Hayward Baker completes complex landslide repair

VICKSBURG, Miss.—Geotechnical contractor Hayward Baker, Inc., recently completed an extensive landslide repair project for the Mississippi Department of Transportation (MDOT) along a stretch of U.S. Highway 61 (U.S. 61). The purpose of the work was to stabilize a failing slope that had caused the closure of both southbound lanes of U.S. 61 at Signal Hill on the outskirts of Vicksburg, Miss.

Hayward Baker installed more than 250 buried anchor blocks to stabilize the slope. According to the company, the project is noteworthy because of the size of the slide (about 1,300 feet) and the depth of the slide plane below the surface, which required use of sophisticated anchoring technology and drilled tiebacks as long as 265 feet.

Evidence of landslide activity had been observed at Signal Hill as early as 1977, shortly after completion of the roadway. An earthen berm was constructed initially, which reduced the rate of movement. There was also a trench drain-type system installed in an attempt to remove water that had collected under the roadbed in the fill area.

According to MDOT Project Manager Jeff Curtis, during the next 25 years, the roadbed sank as much as 4 feet on occasion, requiring extensive repairs. But in 2004, with continuing (and increasing) incremental movements detected, MDOT contracted with Burns Cooley Dennis, Inc. (BCD) to investigate, evaluate, and recommend a new stabilization system.

BCD recommended a permanent ground anchor/buried anchor block system because it is highly-suited to the site. MDOT approved this recommendation and, following a bid process, awarded a contract to Hayward Baker to undertake the project. Hayward Baker served as prime contractor for the 10-month, $6 million project.

According to Steve Buckner, special projects manager at Hayward Baker’s Atlanta office, which performed the repair work, Hayward Baker was one of several members of the design/engineer team assembled by BCD on the U.S. 61 project. Other participants were ABMB Engineers, Inc.; Advanced Engineering Resources, Inc.; and MDOT’s geotechnical branch.

Because of the Signal Hill project’s noteworthy design, BCD received the 2007 Grand Conceptor Award from the American Council of Engineering Companies—Mississippi.