学术报告

题目：A re-examination of joint roughness coefficient (JRC)

Dr Louis N.Y. Wong, Associate Professor

Department of Earth Sciences, the University of Hong Kong

Abstract

Rock joints, in particular their surface morphology, significantly influence both the rock mass strength and the flow conductivity. The Joint Roughness Coefficient(JRC) scheme was proposed together with the empirical equation of shear strength by Barton in 1973, which was illustrated as ten profiles in detail and obtained from the back calculation of a series of shear tests by Barton and Choubey in 1977. However, the ten standard profiles can only provide a qualitativereference for quick and general judgments of joint roughness. To facilitate the application of JRC for surface roughness assessment to rock engineering practice, plenty quantitativecorrelations of JRC with both statistical and fractal parameters have been developed over the past decades.

The present study re-examines one of such popular roughness parameters,Z₂ (an amplitude-based parameter). By using a much objective approach of profile digitization and a careful quality checking of the digitized profiles, we believe that the present digitized profiles are more reliable for subsequent analyses. We develop a JRC- Z₂ correlation considering not only the small roughness properties, which is sensitive to the sampling interval, but also the larger scale waviness of the target surface. Results of an on-going study of assessing the capability of using ultra-close range photogrammetry for rock surface roughness measurement will also be illustrated.

Bio

Dr Louis Wong is an Associate Professor in the Department of Earth Sciences at the University of Hong Kong. He obtained his BSc degree from the same department in 1999, and PhD degree in Geotechnical and Geoenvironmental Engineering from MIT in 2008. Dr Wong was previously an Assistant Professor and Assistant Chair (Academic) in the School of Civil and Environmental Engineering at the Nanyang Technological University (NTU) in Singapore. He also worked as a consulting tunnel engineer at CDM in the USA and as an Engineering Geology Graduate in the Hong Kong Government. His teaching and research interests are in engineering geology, rock mechanics and underground engineering.

Dr. Wong has authored and co-authored more than 90 journal and conference publications. He is an editorial board member of the Journal Rock Mechanics and Rock Engineering (Springer), Journal Engineering Geology (Elsevier) and Bulletin of Engineering Geology and the Environment (Springer) and Journal of Rock Mechanics and Geotechnical Engineering(Elsevier).Dr. Wong won the Richard Wolter’s Prize 2014 from the IAEG (International Association of Engineering Geology and Environment) and the Nanyang Education Award at NTU for the academic year 2012/13.

时间： 2015年10月19日（周一）14：30

地点：力学楼二楼会议室

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