Saturday, May 17, 2008

SR87 landslide clean-up, mitigation, ahead of schedule

ADOT may open all 4 lands of State Route 87 (Beeline Hwy) between Mesa and Payson by early to mid-week. The road was closed for 6 days after a landslide on Good Friday. It's been restricted to one lane in each direction while the slide was cleared off, the slope cut back, and a safety wall emplaced to prevent further slumping on to the highway.

[right top: steel girders are placed into holes more than 40 feet deep, reaching below the slide plane, forming a wall along the base of the slide]

According to Wayne Harrison, geologist with DM/JM Harris, core drilling found the slide plane about 45 feet down from the surface on the hillside above the road. A 'retaining wall' structure is being built along the slide area. About 200 feet of it will be done across the main area, providing a safety zone for traffic, while the rest of the mitigation efforts continue. This will allow southbound traffic to move back into the southbound lanes, rather than sharing the northbound side.

[bottom left: Wayne Harrison describes map of slide extent to Thomas Soteros-McNamara of the Governor's Office of Strategic Planning and Budget]

[bottom right: core hole will hold one of 3 inclinometers across the slide to monitor possible further movement]

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