Three-dimensional geotechnical stratigraphy reconstruction method based on boundary dictionary-random forest model

Prior to geotechnical design and construction, it is quite necessary to thoroughly understand the geological conditions of the project site to ensure the safe operation of the project during subsequent stages. Reconstructing the three-dimensional geotechnical stratigraphy provides an effective approach for accurately understanding the geological conditions of the project site. Due to the complexity of geological structure spatial characteristics and the sparsity of site exploration data, it is difficult for traditional methods to reveal the boundary patterns and spatial distribution characteristics between different strata based on a small amount of site exploration data. Reconstruction of the three-dimensional stratigraphy based on limited site exploration data still faces considerable challenges. To address this problem, a series of three-dimensional distance field features is used to characterize the potential boundary characteristics between strata. This paper introduces the feature selection process of the distance field and proposes a three-dimensional stratigraphic reconstruction method based on a boundary dictionary-random forest (BD-RF) model. The effectiveness of the proposed method is validated through two engineering cases. The results indicate that the proposed method, by employing a series of three-dimensional distance field features, can effectively capture the stratigraphic distribution patterns revealed by drilling data. Compared with other methods, the proposed method has significant advantages in predicting the boundary characteristics between different strata, providing an effective analytical tool for reconstructing three-dimensional geotechnical models based on limited drilling data in practical engineering applications.

在开展岩土工程设计与施工前，全面掌握工程场地的地质条件，是保障后续工程阶段安全运行的必要前提。重构三维岩土地层，是精准认知工程场地地质条件的有效途径。受地质构造空间特征复杂、现场勘探数据稀疏的限制，传统方法难以基于少量现场勘探数据，揭示不同地层间的边界形态与空间分布特征。依托有限现场勘探数据开展三维地层重构，仍面临相当严峻的挑战。为解决该问题，本研究采用一系列三维距离场特征（three-dimensional distance field features）来表征地层间的潜在边界特征。本文阐述了距离场的特征选择流程，并提出一种基于边界字典-随机森林（BD-RF）模型的三维地层重构方法。通过两个工程案例验证了所提方法的有效性，结果表明，所提方法借助一系列三维距离场特征，可有效捕捉钻探数据所揭示的地层分布规律；相较于其他方法，该方法在预测不同地层间的边界特征方面具备显著优势，可为实际工程应用中基于有限钻探数据重构三维岩土模型提供有效的分析工具。