Document Type : Original Research Paper

Authors

1 Department of Mining Engineering, Faculty of Engineering, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Pakistan

2 Department of Mining Engineering, Faculty of Engineering, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta 87300, Pakistan

3 School of Materials and Mineral Resources Engineering, University Sains Malaysia, Engineering Campus, Nibong Tebal Penang, Malaysia

4 Department of Mining Engineering, Karakoram International University, Gilgit-Baltistan, Pakistan

5 Department of Geotechnics and Transportation, Faculty of Civil Engineering, Universiti Teknologi Malaysia, Johor Bahru, Johor, Malaysia

6 Department of Geological Engineering, Faculty of Engineering, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta, Pakistan

7 Department of Transportation and Geotechnical Engineering, National University of Science and Technology, Risalpur Campus, Pakistan

10.22044/jme.2022.12294.2231

Abstract

The major factors affecting tunnel stability include the ground conditions, in-situ stresses, and project-related features. In this research work, critical strain, stress reduction factor (SRF), and capacity diagrams are used for tunnel stability analysis. For this purpose, eighteen tunnel sections are modelled using the FLAC2D software. The rock mass properties for the modelling are obtained using the RocLab software. The results obtained show that tunnel deformations in most cases are within the safety limit. Meanwhile, it is observed that the rock mass quality, tunnel size, and in-situ stresses contribute to the deformation. The resulting deformations also affect SRF. SRF depends on the in-situ stresses, rock mass quality, and excavation sequence. The capacity diagrams show that the liner experience stress-induced failures due to stress concentration at the tunnel corners. This study concludes that tunnel stability analysis must include an integrated approach that considers the rock quality, in-situ stress, excavation dimensions, and deformations.

Keywords

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