This study first presents accuracy assessments of two default models proposed in two popular soil nail wall design specifications and their calibrated versions for estimation of maximum soil nail loads under operational conditions. The assessments are based on a general nail load database reported in the literature. Evaluation results showed that predictions using the default and calibrated models are unsatisfactory as the dispersions are high to extremely high. Simple calibration terms are introduced to the calibrated models for performance enhancement. The recalibrated models are shown to be accurate on average, and the prediction dispersions are significantly reduced. The model biases for the above six models are demonstrated to be lognormal random variables. Individual reliability-based designs for the nail pullout and nail-in-tension limit states using the six models are carried out. System reliability of nails against internal failures is also explored. The correlation between the two limit states is investigated, and its influences on system reliability evaluation are discussed. The practical value of model calibration is demonstrated as using the recalibrated models for nail designs leads to the most cost-effective design outcomes. This study represents a solid step toward development of reliability-based design framework for soil nail walls.

中文翻译：

---

评估土钉荷载的两种模型的评估和校准以及土钉抵抗内部破坏的系统可靠性分析

这项研究首先介绍了在两种流行的土钉墙设计规范中提出的两种默认模型及其校准版本的准确性评估，这些模型用于估算操作条件下的最大土钉载荷。评估基于文献中报告的一般指甲载荷数据库。评估结果表明，使用默认模型和校准模型进行的预测并不令人满意，因为色散范围从高到极高。将简单的校准项引入到已校准的模型中以提高性能。重新校准的模型显示平均准确，并且预测色散显着降低。以上六个模型的模型偏差被证明是对数正态随机变量。使用六个模型针对钉子拔出和钉子张力极限状态进行了基于可靠性的个性化设计。还探讨了针对内部故障的钉子系统可靠性。研究了两个极限状态之间的相关性，并讨论了其对系统可靠性评估的影响。证明了模型校准的实用价值，因为将重新校准的模型用于指甲设计可带来最经济的设计结果。这项研究代表了发展基于可靠性的土钉墙设计框架的坚实一步。事实证明，使用重新校准的模型进行指甲设计可产生最具成本效益的设计结果，从而证明了模型校准的实用价值。这项研究代表了发展基于可靠性的土钉墙设计框架的坚实一步。事实证明，使用重新校准的模型进行指甲设计可产生最具成本效益的设计结果，从而证明了模型校准的实用价值。这项研究代表了发展基于可靠性的土钉墙设计框架的坚实一步。