<p>In deep underground mining, the concentrated release of surrounding rock stress can trigger rockbursts, and the loading rate plays a critical role in modifying the stress state of the surrounding rock. This study investigates the failure mechanisms of rock under varying loading rates and the corresponding rockburst characteristics through experiments and numerical simulations based on crack-induced energy evolution. Results show that loading rate significantly influences the mechanical response of granite. Both high-speed imaging and simulations reveal that rock fragmentation intensifies and crack propagation accelerates with increasing loading rate, highlighting the pronounced effect of rate on rockburst behavior. Furthermore, rock failure patterns and four rockburst proneness indices—including the residual elastic strain energy index (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">${{A}}_{\text{EF}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>A</mi> <mtext>EF</mtext> </msub> </math></EquationSource> </InlineEquation>) which increases from 262.13 to 304.11 <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\text{kJ/}{\text{m}}^{3}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mtext>kJ/</mtext> <msup> <mrow> <mtext>m</mtext> </mrow> <mn>3</mn> </msup> </mrow> </math></EquationSource> </InlineEquation>—suggest that granite exhibits a strong rockburst proneness under all tested loading rates. This proneness increases consistently with higher loading rates as evidenced by both qualitative and quantitative analyses. This study evaluates rockburst proneness from both intensity and severity perspectives by introducing two quantitative indicators: the simulated kinetic energy of rock fragments (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">${{u}}_{{sk}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>u</mi> <mrow> <mi mathvariant="italic">sk</mi> </mrow> </msub> </math></EquationSource> </InlineEquation>) and the energy dissipation index for rock fracture (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">${{U}}_{{se}}^{{d}}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mi>U</mi> <mrow> <mrow> <mi mathvariant="italic">se</mi> </mrow> </mrow> <mi>d</mi> </msubsup> </math></EquationSource> </InlineEquation>). This dual-index framework enables a more comprehensive two-dimensional assessment of rockburst suddenness and destructiveness, advancing beyond conventional one-dimensional evaluation methods. The AM-GBM simulation results exhibit strong consistency with laboratory data, confirming that the combined index serves as a practical indicator for evaluating rockburst proneness in numerical simulations. These results provide a theoretical basis for improving rock mass stability and guiding the prevention and mitigation of deep rockburst hazards in engineering practice.</p>

Crack Energy Evolution Mechanism and Rockburst Characteristics of Granite Under Varying Loading Rates: An Experimental and Numerical Investigation

期刊论文
发表日期：

2026年4月29日

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Fan Liu,
Tubing Yin,
Jiexin Ma,
Jinrun Song,
Yulong Zhao,
Hao Dai,
Xibing Li

摘要

In deep underground mining, the concentrated release of surrounding rock stress can trigger rockbursts, and the loading rate plays a critical role in modifying the stress state of the surrounding rock. This study investigates the failure mechanisms of rock under varying loading rates and the corresponding rockburst characteristics through experiments and numerical simulations based on crack-induced energy evolution. Results show that loading rate significantly influences the mechanical response of granite. Both high-speed imaging and simulations reveal that rock fragmentation intensifies and crack propagation accelerates with increasing loading rate, highlighting the pronounced effect of rate on rockburst behavior. Furthermore, rock failure patterns and four rockburst proneness indices—including the residual elastic strain energy index ( ${{A}}_{\text{EF}}$ $A_{EF}$ ) which increases from 262.13 to 304.11 $\text{kJ/}{\text{m}}^{3}$ $kJ/ m^{3}$ —suggest that granite exhibits a strong rockburst proneness under all tested loading rates. This proneness increases consistently with higher loading rates as evidenced by both qualitative and quantitative analyses. This study evaluates rockburst proneness from both intensity and severity perspectives by introducing two quantitative indicators: the simulated kinetic energy of rock fragments ( ${{u}}_{{sk}}$ $u_{sk}$ ) and the energy dissipation index for rock fracture ( ${{U}}_{{se}}^{{d}}$ $U_{se}^{d}$ ). This dual-index framework enables a more comprehensive two-dimensional assessment of rockburst suddenness and destructiveness, advancing beyond conventional one-dimensional evaluation methods. The AM-GBM simulation results exhibit strong consistency with laboratory data, confirming that the combined index serves as a practical indicator for evaluating rockburst proneness in numerical simulations. These results provide a theoretical basis for improving rock mass stability and guiding the prevention and mitigation of deep rockburst hazards in engineering practice.