## 4 Conclusions  
This study investigated the influence of joints on rock cutting with a conical pick by conducting a series of unrelieved cutting tests. The cutting tests were conducted on jointed rock specimens with different joint spacings (\(J_{s}\)), and each test was performed at various cutting depths. The distance between the cutting path and the joint plane (\(d\)) was set from \(0.1J_{s}\) to \(0.5J_{s}\). After each test, the cutting surface was scanned using a 3D scanner to obtain the groove profiles, which were then used to analyze the rock fragmentation zone and the characteristics of crack propagation. \(FC_{m}\) initially decreased with increasing distance from the joint plane but increased again as the cutting path approached the midpoint between adjacent joints, ultimately reaching the level observed in intact rock. Regardless of cutting depth, \(FC_{m}\) reached its minimum value when \(d\) was approximately between \(0.2J_{s}\) and \(0.3J_{s}\), indicating that the influence of joints on cutting force was most pronounced within this range. The rock fragmentation zone extended beyond the joint plane when \(d\) was \(0.1J_{s}\), indicating that the influence of the joint was negligible at small \(d\). In contrast, the fragmentation zone becomes confined within the joint plane from around \(0.2J_{s}\) to \(0.3J_{s}\), further supporting that the joint effects are most significant within this range. Three types of crack propagation patterns were observed near the joint plane: (1) cracks that terminate at the joint along the shortest path, (2) cracks that pass through the joint and reach the opposite free surface, and (3) cracks that end at a free surface located just inside the joint plane. These observations suggest that the reduction in \(FC_{m}\) can be attributed to shorter crack propagation paths due to the presence of the joint. The findings of this study provide improved insight into the influence of joints in rock cutting using a conical pick. However, it should be noted that this study represents a foundational investigation conducted under simplified and controlled conditions. Specifically, the tests were limited to a single rock type (Finite limestone) and considered only artificially generated planar joints with uniform spacing, orientation, and cohesion. These assumptions may limit the generalizability of the results to more complex geological settings. To enhance the applicability of the findings, future research should incorporate a broader range of joint parameters (e.g., orientation, roughness, infill material, and mechanical strength), consider multiple rock types, and explore both experimental and numerical approaches under more realistic boundary conditions. **Author Contributions:** Conceptualization, H.-E.K. ; methodology, H.-E.K. ; investigation, H.-E.K. ; data curation, H.-E.K. and J.-S.Y. ; writing--original draft preparation, H.-E.K. ; writing--review and editing, M.-S.K., W.-K.Y. and C.-Y.K. All authors have read and agreed to the published version of the manuscript. **Funding:** This work was supported by a Korea Agency for Infrastructure Technology Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure, and Transport (Grant RS-2024-00416524, Development of technology to enhance safety and efficiency of ultra-long K-underground expressway infrastructure). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author. **Conflicts of Interest:** The authors declare no conflicts of interest. * _[PERSON] et al. (1999)_ [PERSON]; [PERSON] Roadheader excavation performance-geological and geotechnical influences. In Proceedings of the 9 th ISRM Congress, Paris, France, 25-28 August 1999. * [PERSON] (1989) [PERSON] A cutting comparison. _Tunn. Thun._**1989**, _21_, 27-30. * _[PERSON] et al.