An automated method to build 3D multi-scale geological models for engineering sedimentary layers with stratum lenses

Abstract

Automatically building three-dimensional (3D) engineering geological models of sedimentary layer is still challenging. In particular, there is a lack of practical and scientific methods for constructing models of strata containing stratum lenses and pinch-out. This study develops an engineering geological structure modeling method, called the multi-scale drill control method, for strata containing stratum lenses and stratum pinch-out using drill data. Based on the stratigraphic code classification strategy, this approach first determines n levels of stratigraphic columns in the study area and the spatial distribution and occupation relationships of each stratum inside. Thereafter, geological surfaces are interpolated, intersected, corrected, and built by following the order of the stratigraphic column from top to bottom and from coarsest to finest level. Subsequently, surfaces with 0 thickness between the top and bottom surfaces are removed, and the vertical side surfaces are constructed. Finally, geo-bodies are built on seamless surfaces to conduct model creation. As required by modelers, models of different scales are applied, or multi-scaled models are mixed for use, thus providing support for later geological analysis. The case study with complicated geological conditions indicates that the method can accurately reproduce the geo-bodies' geometry and distribution, significantly enhancing geological model building efficiency.