<p>The study investigated the destabilizing influence of dynamic disturbances induced by tunnel boring machine (TBM) operations on the surrounding rock. Stress paths derived from in situ stress inversion were utilized to design true-triaxial laboratory experiments, in which dynamic loading was applied to rock samples at varying radial distances from the simulated tunnel boundary. Failure patterns of hard rock were quantified under both disturbed and undisturbed conditions, with dynamic disturbances applied along the direction of the minimum principal stress (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\sigma_{3}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>σ</mi> <mn>3</mn> </msub> </math></EquationSource> </InlineEquation>). Experimental observations revealed that the crack propagation of rock accelerated subjected to dynamic disturbances and macroscopic failure modes transited from shear to tensile failure. Peak strength degradation increased as the distance away from the tunnel sidewall, demonstrating that dynamic disturbances exerted the most pronounced effect at the immediate tunnel boundary, with their influence progressively attenuating as the radial distance increased. Additionally, a strong correlation was identified between disturbance efficacy and the stress condition of rock, whereby the difference of the principal stress (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\sigma_{2} - \sigma_{3}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>σ</mi> <mn>2</mn> </msub> <mo>-</mo> <msub> <mi>σ</mi> <mn>3</mn> </msub> </mrow> </math></EquationSource> </InlineEquation>) governed the capacity to resist to dynamic loadings. Quantitative analysis indicated that dynamic disturbances reduced rock strength by 11.72%, 7.31%, 3.6%, and 1.04% at radial distances of 0.06 m, 0.69 m, 1.90 m, and 1.96 m from the tunnel sidewall, respectively. This inverse relationship between the difference of the principal stress and disturbance resistance suggests that higher stress heterogeneity accelerates rock mass damage subjected to dynamic loading.</p>

Failure Behavior of Deep Tunnels Subjected to TBM-Induced Dynamic Disturbance

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发表日期：

2026年7月10日

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Hong-Yuan Fu,
Ben-Guo He,
Si-Yuan Dou

摘要

The study investigated the destabilizing influence of dynamic disturbances induced by tunnel boring machine (TBM) operations on the surrounding rock. Stress paths derived from in situ stress inversion were utilized to design true-triaxial laboratory experiments, in which dynamic loading was applied to rock samples at varying radial distances from the simulated tunnel boundary. Failure patterns of hard rock were quantified under both disturbed and undisturbed conditions, with dynamic disturbances applied along the direction of the minimum principal stress ( $\sigma_{3}$ $σ_{3}$ ). Experimental observations revealed that the crack propagation of rock accelerated subjected to dynamic disturbances and macroscopic failure modes transited from shear to tensile failure. Peak strength degradation increased as the distance away from the tunnel sidewall, demonstrating that dynamic disturbances exerted the most pronounced effect at the immediate tunnel boundary, with their influence progressively attenuating as the radial distance increased. Additionally, a strong correlation was identified between disturbance efficacy and the stress condition of rock, whereby the difference of the principal stress ( $\sigma_{2} - \sigma_{3}$ $σ_{2} - σ_{3}$ ) governed the capacity to resist to dynamic loadings. Quantitative analysis indicated that dynamic disturbances reduced rock strength by 11.72%, 7.31%, 3.6%, and 1.04% at radial distances of 0.06 m, 0.69 m, 1.90 m, and 1.96 m from the tunnel sidewall, respectively. This inverse relationship between the difference of the principal stress and disturbance resistance suggests that higher stress heterogeneity accelerates rock mass damage subjected to dynamic loading.