Integration of Mechanical Properties and Stability Index for the Stability Analysis of Tunnel Surrounding Rocks in a Deep Coal Mining Environment

Hasan Md Jahid; Jaja Davie

doi:10.54097/6q9hyp35

Authors

Hasan Md Jahid
Jaja Davie

DOI:

https://doi.org/10.54097/6q9hyp35

Keywords:

Rock Mechanics, Tunnel Stability, Uniaxial Compressive Strength, Stability Index, Deep Coal Mining, In-Situ Stress

Abstract

This study investigates the mechanical properties and stability classification of surrounding rock masses in deep coal mine roadways using the Guojiawan Coal Mine in Shanxi Province, China, as a case study. This study synthesized multiple parameters from laboratory testing, in situ stress measurements, and the Stability Index (SI) method to quantify stability by lithology type in a heterogeneous deep mining system. The study developed a procedure that involved collecting rock samples from the 51206 and 51207 return ventilation roadways that represented silty mudstone, fine sandstone, coarse sandstone, and coal, and utilizing the GB/T 23561.1-2009 specifications, the samples were tested using uniaxial compressive, Brazilian splitting, and triaxial compressive testing. Statistical analysis (n ≥ 3 for each test type) of the rock samples showed that coarse sandstone had the highest uniaxial compressive strength (UCS) (52.86 ± 1.85 MPa) and elastic modulus (13.11 ± 0.75 GPa), and coal had the lowest (UCS: 20.43 ± 2.15 MPa; E: 2.36 ± 0.22 GPa). In situ stress conditions were low to moderate (σH = 9.99 MPa at 270 m); however, localized stress concentrations were present next to lithologies. The SI classified coarse sandstone as stable (e = 0.30-0.44), silty mudstone as stable to moderately stable (e = 0.47-0.73), and coal seams as moderately stable (e = 0.31-0.46). The Guojiawan Coal Mine case study illustrates how using laboratory-derived parameters together with site-specific stress conditions can provide results to optimize roadway support design in deep and geologically heterogeneous mining environments, offering a transferable framework for similar underground excavations.

References

[1]H. Kang, F. Gao, G. Xu, and H. Ren, “Mechanical behaviors of coal measures and ground control technologies for China’s deep coal mines – A review,” J. Rock Mech. Geotech. Eng., vol. 15, no. 1, pp. 37–65, Jan. 2023, doi: 10.1016/j.jrmge.2022.11.004.

[2]S. Luo et al., “Stability Index of Surrounding Rock during Deep Rock Excavation Considering Energy Release Speed,” Appl. Sci., vol. 13, no. 5, p. 3000, Feb. 2023, doi: 10.3390/app13053000.

[3]K. Hou, M. Zhu, Y. Hao, Y. Yin, and L. An, “Stability analysis and evaluation of surrounding rock of ultra-deep shaft under complicated geological conditions,” Front. Earth Sci., vol. 11, p. 1216667, July 2023, doi: 10.3389/feart.2023.1216667.

[4]J. A. Hudson and J. P. Harrison, Engineering rock mechanics: an introduction to the principles, Repr. Oxford [u.a.]: Pergamon, 2007.

[5]B. H. G. Brady and E. T. Brown, Rock mechanics: for underground mining, 3rd ed. Dordrecht ; Boston: Kluwer Academic Publishers, 2004.

[6]J. Chang, K. He, Z. Yin, W. Li, S. Li, and D. Pang, “Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine,” Adv. Civ. Eng., vol. 2020, no. 1, p. 8855335, Jan. 2020, doi: 10.1155/2020/8855335.

[7]Z. Zhu, Z. Yao, J. Nemcik, and J. Han, “Investigation of Overburden Movement and Ground Stress Behaviour in Multiseam Mining,” Lithosphere, vol. 2022, no. Special 11, p. 3312379, May 2022, doi: 10.2113/2022/3312379.

[8]M. Huang, S. Jiang, Y. Zhang, Y. Jiang, X. Zhang, and C. Xu, “A new stability analysis model for wet-dry sensitive rocks surrounding underground excavations based on disturbed state concept theory,” Int. J. Rock Mech. Min. Sci., vol. 174, p. 105653, Feb. 2024, doi: 10.1016/j.ijrmms.2024.105653.

[9]D. Park and R. L. Michalowski, “Roof stability in deep rock tunnels,” Int. J. Rock Mech. Min. Sci., vol. 124, p. 104139, Dec. 2019, doi: 10.1016/j.ijrmms.2019.104139.

[10]E. Hoek and E. T. Brown, “Practical estimates of rock mass strength,” Int. J. Rock Mech. Min. Sci., vol. 34, no. 8, pp. 1165–1186, Dec. 1997, doi: 10.1016/S1365-1609(97)80069-X.

[11]Z. T. Bieniawski, Engineering rock mass classifications: a complete manual for engineers and geologists in mining, civil, and petroleum engineering. New York: Wiley, 1989.

