Advances in tunneling technology is theme of seventh Cutting Edge conference

Repairing and replacing the nation’s aging and crumbling infrastructure has become a major issue with the American public. It is no secret that the upkeep of roads, tunnels, bridges, and water and waste water facilities has been neglected for decades. Cities, states and towns across the United States are now grappling with these issues, ones that will take decades and billions of dollars to fix.

Because of this infrastructure issue, the North American tunneling industry is flourishing. Cities across the country are looking to go underground to alleviate traffic issues, transporting water and waste water to more people in more efficient ways.

In October, the seventh annual Cutting Edge conference was held in Atlanta, GA. Put on by the Underground Construction Association of SME and Britain’s Tunnelling Journal, about 175 tunneling and underground construction professionals from around the world attended. Attendees included owners, designers and contractors. An accompanying exhibit included 28 companies.

The theme of the two-day conference was Advances in Tunneling Technology. Speakers examined the latest advances in tunneling technology, its methodology and how these advances can be harnessed to assist upcoming major tunneling projects. The conference featured a tailored, high-end, single-track program of subject-specific presentations that focused on innovation and practical experience. Two in-depth panel discussions at the end of each day were also included.

Patricia Mulroy was a keynote speaker on Monday. She is senior fellow for climate adaptation and environmental policy at The Brookings Institution. Like many others, Mulroy believes the U.S. infrastructure in in a state of disrepair. But, she said, no one wants to talk about it. “We need to have a conversation about infrastructure. We cannot be afraid to talk about building it and the cost.” For this to happen, though, the nation needs leadership.

Mulroy said that climate change — she is a believer — will have a significant effect on water storage in the United States if governments don’t act now. She said the issue of water storage and climate change has become politicized and no one wants to tackle the problem. “We have regulatory paralysis,” she said. When trying to permit a water project, there many groups that interject themselves into the process, mostly through the courts, and the permitting process gets dragged out.

The administrative and regulatory system needs to be fixed, Mulroy said. Building a 21st-century water system is going to be a daunting task, she said, but it must be done. Nothing, she said, affects water storage like climate change. So, in order for the nation to keep up with its water needs and ensure there is enough for future generations, governments must act now.

A panel discussion on Monday, scheduled for an hour-and- a-half but could have easily gone on for two, addressed the subject of alternative procurement models for the tunneling and underground construction industry. Randy Essex, of Mott MacDonald, chaired the session. He began things with a few questions for the panelists and the audience: How do we allow owners to maintain control and still encourage innovation from contractors? And, what goal do we seek when we talk about alternative procurement models?

“Contractors do not know what they are getting into until they get into it,” said Mike Roach, of Traylor Bros. and current UCA of SME executive committee chair. “The definition of design-build means something different to different people, particularly contractors and designers. Not understanding or completely knowing what is in a contract makes it difficult for those involved in a project. More certainty in a contract would allow contractors and designers to be more innovative,” he said.

Greg Colzani, of Jacobs, said collaboration is the key word in any contract. He said that owners want earlier project involvement from contractors. But what is in it for the contractor? Are there hidden risks for the contractor? And, is there equal benefit for the owners and contractors?

Technical sessions

The single-track conference features several technical presentations from authors from around the world. Monday morning started with the session The Challenges of Subaqueous Tunneling. This session looked at the challenges of subaqueous tunneling and the approaches that are being developed to deliver these complex projects. Projects discussed included the Chesapeake Bay Bridge and Tunnel Districts Parallel Thimble Shoal Tunnel, VDOT’s I-64 Hampton Roads Bridge-Tunnel Expansion and Toronto’s Ashbridges Bay Treatment Plant Outfall.

Next up was the Advances in Contract Delivery session. This session focused on alternative forms of contract delivery, such as Construction Manager at Risk, progressive design-build and early contractor involvement. Key industry figures and project owners also discussed issues surrounding financing and the sharing of risk.

The Advances in Materials, Equipment and Linings session looked at recent advances and novel applications of tunneling materials, equipment and linings. These included innovation in precast segment connections and corrosion protection for linings, and advancements in grouting techniques and TBM grouting systems.

The UCA of SME Young Members Committee prepared a session called New Ideas and Faces. Speakers in this session provided insight into innovative uses of underground space, emerging tunneling trends and technology, new techniques for renovation, uses of underground space and new developments in digital technology and three-dimensional imaging.

The Advancements in Excavation Technology examined the challenges of going faster and rapid excavation techniques. The session included presentations from The Robbins Co. and Herrenknecht and discussed approaches and innovations that are being developed to deliver complex projects safely and efficiently.