Analysis of Landslides and Slopes Stabilized Using One Row of Piles-PDF

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This report develops and validates a design method for analyzing slopes stabilized by a single row of piles. Existing approaches are limited: pressure-based methods generally estimate ultimate resistance only, while many displacement-based methods simplify soil and pile behavior and omit pile-group effects. Three-dimensional numerical analyses can represent these effects but are computationally demanding.<br /><br />The proposed method adapts the Strain Wedge model to calculate how moving soil transfers nonuniform lateral pressure to piles. It accounts for relative soil–pile displacement, nonlinear soil behavior, pile properties and embedment, slip-surface depth, and interaction between adjacent piles both above and below the failure surface. The method identifies different response and failure modes, including soil flowing around the pile, intermediate behavior in which the pile deflects beyond the soil movement, insufficient pile embedment, and structural failure. It also calculates pile deflection, shear, bending moment, resistance, and slope safety factors. The analysis was implemented in the PSSLOPE-M software.<br /><br />Predictions were compared with measurements from two field cases and with 3D finite-element simulations; the report found generally good agreement. Results show that pile spacing and sliding-mass depth strongly affect load transfer and group action. Closer spacing can increase the total resistance provided by a row, although it may reduce the ultimate resistance carried by each pile in shallow-slide conditions. Deeper slip surfaces tend to produce more flexible pile behavior and make structural capacity more influential. Overall, the method offers a practical framework for evaluating pile–soil interaction and the stability improvement provided by stabilizing piles.

Keywords

slope stabilization

stabilizing piles

pile-soil interaction

Strain Wedge model

lateral soil pressure

pile group effects

slope safety factor

pile deflection

finite element validation

slip surface depth