Androscoggin River Trail

Summit Geoengineering Services provided geotechnical consulting for the Androscoggin River Trail in Lisbon, Maine.

The project consists of a 2.13-mile bicycle and pedestrian walkway with retaining walls, culvert crossings, and an embankment 15 feet in height for a 150-foot wetland crossing. Geotechnical challenges included swamp deposits (peat) and marine deposits (soft clay) contributing to reduced bearing capacity, settlement, and slope stability limitations. An embankment section was designed having slopes of 1H:1V utilizing geotextile, riprap, and engineered fill. In addition to the geotechnical investigation, SGS completed designs for 503 feet of Stone Strong gravity retaining walls and a box culvert using LRFD methodology. SGS also performed design for a reinforced soil slope using a Geoweb© retaining system by Presto Geosystems for a slope 176 feet in length and 20 feet in height.