Yield Acceleration of a Slope Reinforced with a Row of Drilled Shafts

摘要

The slope stabilization techniques involving the use of a single row of drilled shafts have been widely adopted for repair or strengthening of the natural slopes or embankment slopes on highways. The performance of the drilled shafts stabilized slopes under earthquake excitations, however, has not been studied previously. In this paper, a method for estimating the yield acceleration of the drilled shaft/slope system under a seismic excitation is presented. The method is based on the concept of soil arching developed in the slope mass adjacent to the rigid inclusions of drilled shafts, which in turn reduces the driving force on the slope. Considering soil arching effects and earthquake-induced inertia forces, a limiting equilibrium based formulation was derived. A computer program was coded to allow for the calculation for complex slope geometry and soil profiles. The validity of the derived method is illustrated with an example. Once yield acceleration is computed, then Newmark's method can be evoked to estimate permanent displacement of the drilled shafts reinforced slope under an earthquake excitation.