When work on the latest expansion to Washington, D.C.’s Dulles Airport is completed in 2020, residents of the nation’s capital will see a vastly different landscape than they are accustomed to. Not only will the Washington Metropolitan Area Transit Authority (WMATA), locally known as the Metro, decrease traffic with regular service to Dulles Airport, but the area will see the completion of new transit stations, and perhaps more importantly, an end to five decades of construction on the project. The Metro is one of many tunneling projects underway in the United States, and one of many discussed when some of the world’s top experts in subway and other tunnel and underground construction came together for the 2018 North American Tunneling Conference at the Wardman Park Hotel in Washington, D.C. June 24-27 to talk about all things tunnel related. A record 1,115 people attended the three-day conference that featured 145 exhibitors in 175 booths and 20 technical sessions that covered all aspects of tunneling and underground construction.
The conference kicked off with a keynote presentation from Christine Merdon, deputy architect and chief operating officer of the Architect of the Capitol. Merdon spoke on the topic of managing a mega project, something that resonated with many in the room. Merdon oversees the overall direction, operation and management of the Architect of the Capitol (AOC). In 2016, Merdon and her team of employees completed extensive renovations on the U.S. Capitol. It was a threeyear, $60-million dollar project that repaired more than 1,300 cracks and deficiencies in the 150-year-old cast iron dome, which is the largest dome in the world. The project also included a new coat of paint on the interior of the building for just the fifth time ever. Like tunnel projects that pass beneath high-rise buildings, or buildings of historical and cultural significance, the Capitol renovations had extra pressure to do things right without creating any damage to neighboring areas.
Merdon laid out her management philosophy, explaining the importance of keeping employees and the public informed of the project updates. She pointed out how the project engaged in social media campaigns to control the message and how they used the platforms to celebrate milestones, which helped employees and the public feel more connected to the project.
Merdon noted that, “if you don’t tell your own story, someone else will, and it’s not always the story you want told.”
Although not always as visible as repairing one of the most significant buildings in the world, tunnel projects around the world often face similar scrutiny as did the Capital Restoration project. The work often requires some sort of disruption to street traffic or stoppages of existing service and is often done beneath densely populated areas.
One such project is New York’s Second Ave. Subway project, a $4.5-billion project. The new subway line on the east side of Manhattan opened Jan. 1, 2017 on time while maintaining the budget for the project. Michael Trabold, of AECOM, spoke about how the project team utilized different strategies during the project and how the success was only achieved through all of the parties working together.
From the opposite side of the United States, Jason Choi of WSP USA spoke about the challenges of not just passing below the city of Los Angeles but constructing new transit tunnels beneath the existing tunnels.
It was one of many presentations from the west coast of the United States, which has experienced an impressive amount of tunneling projects in recent years. From the SR-99 project in Seattle, WA to the proposed California WaterFix project, many of these projects were discussed by experts. One such project is the Crenshaw/LAX Light Rail Transit Corridor Project, a three-year project to add cross passages to the corridor.
From Chicago, IL, Miquel Sanchez spoke about Chicago’s Tunnel and Reservoir Plan (TARP), a nearly $4-billion program that has lasted more than 30 years and has created, possibly, the largest and longest combined sewer tunnel and reservoir system in the world. The now-completed tunnel system consists of a 10-m (33-ft) finished diameter and 490-m (1,600-ft) long hard-rock tunnel constructed from a 27.5-m (90-ft) diameter and 92-m (300-ft) deep main gate shaft. The gate shaft houses six, high-head 4.4 m x 9 m (14.5 ft x 29.5 ft) wheel gates installed in the bifurcated and steel lined section of the tunnel. The tunnel also includes portal and energy dissipation structures as it daylights into the reservoir.
There were also presentations from projects outside of North America including a paper by Fabio Pellegrini, Brendan Daly, Andreea Enescu and Nicolas Swetchine who wrote about sustainable infrastructure tunneling as it applied to the Gotthard Base Tunnel Project and the sustainable reuse of aggregates mines from the tunnel.
Because underground construction generates large volumes of spoil materials and consumes large volumes of natural resources, many infrastructure projects are negatively perceived by the public. To address these perception issues, tunnel owners and developers evaluated the various options for beneficially reusing excavated material to reduce local impacts and advance environmental stewardship through sustainable construction materials solutions. These sustainable construction solutions not only save money and the environment, but also promote a positive community perception for local development.
Another interesting presentation was from Pricilla Nelson of the Colorado School of Mines, who spoke about the need to conduct an appropriate framework and metrics for infrastructure analysis that can include complex systems representations for all sectors — physical, social and environmental. Nelson was also recognized by the UCA of SME as the Outstanding Educator during the awards dinner and banquet. Harvey Parker received the Lifetime Achievement Award and the Outstanding Individual Award was given to David Klug.
The UCA of SME also recognized the Northern Boulevard Crossing as the Project of the Year during the awards dinner.
A pair of short courses, Design and Manufacturing of Precast Segments and Grouting Used in Underground Construction and Tunneling kicked off the week, which concluded with three field trips.
UCA of SME, along with Tunneling Journal, will host the seventh annual Cutting Edge Conference Oct. 29-31 at Loewes Atlanta Hotel, Atlanta, GA. UCA of SME will then return to New York City for the annual George A. Fox Conference on Jan. 23 at CUNY Graduate Center. The UCA of SME will host RETC, June 16-19 in Chicago, IL.