Use of gINT Databases to Analyze 3D Spatial Slope Stability

The use of database applications such as gINT to manage site borehole data in geotechnical consulting practice has become common. Such databases reduce the potential cost of future site investigations and allow valuable borehole information to be managed on a broader scale between multiple offices. Such data provides a valuable source for building lithology for 3D site models. When combined with topology, geotechnical shear strength laboratory data (such as shear box or triaxial data), and geotechnical design data an improved 3D conceptual model can be constructed. Such a constructed 3D site model forms a digital twin of the proposed geotechnical design for the real site and can be subjected to analytical simulations to determine if the proposed design meets specifications. Analysis such as slope stability, seepage, and stress/deformation can be performed on the conceptual model based on 2D profile slices or on the full 3D conceptual model. The movement to performing 3D stability analysis instead of the traditional 2D profile analysis has also heightened the need for fully formed 3D conceptual models of proposed geotechnical designs at sites. 3D slope stability analysis provides the benefit of improved rigor in the calculation of the factor of safety. Calculated 3D factors of safety are higher than 2D factors of safety and allow potential for cost savings on engineering designs that may be over-conservative. These new methodologies are providing advantages in the design of large engineered structures. The additional use of spatial sweeping slope stability analysis such as the multi-plane analysis (MPA) provide maps of factors of safety which further strengthen professional design. This paper presents an integrated approach to building lithology based on a gINT database and performing 3D spatial slope stability analysis. The new approach leverages the strength of existing borehole databases and provides more rigorous analysis to aid in the design of transportation structures such as embankments, retaining walls, and slopes adjacent to roadways.