Abstract Recent research has indicated the potential of optimizing the design of pile groups using system-based reliability. Binomial distribution can be used to optimize the design of redundant pile groups. The application of binomial system-reliability is challenged by the need for determining a framework for calculating a key input variable related to the maximum number of defective piles a pile group can have without collapsing under applied loads, m factor. The objective of this research is to develop two robust finite element (FE) based methods to calculate m and utilize these methods in developing a framework for optimizing the calculation of pile resistance factors in redundant pile groups using binomial reliability. The methods were developed, verified, and applied to optimize the calibration of pile resistance factors for gravity loaded pile groups in sand. The resistance factors were optimized for the number of piles in a group, spacing of piles in a group, and the method of designing the pile as opposed to the current code approach of specifying a constant resistance factor for pile design irrespective of the pile group configuration. Analysis results show that resistance factors range from 0.31 to 0.96 for a system target reliability index of 3.0.

中文翻译：

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基于二项式系统的可靠性在冗余桩群阻力系数优化标定中的应用

摘要 最近的研究表明使用基于系统的可靠性来优化桩组设计的潜力。二项分布可用于优化冗余桩组的设计。二项式系统可靠性的应用受到挑战，需要确定一个框架，用于计算与桩组在施加载荷下不会倒塌的最大缺陷桩数相关的关键输入变量，m 因子。本研究的目的是开发两种基于稳健有限元 (FE) 的方法来计算 m，并利用这些方法开发一个框架，使用二项式可靠性优化冗余桩群中桩阻力系数的计算。方法被开发、验证、并应用于砂土中重力荷载群桩桩阻力系数的优化标定。阻力系数针对一组桩的数量、一组桩的间距和设计桩的方法进行了优化，而不是当前的规范方法为桩设计指定恒定阻力系数，而不管桩组配置如何. 分析结果表明，系统目标可靠性指标为 3.0 时，阻力系数的范围为 0.31 至 0.96。