Five Years After Landslide on U.S. 231, ALDOT Officials Proud of Its Timely Repair Efforts
In 2020, a landslide on U.S. 231 in Alabama forced the closure of the highway. ALDOT's efficient repair efforts included constructing twin bridges and mobilizing quickly, leading to an early reopening and minimal disruption for motorists.
Wed March 19, 2025 - Southeast Edition Alabama Department of Transportation & CEG
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Five years ago on March 12, 2020, leaders with the Alabama Department of Transportation (ALDOT) met with concerned residents from several northern counties to unveil an ambitious plan to repair U.S. Highway 231 after a landslide destroyed parts of the highway in Morgan County.
Heavy rain triggered the slide on Brindley Mountain in the early morning hours of Feb. 13, 2020, opening large cracks in the pavement as material shifted below. ALDOT shut down the bifurcated northbound and southbound roadways approximately 5 mi. south of Huntsville.
After studying the accident's causes, engineers found that the slide was approximately 50 ft. below both the northbound and southbound highway. The cracks and eventual failure of the roadway were the result of heavy rains that pounded North Alabama over that winter.
Prior to the slide, the highway carried a combined total of approximately 15,000 vehicles daily. Those motorists were diverted to a roughly 15-mi. passenger car detour via Union Hill Road; the commercial detour, comprised of only state routes, was more than twice as long.
During the next few weeks after the incident, contractors removed pavement and began preliminary excavation of the slide area.
To explore several potential solutions for fixing the road, ALDOT secured the assistance of geotechnical consultants Dan Brown and Associates. Drill crews and geotech engineers also probed the mountainside for answers.
"So much went into investigating the problem and identifying the best way to fix it — not just any repair, but a stable and timely one, but that wasn't visible," said ALDOT North Region Engineer Curtis Vincent. "Understandably, motorists who had been coping with the detour were growing anxious. They wondered not only how we would fix it, but how many years they would have to endure that commute."
Before a packed auditorium at Arab High School in Marshall County, Vincent and Transportation Director John Cooper laid out the agency's plan for repairing the damaged highway.
ALDOT proposed constructing twin bridges, one for each roadway, spanning the slide area, which would be deeply excavated to reduce the overburden on the slide. The 1,000-ft.-long bridges would be anchored by drilled shafts keyed into the mountain rock below the slip plane to hold the structures fast against continued movement of the slide.
Working Against the Clock
At the time, ALDOT and its contractors estimated the road would reopen approximately one year from the start of construction.
"A monumental task confronted us," Vincent said recently. "But I believed that if we remained determined, we could accomplish it in a much shorter timeframe than initially thought."
Gov. Kay Ivey's proclamation of a state of emergency due to February 2020's flood damage helped accelerate the project toward construction, ALDOT noted. Engineers also designed the bridge plans for an emergency project letting.
Meanwhile, Huntsville's Reed Contracting Inc. continued to prepare the site, excavating approximately 200,000 cu.-yds. of loose soil and rock.
ALDOT also found ways to shrink the anticipated construction timetable.
The agency shaved months off the project by ordering $4.2 million in custom-fabricated materials in advance to reduce the time for materials procurement later. With the plans ready in April 2020, ALDOT placed a six-month deadline on the project and attached up to $2.5 million in incentives for early completion.
In May 2020, ALDOT opened bids and awarded the $14.6 million contract to Brasfield & Gorrie of Birmingham; its winning bid undershot the next lowest by $5.7 million. Reed concluded the site preparation just days later, and Brasfield & Gorrie began work June 1, 2020.
Beating the Clock
Working 24-hour days and seven days a week, the prime contractor installed most of the 32 drilled shafts by late July 2020. Each drilled shaft has a diameter of 9-ft.-6-in., contains steel reinforcing pipe and has a grade beam, or ground-level strut, between each pair of shafts.
Having constructed about half the columns and caps — the above-ground substructure atop the foundations — crews also began setting 84 pre-stressed concrete girders, the long horizontal beams that would eventually support the bridge deck.
As that summer ended and restrictions brought on by the COVID-19 pandemic eased, more vehicles began returning to Alabama's roads. The congestion that made the U.S. 231 detour difficult for motorists during the first month of the closure threatened to intensify again, according to ALDOT.
But the bridge construction ultimately reached a timely conclusion. Brasfield & Gorrie built both bridges in less than four months — far ahead of the Dec. 2, 2020, deadline. The roadway finally reopened to the public in late September, providing relief for thousands of motorists.
When completed, the U.S. 231 repairs cost $27.5 million.
"Condensing planning and construction to a matter of months certainly increased the cost," Vincent said. "But if we put a number on the time and trouble it saved motorists, I think we came out ahead."
