GeoConcepts conducted a geotechnical engineering investigation for the reconstruction and widening of the 2-lane rural road to four lanes between Evergreen Mills Road and the Dulles Greenway. Construction would include replacing the existing 2-lane Route 606 with a new 4-lane divided highway with new intersections, bridges, stormwater management (SWM) ponds, high hazard dam improvements and more.
The field investigation involved drilling 420 test borings and completing two dilatometer tests (DMTs). Recommendations were provided regarding foundations, dam improvements, headcut erodibility, global and slope stability analyses, sound barrier walls, pavements, drainage pipe installations, stormwater management by infiltration, and earthwork.
During construction, GeoConcepts provided full-time quality control staff to monitor construction and conduct quality control testing with regard to earthwork, foundations, retaining walls, cast-in-place concrete and bituminous paving.