Abstract: Laterally loaded piles, which are commonly used in sandy stratum foundations, are particularly susceptible to necking defects during cast-in-place installation due to borehole collapse risks. These construction-induced geometric imperfections substantially compromise pile safety under lateral loading conditions. To address this critical design challenge, we develop a reliability-based multi-objective optimization framework that simultaneously accounts for structural safety, construction economy, and design robustness. The proposed methodology integrates the p-y curve (where p is the soil pressure per unit length, and y is the lateral deflection of the pile) analysis with stochastic modeling, enabling efficient evaluation of pile performance considering uncertainties in soil parameters and depth and size variations of necking defects. A systematic design framework is implemented and validated through experimental case studies, successfully generating optimal designs along the Pareto front. The identified knee-point configurations serve as practical compromise solutions for engineering decisions. Parametric investigations further elucidate the influence of necking defect depth and sand friction angle variations on optimal design outcomes, offering insights into risk mitigation for pile construction.

考虑颈缩缺陷影响的侧向受荷桩可靠度优化设计方法

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