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US 1 Conowingo Road Wins 2020 MDQI Awards.

WRA is proud to announce that the US 1 at Conowingo Road Retaining Wall won the Maryland Quality Initiative (MDQI) MDOT SHA award Under $5M and the overall MDQI Project of the Year Under $5M award.

Prior to 1983, the Susquehanna Electric Company constructed a pedestrian walkway along US 1 for the public to access the Conowingo Dam powerhouse facility. The walkway was built on fill supported by two timber retaining walls which had since failed. After an investigation, MDOT SHA determined that the retaining walls should be replaced to prevent impacts to the US 1 roadway, and WRA developed three repair options to improve the long-term stability of the roadway slope. MDOT SHA elected to remove the existing walkway and retaining walls and construct a new retaining wall at the toe of the slope. This allowed a flatter, more stable backslope to be constructed along the US 1 roadway shoulder. WRA served as the primary design consultant and performed the geotechnical, highway, maintenance of traffic, signing and pavement marking, drainage, landscape, and erosion and sediment control design. To meet MBE goals, Mercado Consultants, Inc. performed the structural design for the proposed steel soldier pile and precast concrete lagging retaining wall. The proximity of the proposed retaining wall to the Conowingo Dam required both MDOT SHA and Exelon to work together toward a solution that would ensure the safety of the travelling public on US 1, preserve the integrity of the dam structure, and maintain access to Exelon’s facilities during construction. JJID, Inc. and their foundation subcontractor, Baltimore Pile Driving and Marine Construction, Inc. were awarded the contract. WRA geotechnical engineers monitored the wall caisson installation to meet the FERC requirements.

The Retaining Wall 12167R0 project on US 1 improved safety by both repairing the existing retaining wall failure and significantly increasing the long-term slope stability of the US 1 roadway embankment, which will prevent future emergency repairs.