The use of digital technology for rock mass discontinuity mapping: review of benchmarking exercise

This paper represents the results of a Benchmarking Exercise on Digital Rock Mass Discontinuity Survey 2020, which was initiated and organised by the Geotechnical Engineering Office (GEO) of the Civil Engineering and Development Department (CEDD) of the Hong Kong Special Administrative Region (HKSAR), China. The Benchmarking Exercise aimed to examine the commonality of different digital technologies developed for the rock mass discontinuity survey purpose, to explore the level of technology readiness and investigate directions of further technical development. With the contributions of the participants of this Benchmarking Exercise, useful observations of the performance of different algorithms and remote sensing methods are obtained. General discontinuity patterns and pole distributions matching with manual field measurements were reported by the participants, which facilitates reasonable kinematic assessments of rock slopes. Discontinuity properties, especially dip angle and dip direction, can be obtained in a safe manner, especially for inaccessible sites and under inclement weather conditions. However, there are limitations in some data capturing techniques, for example, slopes extensively covered by unwanted objects such as vegetation or artificial structures are not suitable for digital rock mass discontinuity survey. Depending on site settings and discontinuity patterns, suitable remote sensing methods should be adopted to minimize site constraints. Noteworthy items in the application of digital mapping and potential directions of future technical development in advancing the pertinent technology are recommended. Geo-referenced point cloud datasets for this Benchmarking Exercise are also made available at for promotion of the technical development of this subject and digital transformation of the practice in rock mass discontinuity mapping.