Reliability Analysis for Laterally Loaded Piling

Use of the design point method for reliability analysis of laterally loaded piling is described and programmed. A versatile method of modeling uncertainty in soil lateral resistance is proposed. Using this method, the soil reaction corresponding to a given deflection at a specific depth is treated as a random variable. Input soil reactions for P‐Y curves give mean values of soil resistance, with uncertainty quantified by residual reaction probability distributions. Other random variables explicitly considered include applied lateral, vertical, and moment loads at pile top, pile stress capacity, and pile top lateral deflection capacity. Vertical load and moment can be independent of or partially correlated to lateral load. Stress and deflection failure modes are considered. In the first, failure of the pile is assumed to occur when the actual maximum normal stress at any point exceeds the pile material yield point. In the second, failure is assumed to occur when the actual lateral top deflection exceeds the deflection capacity. A nonlinear analysis by the displacement method is used, including P‐delta effect and nonlinear soil springs.