Alberta highway 858:02 embankment stabilization—geotechnical investigation, design, and construction

Abstract

An embankment failure on Highway 858:02 north of Lac La Biche, Alberta was investigated through field drilling and monitoring programs. The embankment is founded on peat and soft clay deposits. The results of field monitoring indicated that the embankment failure is characterized by translational failure mode. The failure is attributed to high groundwater table in the area and poor foundation soils. Discrete steel piles have been selected to improve the slope stability by providing horizontal restraint to the unstable embankment mass. Slope stability analyses were carried out to determine the additional resisting force required to increase the factor of safety to the desired level. The maximum shear force and bending moment that each pile has to resist were evaluated using lateral pile analyses. The pile type and number of piles were selected based on the results of the lateral pile analyses. During construction, excess pore water pressures generated by pile driving were monitored. The sequence of pile driving was controlled to minimize the risks of triggering further slope movement during construction. Show more