### Laser Scanner: Roughness Characterisation of Rock Mass Discontinuities  
The morphology of surfaces, quantified by [PERSON] [26] using the Joint Roughness Coefficient (_JRC_), is one of the characteristics that governs the shear strength of discontinuities. In situ, it is typically assessed by measuring one or two profiles of the discontinuities in a specified direction with a profilometer, with dimensions typically no greater than 30-40 cm, and comparing the obtained profile to typical profiles proposed by [PERSON] and ISRM. Roughness parameters of rock joints are scalependent, and their descriptors change with scale [27]. Obtaining an estimation of the roughness of a rock joint contributes to a better understanding of the failure mechanism and permeability characteristics of a rock mass [28]. _JRC_ is a parameter significantly influenced by the scale effect, which can be taken into account by adopting the precautionary expression (1) provided by [PERSON] and [PERSON] [29]. \[\tau=\sigma_{n}\tan\left[\phi_{r}+JRC\log_{10}\left(\frac{ICS}{\sigma_{n}} \right)\right] \tag{1}\]  
The authors developed the Barton-Bandis (BB) model using _JRC_ and Joint Wall Compressive Strength (_JCS_) and highlighted the importance of the scale effect. Many researchers improved the evaluation of _JRC_ by developing new methods and new parameters (i.e., the micro-average inclination angle, the roughness profile index--Rp, fractal dimension) [30; 31; 32; 33; 34; 35; 36]. However, these methods do not consider the anisotropy of the surfaces, which is also a function of the genesis of the discontinuities [37]. The measurement of joint roughness is increasingly attracting attention with the growing prevalence of high-performance computing and non-contact measurement techniques. Techniques such as photogrammetry, image processing, structured-light scanning, and laser scanning offer effective solutions for estimating Joint Roughness Coefficient (_JRC_) based on roughness measurements. The laser scanning method for assessing surface roughness relies on utilizing lasers to measure the distance to an object based on the speed of light [27; 38; 39]. High-precision information can be obtained through the use of laser scanning in the laboratory regarding the 3D roughness and anisotropy of discontinuity surfaces [40; 41; 42; 43; 44]. This has allowed for new and more refined formulations of the peak shear strength expression for rough discontinuities, overcoming the limitations associated with profilometer-based survey techniques typically performed on individual sections oriented along predetermined directions [45; 46; 47]. The laser scanner technique can also be extended to field surveys and could allow for the measurement of roughness profiles as the direction of kinematically admissible sliding varies, thus providing valuable information for the assessment of the Joint Roughness Coefficient (_JRC_) on a larger scale. According to [PERSON] et al. [48], the sampling intervals of profile lines and digital points both affect the calculated _JRC_ values. The laser scanning technique can overcome these limitations, allowing the evaluation of the anisotropy of roughness. The laser scanner survey enables a quick assessment of the rock mass quality [49; 50]. This research has focused on the use of laser scanning technology for the survey of rock mass discontinuities to determine the Barton parameters (_JRC_ and _JCS_) necessary for assessing the shear strength of the discontinuity surfaces. The utilization of a laser scanner enables the acquisition of high-precision geometrical information regarding the 3D roughness (_JRC_) and its anisotropy of rock mass discontinuity and the measurement of _JCS_ without the direct application of the Schmidt hammer on rocks. The objective pursued was to indirectly assess the in situ strength of the rock by measuring the degree of alteration through the differing emissivity of the surface when hit by a laser beam, depending on the surface's microstructure [51].