The City of South Bend hired DLZ to provide a comprehensive range of services for the Olive/Sample Road and Bridge Reconstruction Project. These services included surveying, geotechnical, environmental, and design. The project involved replacing the existing concrete pavement along 6,000 feet of Olive Street and Sample Street alignment. Additionally, it involved replacing the bridge deck on the Olive and Sample Street bridges over the Grand Trunk Western Railroad. Thus, a roundabout replaced the existing conventional intersection at Olive Street and Sample Street. Also, Olive Street north and south of Sample Street was reduced from four to two lanes.
Using a modern multi-lane roundabout to replace a signalized intersection on top of an existing railroad, overpass demonstrates a unique application of new technology. While not the solution for traffic backups during peak travel times, the roundabout is operating as expected. It has relieved traffic congestion at the intersection.
The DLZ Team was responsible for developing a solution to eliminate an existing combined sewer along south Olive Street. Due to impracticalities with the existing drainage system, DLZ incorporated a sub-surface underground storage system into the project. This allows for overflows to the existing storm sewer system. The incorporation of a green underground infiltration system effectively extended the existing gravity drainage system while increasing the stormwater storage capacity.
DLZ performed the geotechnical engineering exploration for the new roadway alignment and a proposed 16.5-foot high MSE retaining wall in the northwest quadrant of the South Olive Street and West Sample Street Intersection. Stability and settlement analyses were performed in accordance with AASHTO LRFD Specifications.