Drilled Piers Used for Slope Stabilization: Final Report (Revised)

摘要

Large diameter drilled piers discretely placed so that some clear space exists between the piers can take advantage of the arching action of the soil to form a continuous barrier. The drilled piers improve the stability of the slope in two ways: by transmission of the driving stresses to more stable foundation layers, and by redistribution of the stress patterns in the slope. A three dimensional model for slopes stabilized by drilled piers has been developed for this study. This model includes provisions for mesh generation, finite element analysis and stability analysis. The finite element analysis involves nonlinear soil behavior, construction sequences and remolded surfaces around the piers. A two dimensional, limiting equilibrium analysis uses the stress field output from the finite element model to estimate the factor of safety of the slope. A number of cases are explored to give insight into the slope/pier interaction mechanisms, and to evaluate the efficiency of the piers as retaining structures. Several conditions have been considered during the course of this study: surcharge loading, excavation, cutslope and self weight loading.