Failure of a Pile Retaining Wall

This paper addresses the failure of a pile retaining wall constructed as a remedial measure to arrest instability of a highway embankment resulting from movement of its sideslope which was contiguous with the valley slope of a nearby creek. A drainage blanket was incorporated within the distressed section of the highway in 1983 to mitigate the pavement distress that was occurring. This remedial measure proved to be effective over a two-year period after which pavement distress re-occurred in the summer of 1990 following a period of increased rainfall. Further geotechnical investigation in 1990 resulted in the construction of a cantilever pile wall to isolate the highway from the perceived slide activity of the highway sideslope. Failure of this pile wall occurred in the summer of 1993 about 3 years after its construction, eventually requiring realignment of the highway. Failure to fully understand the site conditions from the inception of the geotechnical investigation played a major role in the short-lived performance of the remedial measures.