Borehole logs are important geospatial data for understanding subsurface geological and geotechnical conditions. Recently, many borehole logs in urban areas have been open to the public on the Internet in machine-readable file format. However, a few simple methods allow us to construct a voxel model of geological and geotechnical characteristics with high objectivity of the modeling process. Our work aims to develop a simple method that facilitates the use of open borehole logs in geological and geotechnical investigations in urban areas. In this paper, we propose a voxel modeling method of geotechnical data using the machine-readable open borehole logs. The method is designed to construct voxel models of lithofacies and standard penetration test results by stacking a series of horizontal two-dimensional grid data that are created by natural neighbor interpolation using geotechnical data stored in borehole logs at regular elevation intervals. A test calculation to evaluate the proposed method was performed using a large number of borehole logs in the Tokyo metropolitan area, Japan. Results confirmed that the proposed method not only allows us to ensure the objectivity of the modeling process but also provides a good overview of the three-dimensional distribution pattern of the subsurface geotechnical characteristics without any setting of complicated calculation parameters. In conclusion, the proposed method improves the efficiency of geological analyses, such as stratigraphic correlation using borehole logs, and facilitates the use of open borehole logs in urban areas.

钻孔测井是了解地下地质和岩土条件的重要地理空间数据。近来，城市地区的许多钻孔记录已经以互联网上的机器可读文件格式向公众开放。但是，通过一些简单的方法，我们可以以高度客观的建模过程来构造具有地质和岩土特征的体素模型。我们的工作旨在开发一种简单的方法，以方便在城市地区的地质和岩土勘查中使用裸眼井眼测井仪。在本文中，我们提出了一种使用机器可读的裸眼井眼测井数据对岩土数据进行体素建模的方法。该方法旨在通过堆叠一系列水平二维网格数据来构建岩相的体素模型和标准渗透测试结果，这些数据是通过自然邻域插值使用规则的高程间隔存储在钻孔测井中的岩土数据而创建的。在日本东京都会区，使用大量钻孔测井资料进行了测试计算，以评估所提出的方法。结果证实了所提出的方法不仅可以确保建模过程的客观性，而且可以很好地概述地下岩土特征的三维分布模式，而无需设置任何复杂的计算参数。总之，所提出的方法提高了地质分析的效率，