Turning the WB&A Railroad in Prince George’s County, MD into a bike trail as part of the East Coast Greenway was a long-awaited triumph for park officials, recreation enthusiasts, and commuters. The $4.2 million project posed quite a challenge, however, for planners, engineers and contractors. One phase required the construction of a tunnel under the highway embankment for Glenndale Drive Boulevard (MD Route 193). Limited working space and time constraints called for innovative measures.
- Location: Prince George’s County, MD
- Challenge/Unique Aspect: Traditional excavation methods, soldier piles and lagging with helical tiebacks, were the original plan, but overhead power lines, which could not be moved, became an issue. Due to limited vertical space, pile driving could not be performed. Therefore, an innovative system of soil nail wall system using soil screws and geosynthetic reinforced mechanically stabilized earth walls were utilized.
- Engineer/Architect: Earth Engineering & Sciences Inc and GeoStructures, Inc
- General Contractor: Fort Myer Construction Co