Tren Urbano-Rio Piedras Rapid Transit System

As America’s first design-build underground transit project, the Tren Urbano-Rio Piedras rapid transit system involved construction of 10.4 miles of track, a one mile long tunnel and two underground stations for the Puerto Rico Highways and Transportation Authority.

Three different soft-ground tunneling methods were implemented to address ground conditions. The work involved the delivery of retained-cut/retained-fill at both ends of the project, as well as cut-and-cover double and single-cell box structures. A total of 1,300 ft. of the tunnel has cast-in-place lining. The project has 1,400-ft. twin transit tunnels excavated with an Earth Pressure Balance Machine, 1,260 feet excavated using the New Austrian Tunneling Method, one cut-and-cover station and a 75-ft.-wide by 55-ft.-high by 410-ft.-long underground mined station constructed using stacked drift techniques.

The work was performed within the busy urban area of San Juan with only minimal disruption to normal surface activities. All facilities were constructed with full waterproofing and drainage systems.

Mass. Electric Construction Co. (MEC) installed the control center including traction power train control and communications systems for the 10.4-mile extension. MEC currently has a contract to maintain the system.