Students Design New York City Tunnel at Stevens Institute of Technology

Hoboken, NJ, April 30, 2011 --(PR.com)-- Civil Engineering students at Stevens Institute of Technology are working on the design of a section of the East Side access tunnel which will bring more Long Island Rail Road trains into New York City. The Senior Design team of Reed Cummings, Leonid Katsman, Matthew Lawson, and Dylan Lupo has assessed and designed a 120-foot tunnel that will run under Northern Boulevard for the East Side Access public works project in New York City. The team is advised by Associate Professor of Civil Engineering Leslie Brunell and sponsored by Schiavone Construction.

"This is a very complex project with numerous structures above the proposed tunnel and water surrounding the area," says Dr. Brunell, "the experience of working on a real life project with so many constraints has really shown this team how complex some Civil Engineering designs can be."

The East Side Access project seeks to connect the Long Island Railroad directly with Grand Central Station through a tunnel that runs from Manhattan, under the East River, through a tunnel in Queens, where it connects to the main railroad lines. "One of the most difficult aspects of designing for such a project," Leonid says, "is the amount of preexisting structures that must be factored into the design."

"It can't disturb road and subway traffic," he says, though both will run above the proposed tunnel. "Also, the subway cannot move up or down in elevation. We must also factor in contaminated groundwater, which raises safety concerns."

Leonid explains, "What Schiavone is looking for from us, is how to temporarily support the structures that sit above the tunnel, as well as stabilize the soil to create safe working condition, and prevent contaminated water from leaving the site."

In other words, the physical structure of the tunnel aside, the team had to deal with the pressing issues of soil and water. The water level presented some distinctive challenges in stabilizing the area in order to dig and implement the structure.

If the tunnel is dug out without first stabilizing the ground in some way, wet soil will rush to the bottom because the site sits below the water table. The team came upon a unique solution for this problem. "We designed a way to freeze the ground," Matthew says. "Our design calls for installing freeze pipes to prevent groundwater from seeping in." Ground freezing is a unique century-old process in which pipes, extending into the earth, circulate a cooling medium such as liquid nitrogen. The cooling medium extracts heat from the soil, chilling the water in the ground until it freezes. This allows excavations at levels below the water table. "Frozen soil acts like a concrete, so it serves as an effective ground stabilization technique as well," Matthew says.

"This is kind of an unusual project with the existing structures above us and the need to dig below the water table," Dylan says. "Schiavone said they had never dealt with anything like this before – it is pretty unique."

A broad-based Stevens education prepared students with a strong foundation for this real-world project. "It pieces together so many different things that we have learned," Dylan says. "Classes in steel and concrete design really helped with designing the underpinnings. We also used the computer models to analyze the trusses, and the geotechnical engineering class came in handy in preparing our design and dealing with the soil."

The project also challenged the team to go beyond their book learning, and even beyond their extensive cooperative education experience. "This project really exposed us to Geotechnical Engineering," Matthew says. "We had all taken a geotechnical class, but this is pretty advanced work." The team members immersed themselves in advanced research, in areas such as ground freezing, grouting, and ground stabilization. "We spent a good part of the first few months just doing a massive amount of research," Matthew says. In the end, they walk away with a better understanding of geotechnical engineering, and how to innovate when presented with a very complex problem.

About Civil, Environmental, and Ocean Engineering at Stevens
The Civil, Environmental and Ocean Engineering Department strives to be the premier department in the New Jersey-New York region, and among the top universities nationwide recognized for producing well-prepared graduates, developing visible research programs, and advancing knowledge through public outreach and professional service. CEOE administers internally-known laboratories, programs, and research centers, including historic Davidson Laboratory. The department offers vibrant programs of undergraduate and graduate education and is a resource to assist in the conduct of engineering practice. Visit us at www.stevens.edu/ses/ceoe/

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