Stabilization of a Portion of the Honby Landslide, using a Multi-Directional Approach

A proposed multi-lane cross-city corridor called for grading through an area of numerous deep-seated landslides. The grading plan design called for construction of a 1.5:1 (horizontal: vertical) to 2:1, 45 m (150 ft) high cut slope descending from a multi-media receiving facility to the proposed corridor road. The proposed design required an exception to the Uniform Building Code and the City of Santa Clarita Building Code slope requirements. Relocation of the media facility was not feasible due to line-of-site transmission requirements and realignment of the roadway was fixed due to property constraints. A cost effective solution using a combination of sequenced shear keys, geogrid-reinforced buttress fills and soldier piles was designed and constructed at an accelerated schedule. Prior to and during construction, several techniques were used to minimize potential damage to any nearby structures.