of tunnel that was thought to require immediate attention. Our assessment included a detailed description of structural issues, recommendations for improvements, probable construction costs, and a recommended improvement period.

Reinforcing UVA's Utility Tunnels

Since our updated assessments in 2008, we have designed repairs for a half-mile of tunnels, making them more structurally sound. To strengthen the tunnels, we used the encapsulation method, digging down near the existing wall and forming a new wall to reinforce and protect the older structure. Complicating this approach was the fact that the tunnel top also served as a sidewalk. As a result, the tunnel top had to be removed and a new stronger slab poured back in its place. Pouring over top the old slab was not possible due to impacts with existing grade, drainage, site stairs, and building entrances. The top slab was required to support heavy vehicular loads since the tunnel top provides the only means of access for emergency vehicles and fire equipment to portions of the Academical Village, a UNESCO World Heritage Site.

While students were on break for the past two summers, we worked with UVA's Facilities Planning and Construction department and the contractor to expedite the construction process. This close collaboration allowed the team to meet a short 90-day construction schedule in time for the students' return for the fall semester. The completion date was maintained while working around several events, such as graduation and alumni weekend, along with the discovery of an active unmarked fiber optic cable and a historical stone wall during excavation.

"Dewberry has been very supportive through the entire tunnel design and construction process," said William Moore, senior project manager of University of Virginia's Facilities Planning and Construction. "In particular, the demanding construction schedule required immediate [request for information] response for the multiple underground obstructions encountered. The communications were timely and articulate assuring completion on time and within budget."

Helping Prepare for Future Maintenance and Growth

To avoid future emergency situations, Dewberry has been asked to conduct evaluations of the remaining tunnels, proposing upgrades to areas where the need is pressing. We continue to monitor other tunnel segments to make sure they are safe and functional as well. Our goal is to ensure that the utility tunnels are safe for UVA employees, provide reliable distribution of central utilities to students, and provide ample room for future growth.