Hayward Baker Inc., a leading geotechnical contractor, recently announced the completion of an ambitious landslide repair project for the Mississippi Department of Transportation (DOT). The work was conducted along a stretch of U.S. Highway 61, one of the nation's landmark roads that extends from the Canadian border to the Gulf of Mexico.
The purpose of the work was to stabilize a failing slope that had caused the closure of both southbound lanes of U.S. Highway 61 at Signal Hill on the outskirts of Vicksburg, Miss. As the general contractor for the project, Hayward Baker installed more than 250 buried anchor blocks to stabilize the slope. The project is noteworthy because of the size of the slide--about 1,300 ft--and the depth of the slide plane below the surface, which necessitated the use of the sophisticated anchoring technology and drilled tiebacks as long as 265 ln ft.
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 also was a trench drain-type system installed in an attempt to remove water that had collected under the roadbed in the fill area.
According to Jeff Curtis of the Mississippi DOT, over the course of the next 25 years the roadbed would sink as much as 4 ft on occasion, requiring extensive repairs. But with continuing and increasing incremental movements being detected, in 2004 the Mississippi DOT contracted with Burns Cooley Dennis Inc. (BCD) to investigate, evaluate and recommend a new stabilization system.
A permanent ground anchor/buried anchor block system was recommended by BCD because it was highly suited to the site. This recommendation was approved by the Mississippi DOT, and the contract was awarded to Hayward Baker to undertake the project following a bid process.
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. Highway 61 project. Other participants included ABMB Engineers Inc., Advanced Engineering Resources Inc. and the Mississippi DOT's own geotechnical branch.
"The project was a great success," Buckner said. "The Mississippi DOT manager reported that he had never worked with a more professional organization than Hayward Baker."
Because of the Signal Hill project's noteworthy design, BCD received the 2007 Grand Conceptor Award from the American Council of Engineering Cos.-Mississippi (ACEC-MS). The award was given at the annual ACEC-MS Engineering Excellence Awards banquet held Feb. 21 in Jackson, Miss.