Numerical Analysis of a Tunnel Subjected to Blast Loads in a Transversely Isotropic Rock Mass
Publication: International Journal of Geomechanics
Volume 24, Issue 10
Abstract
The present study investigates the stability of a tunnel subjected to blast loads. The tunnel is placed in a transversely isotropic rock mass. Numerical simulations are performed using the discrete-element method. The rock material between the bedding planes/joints is discretized as Voronoi polygons. The research focuses on the significance of discretizing the rock material between the bedding planes as Voronoi polygons for studying a tunnel’s stability under blast loads. To this end, the influence of Voronoi polygon size, joint spacing, anisotropy angle, cover depth, and earth pressure coefficient on the tunnel response are examined. The tunnel response is measured in terms of normalized crown displacement. The study provides many novel insights that can be used to improve the design of rock tunnels. It is found that it is vital to discretize rock grains as Voronoi blocks for studying the tunnel response. When Voronoi blocks are considered, the tunnel stability increases for anisotropy angles 30° and 60° but decreases for angles 0° and 90° when no Voronoi blocks are used. The tunnel becomes more vulnerable to damage as the Voronoi block size increases. It is noted that the joint spacing and Voronoi block size are interlinked, and their influence must be considered together for assessing the tunnel stability. When joint spacing is kept twice or more than the Voronoi size, the crown displacement is higher than when joint spacing is equal to or closer to the Voronoi size. It is observed that the crown displacement is maximum when the earth pressure coefficient equals 2. Therefore, the influence of change in the earth pressure coefficient is considered the most severe of all the parameters studied.
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Data Availability Statement
Some or all data, models, or codes that support the findings of this study are available from the corresponding author upon reasonable request, specifically, the numerical models created to study the tunnel stability.
Acknowledgments
The authors are grateful to Prof. Gaurav Tiwari, IIT Kanpur, for allowing us to use UDEC software. The authors are also thankful to the reviewers for the comments that helped in improving the manuscript’s quality.
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Information & Authors
Information
Published In
International Journal of Geomechanics
Volume 24 • Issue 10 • October 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: Jun 1, 2023
Accepted: Apr 4, 2024
Published online: Jul 22, 2024
Published in print: Oct 1, 2024
Discussion open until: Dec 22, 2024
ASCE Technical Topics:
- Blasting effects
- Continuum mechanics
- Design (by type)
- Dynamics (solid mechanics)
- Engineering fundamentals
- Engineering mechanics
- Geology
- Geomechanics
- Geotechnical engineering
- Joints
- Load factors
- Methodology (by type)
- Rock masses
- Rock mechanics
- Rocks
- Solid mechanics
- Spacing
- Structural design
- Structural dynamics
- Structural engineering
- Structural members
- Structural systems
- Tunnels
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