Alberta Makes Peace
with Highway Landslides
On Judah Hill Road, tied-back tangent pile walls stabilized
the landslide mass and anchored the remaining strata
By Tyler Wilbur, Doublestar Drilling, and Craig Berninger, Champion Equipment Sales and Soilmec North America
Two-lane Highway 744, known locally as Judah Hill
Road, traverses along the southwest face of a hogback
ridge separating the Peace River and Heart River
valleys. Since it was built in 1984, active landslides
have plagued this ill-fated, 2.5-km stretch of highway that
rests above the town of Peace River, about 500 km northwest
of Edmonton.
Keeping this road open is a serious challenge.
Government of Alberta Ministry of Transportation (Alberta
Transportation) managed and remediated 15 landslides
grouped into eight areas along the ridge. These stabilization
efforts included the use of realignments, timber pile retaining
walls, mixed lime and gravel columns, anchored cast-inplace
concrete retaining walls, geotextiles, surface drainage
diversions, pumping drains, earthworks, lightweight fill and
temporary portable bridges to span failed areas.
The most recent landslide, Sunshine Slide, first visibly
impacted a 120-metre section of Judah Hill Road on May 3,
2013, when highway maintenance workers noticed transverse
diagonal cracks in the asphalt. Both lanes of the highway
continued to rapidly deteriorate, developing open horizontal
gaps up to 250 mm (9.8 inches) wide, vertical drops up to
300 mm (11.8 inches) deep and the protrusion of previously
installed large stone columns upwards through the existing
pavement structure. Alberta Transportation closed the road
due to safety concerns on May 17. By May 21, large sections
of the highway had completely collapsed due to the shifting
earth underneath the roadbed.
Even though it’s in a relatively remote area, Judah Hill
Road acts as a vital lifeline to the town of Peace River for the
thousand cars that pass along it per day. Therefore, Alberta
Transportation decided that permanently closing the
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