Open this publication in new window or tab >>Show others...
2023 (English)In: Journal of Rock Mechanics and Geotechnical Engineering, ISSN 1674-7755, Vol. 15, no 9, p. 2209-2223Article in journal (Refereed) Published
Abstract [en]
Each rock joint is unique by nature which means that utilization of replicas in direct shear tests is required in experimental parameter studies. However, a method to acquire knowledge about the ability of the replicas to imitate the shear mechanical behavior of the rock joint and their dispersion in direct shear testing is lacking. In this study, a novel method is presented for geometric quality assurance of replicas. The aim is to facilitate generation of high-quality direct shear testing data as a prerequisite for reliable subsequent analyses of the results. In Part 1 of this study, two quality assurance parameters, sigma(mf) and V-Hp100, are derived and their usefulness for evaluation of geometric deviations, i.e. geometric reproducibility, is shown. In Part 2, the parameters are validated by showing a correlation between the parameters and the shear mechanical behavior, which qualifies the parameters for usage in the quality assurance method. Unique results from direct shear tests presenting comparisons between replicas and the rock joint show that replicas fulfilling proposed threshold values of sigma(mf) < 0.06 mm and vertical bar V-Hp100 vertical bar < 0.2 mm have a narrow dispersion and imitate the shear mechanical behavior of the rock joint in all aspects apart from having a slightly lower peak shear strength. The wear in these replicas, which have similar morphology as the rock joint, is in the same areas as in the rock joint. The wear is slightly larger in the rock joint and therefore the discrepancy in peak shear strength derives from differences in material properties, possibly from differences in toughness. It is shown by application of the suggested method that the quality assured replicas manufactured following the process employed in this study phenomenologically capture the shear strength characteristics, which makes them useful in parameter studies.
Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Three-dimensional (3D) scanning, Contact area measurements, Direct shear testing, Geometric quality assurance, Mechanical replicability, Replicas, Rock joint
National Category
Geotechnical Engineering
Identifiers
urn:nbn:se:kth:diva-338205 (URN)10.1016/j.jrmge.2022.12.012 (DOI)001070906500003 ()2-s2.0-85147350279 (Scopus ID)
Note
QC 20231016
2023-10-162023-10-162023-10-16Bibliographically approved