Developing the 3D geological model in a sedimentary rock slope considering the fracture intensity distribution using borehole and LiDAR information

This study presents a 3D geological-information-based discrete fracture network (DFN) modeling approach that integrates in-situ borehole data and LiDAR measurements using statistical and probabilistic methods for a sedimentary dip slope in Taipei, Taiwan. We analyzed the information from 18 boreholes of the study site, including borehole logs and rock core samples, along with LiDAR-derived rock layer boundaries, to obtain the bedding plane and fracture information. Fisher distribution was employed to describe the orientations of the identified fractures or weak planes, while the probability density function of the fracture intensity (P10) was established to consider the fracture distribution throughout the study site. By integrating the layer boundaries, fracture orientation distributions, and the fracture density functions, we developed a heterogeneous fracture distribution model for the rock layers of the dip slope. This approach has significant potential for further 2D and 3D mechanical and hydrological applications, such as evaluating the impact of geological model uncertainty on the geotechnical reliability or conducting risk assessments for large-scale dip slopes.