Great River Road Repairs, Keokuk, Iowa
During the summer of 2010, Keokuk, along with the entire region, experienced heavy rain and flooding which damaged numerous public and private facilities. Keokuk experienced a number of landslides within the city, one of which damaged the Great River Road from 15th Street to a point approximately 1,500 feet north of 17th Street; a distance of approximately 2,650 feet. Damage included landslides at five (5) separate locations along the road and partial failure of an existing crib/retaining wall.
In 2010 Poepping, Stone, Bach and Associates was retained to evaluate the damage, make recommendations for repairs and prepare budget estimates for said repairs.
Recommended repairs included a number or work items, such as improved storm water runoff control through additional storm sewers, adding perforated drains to control groundwater, rebuilding the damaged road and replacing the damaged portions of the crib/retaining wall with new tie-back walls and gabion walls.
In November 2011 PSBA was selected to provide engineering services for design and construction of the recommended repair work. Design engineering included preparation of the required concept statement, preliminary field surveys, preliminary project plans, check plans, final design plans, final estimate of costs and preparation of the project development certification. Construction engineering services included construction staking (surveying), construction observation/inspection and materials testing (Portland Cement Concrete and Hot-Mix Asphalt) to assure compliance with IA DOT and FHWY requirements.
During construction, continued sliding of the hillside between Great River Road and the Mississippi River were cause for concern. In order to secure the roadway from further failure, a tie back retaining wall was designed and constructed onsite between 15th Street and 17th Street, adjacent to the Rand Park area. In addition to buried piling, this retaining wall features helical tie back anchors as the main support system for the wall.