Predictions of settlement risk induced by tunnelling using BIM and 3D visualization tools

Ground settlements caused by tunnelling excavations are particularly important in urban areas, with greater relevance in soft soils. Estimating the settlement risk to adjacent buildings is an important consideration for tunnel planning, design and construction. In recent years the need to extend the Building Information Modelling (BIM) concept to the subsurface of modern urban areas has been increasingly emphasized, with the aim of providing better geotechnical data management and making three-dimensional (3D) data visualization more understandable. This need becomes imperative in cases of tunnelling excavations. This paper presents a newly-developed methodology to utilize 3D-BIM based models, with the associated geological information, to analyse three-dimensional models for the prediction of the tunnelling-induced settlement damage susceptibility of buildings. The engineering parameter information associated with settlement risk factors is extracted from a BIM file of a specific building project, employing the IFC standard to act as a bridge between the BIM data and MATLAB meshing and analysis tools for the evaluation of tunnel safety risks. Particular features of the methodology are that the buildings are modelled together with the ground, the subsurface geology and the representation of the tunnel, and all of them in 3D. This methodology has made use of a combination of MATLAB tools, the 3D visualization capabilities of the Sketchup design software and the conversion procedures from BIM to IFC to STL models and vice versa. As a result, the developed automated settlement susceptibility checking-platform informs tunnel construction engineers and managers by reporting, why, where and when settlement might occur, and what safety measures are needed for preventing settlement-related accidents before construction starts. An example case study of such a system is provided to illustrate the methodology, and thereby demonstrates both that adjustments to the location (alignment) of the tunnel can have a major impact on the risk of settlement-related damage.