[12]H. Kumar et al., “Comparative study of coal rocks compressive behaviors and failure criteria,” Arab. J. Geosci., vol. 12, no. 23, p. 710, Dec. 2019, doi: 10.1007/s12517-019-4914-y.

[13]H. Wu, Q. Li, C. Zhu, and P. Tang, “Stability Analysis of Surrounding Rock in Mining Tunnels Based on Microseismic Monitoring and Numerical Simulation,” Sustainability, vol. 17, no. 2, p. 630, Jan. 2025, doi: 10.3390/su17020630.

[14]J. Zhao, D. Li, J. Jiang, and P. Luo, “Uniaxial Compressive Strength Prediction for Rock Material in Deep Mine Using Boosting-Based Machine Learning Methods and Optimization Algorithms,” Comput. Model. Eng. Sci., vol. 140, no. 1, pp. 275–304, 2024, doi: 10.32604/cmes.2024.046960.

[15]S. Zhao, Y. Chen, W. Xu, J. Xu, and X. Cheng, “Mechanical behaviour and fracture mechanism of coal mine roadway surrounding rock considering seepage field,” Front. Mater., vol. 12, p. 1612136, June 2025, doi: 10.3389/fmats.2025.1612136.

[16]X. Liu et al., “Energy driven mechanism of surrounding rock deformation and failure of mining roadway and classified control technology,” Sci. Rep., vol. 15, no. 1, p. 15173, Apr. 2025, doi: 10.1038/s41598-025-98452-8.

[17]P. Luo et al., “Evaluation of excavation method on point load strength of rocks with poor geological conditions in a deep metal mine,” Geomech. Geophys. Geo-Energy Geo-Resour., vol. 9, no. 1, p. 90, Dec. 2023, doi: 10.1007/s40948-023-00629-w.

[18]Y. Xiao, S. Chen, Z. Wang, L. Liu, and C. Du, “Analyzing the Stability of Rock Surrounding Deep Cross-Tunnels Using a Dynamic Velocity Field,” Sustainability, vol. 15, no. 20, p. 15139, Oct. 2023, doi: 10.3390/su152015139.

[19]Z. Wei, W. Yang, Q. Chen, D. Liang, and G. Wu, “Uniaxial compressive strength prediction based on measurement while drilling data: A laboratory study,” J. Appl. Geophys., vol. 229, p. 105499, Oct. 2024, doi: 10.1016/j.jappgeo.2024.105499.

[20]X. Tian, L. Dou, S. Hu, X. Ma, and F. Lu, “Risk assessment and mechanism of rock burst for deep soft coal roadways,” Sci. Rep., vol. 15, no. 1, p. 7054, Feb. 2025, doi: 10.1038/s41598-025-91619-3.

[21]M. Cai and P. K. Kaiser, “In-situ Rock Spalling Strength near Excavation Boundaries,” Rock Mech. Rock Eng., vol. 47, no. 2, pp. 659–675, Mar. 2014, doi: 10.1007/s00603-013-0437-0.

[22]L. Shi and X. Zhang, “An experimental investigation on the failure behaviour of surrounding rock in the stress concentration area of deeply buried tunnels,” Bull. Eng. Geol. Environ., vol. 82, no. 12, p. 435, Dec. 2023, doi: 10.1007/s10064-023-03452-5.

[23]N. Barton, “Some new Q-value correlations to assist in site characterisation and tunnel design,” Int. J. Rock Mech. Min. Sci., vol. 39, no. 2, pp. 185–216, Feb. 2002, doi: 10.1016/S1365-1609(02)00011-4.

[24]C. Fan, J. Qin, and G. Wang, “Construction Mechanical Characteristics of TBM Pilot and Enlargement Method for Ventilation Tunnel of Wuhai Pumped Storage Power Station,” Appl. Sci., vol. 14, no. 5, p. 1829, Feb. 2024, doi: 10.3390/app14051829.

[25]Z. Ni, J. Li, K. Qin, X. Wu, J. Zhu, and S. Zhou, “Experimental study on the mechanical properties and deformation failure characteristics of sandstone under graded equal amplitude cyclic loading and unloading,” Sci. Rep., vol. 15, no. 1, p. 28735, Aug. 2025, doi: 10.1038/s41598-025-05052-7.

[26]J. Wang, H. Zhang, S. Qi, H. Bian, B. Long, and X. Duan, “Study on the Strength and Failure Characteristics of Silty Mudstone Using Different Unloading Paths,” Materials, vol. 16, no. 14, p. 5155, July 2023, doi: 10.3390/ma16145155.

[27]Y. Fan et al., “Failure characteristics and conditions of rock-coal combination structure with weak layer under dynamic and static stresses,” Sci. Rep., vol. 13, no. 1, p. 12410, July 2023, doi: 10.1038/s41598-023-39427-5.