An analytical method of the stabilizing force of piles for landslide control using Janbu’s generalized procedure of slices

Based on Janbu’s generalized procedure of slices (GPS) and the residual thrust method,this paper has presented a simplified calculation procedure, including upper bound method and lower bound method, for estimating the deterrent force induced by stabilizing piles in a landslide. The lower bound method assumed that sliding masses above and below each row of piles are allowed to have different values of residual thrust force or the factor of safety, and that the thrust force is a function of horizontal position. For a single row of piles, the optimization position for pile to be exerted in can be obtained by the lower bound method by trial calculation; for multiple rows of piles, the optimization configuration of the stabilizing piles can be determined by the upper bound method by limited enumeration. The combination of the two methods is greatly able to reduce computational effort for estimating the stabilizing effect without losing largely computational accuracy. It has been illustrated through an example problem that it will have better effect to using multiple rows of piles than single rows to control a large landslide. The presented systematic method can account for all available information of different stabilizing measures in an uniform frame using Janbu’s GPS.