DESCRIPTION: The City of Springfield constructed a new sanitary sewer line designated as the 58th Street Relief Sanitary Sewer Line and Bypass Manhole project. The sewer line extends from the intersection of Main Street and 54th Street to the intersection of Thurston Road and 58th Street. The project included ±4,700 feet of new sewer line (±10 to 20 feet deep), approximately 17 manholes, a flow diversion structure/manhole and new service lateral connections. One of the project challenges was a bore and jack undercrossing of Highway 126 in dense gravels with shallow ground water. Other construction challenges included maintaining the stability of existing utilities while new undercrossings were being trenched nearby.
SERVICE: Foundation Engineering completed a geotechnical investigation for the project. Our work was completed in two phases. Phase I included a literature review of local subsurface information and a field reconnaissance of the alignment alternatives. The results for the Phase I work were used in the alignment selection process. Phase II included exploratory drilling and sampling along the selected alignment, installation and monitoring of piezometers, laboratory testing and development of geotechnical recommendations. We completed the investigation on time and under budget.