Reconstruction of a roadway over an active landslide using lightweight cellular concrete

ABSTRACT: Since the early 2000s, instability was noted along a section of Highway 762 located approximately 18 km southeast of Bragg Creek, Alberta, Canada. Distress to the pavement included significant cracking and surface undulation. Repairs consisting of pavement overlays and/or milling were conducted on approximately an annual basis in order to maintain an acceptable driving surface. A geotechnical investigation at the site revealed that the cause of the pavement distress was an underlying landslide. In late 2017, a 300 m section of the roadway was reconstructed. Key design elements used to unload the landslide included lowering the roadway grade and the novel use of lightweight cellular concrete (LCC) within the embankment. In total, approximately 5,600 m3 of LCC with a density of 475 kg/m3 were placed. Since reconstruction, no movement of the roadway has been noted and no maintenance has been required.