Abstract:
Because of the large bending moments to which landslide stabilizing piles are subjected, drilled shafts used to enhance slope stability are generally reinforced with massive steel I-beams or reinforcement cages, and often incorporates several rows of tiebacks. A case history will be presented in which a minimum static Factor of Safety of 1.5 was required for the slope stabilization by the permitting agency. The application of a Factor of Safety requirement is not as straight forward as it may appear, and designs by various consultants often differ significantly for similar slopes. To avoid this type of problem stabilizing piles can be designed from both a geotechnical and structural perspective by the strength reduction method using numerical programs such as FLAC or PLAXIS. These type of numerical approach will be compared to various traditional methodologies often used by consultants.