Application of high-precision 3D geological modeling technology in deep and large foundation pits of urban reclaimed water plants

Abstract

The application of 3D geological modeling technology in geotechnical engineering investigation is mostly limited to the "visualization" stage, making it difficult to fully utilize the advantages of 3D geological models. To address issues such as the difficulty of cross-platform sharing of drilling data and insufficient precision of 3D geological attribute models, based on the Phase II project of a reclaimed water plant in Beijing, the open environment of EngeoCAD survey software is used to develop drilling data interface. Based on drilling data and test data, the 3D geological structure model and high-precision attribute model of geological body are constructed, and the application of the model is verified by geological profile comparison and light cone dynamic penetration test. The results show that: The developed data interface could quickly implement the automatic import of geological drilling data from the Beijing engineering investigation cloud platform to 2D survey software, and then to professional 3D geological modeling software. Through profile comparison and analysis, the 3D geological profile shows a high degree of spatial extension consistency with the traditional 2D geological profile strata, with only slight inconsistencies in some lens bodies and thin interlayer termination points. Field measurement validation shows that the relative error in the fill volume calculated by the 3D geological model and the traditional method is 3.85% and 9.84%, respectively, demonstrating a clear advantage in the calculation accuracy of the 3D geological model. Through actual excavation layer verification, the spatial distribution domain of poor strata identified by the attribute model matches the actual strata with high accuracy. The developed data interface has bridged the gap for cross-platform sharing of drilling data in the ‘Cloud Era'. The attribute model integrates physical and mechanical parameters of geotechnical bodies into geological modeling, effectively supporting the engineering geological evaluation of site zoning and segmentation.

Keywords

3D geological modeling / attribute modeling / laboratory testing / in-situ testing