Seo Wanhyuk, Yang Eomzi, Yun Tae Sup
School of Civil and Environmental Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Department of Geotechnical Engineering Research, Korea Institute of Civil Engineering and Building Technology, Goyang, 10223, Republic of Korea.
Sci Rep. 2025 Jul 2;15(1):23594. doi: 10.1038/s41598-025-08300-y.
This study introduces a novel methodology for predicting hydraulic conductivity (K) from standard penetration test (SPT) N-values, addressing the critical challenges of conventional field measurements that result in sparse K data. The research objectives were to: (1) establish empirical correlations between N and K, (2) develop a robust prediction model with quantifiable bounds, and (3) demonstrate practical applications for enhanced subsurface characterization. Analysis of 3508 boreholes across South Korea revealed a statistically significant negative correlation between N and K in sandy soils. Quantile regression enabled prediction of both point estimates and percentile ranges. Evaluation of six empirical equations for K estimation identified the Chapuis equation as optimal, which was integrated with field measurements to strengthen the regression model. For weathered rocks, a consistent K range was established. The methodology's novelty lies in combining readily available SPT data with advanced statistical techniques to generate high-resolution 3D K domains, as demonstrated through kriging. Despite relatively low R values, the methodology achieves practical accuracy with most predictions falling within one order of magnitude of measured values. This approach significantly enhances spatial and depth-wise characterization of subsurface K, offering a practical solution for groundwater flow modeling and geotechnical design with improved resolution.
本研究介绍了一种从标准贯入试验（SPT）N值预测水力传导率（K）的新方法，解决了传统现场测量导致K数据稀疏的关键挑战。研究目标是：（1）建立N与K之间的经验相关性，（2）开发具有可量化界限的稳健预测模型，以及（3）展示增强地下特征描述的实际应用。对韩国3508个钻孔的分析表明，砂土中N与K之间存在统计学上显著的负相关。分位数回归能够预测点估计值和百分位数范围。对六个估算K的经验方程进行评估后，确定Chapuis方程为最优方程，并将其与现场测量数据相结合以强化回归模型。对于风化岩石，确定了一致的K范围。该方法的新颖之处在于将易于获取的SPT数据与先进的统计技术相结合，以生成高分辨率的三维K域，如通过克里金法所展示的那样。尽管相关系数R值相对较低，但该方法在大多数预测值落在测量值的一个数量级范围内时达到了实际精度。这种方法显著增强了地下K的空间和深度特征描述，为具有更高分辨率的地下水流建模和岩土工程设计提供了一种实用解决方案。
