Dynamic Behavior of Blocky Rock Masses

The dynamic behaviour of blocky rock masses arises from the interaction of discrete rock fragments under transient and sustained loads. Such masses comprise irregularly shaped blocks separated by joints, fractures and interstitial material of lower stiffness. When subjected to seismic waves, blast-induced stress waves or combined static and dynamic loading, block contacts undergo cyclic loading, rapid strength degradation and intermittent slip. These processes control energy dissipation, fragmentation and the onset of catastrophic events such as rock bursts, landslides or slope failures. Key factors include block geometry, joint stiffness, contact roughness and in situ stress conditions. Laboratory and numerical studies have elucidated how vibration frequency, amplitude and confining pressure influence frictional resistance and the progressive mobilisation of shear bands along block contacts. The outcome of these interactions has direct implications for underground excavation safety, design of rock-support systems and the prediction of natural hazards in mountainous regions.

Research from Nature Portfolio

Recent studies have investigated slip instability in block rock masses under combined dynamic and static loading. Modelling analyses reveal that oscillatory vibrations modulate normal and shear components of contact forces, leading to sudden frictional drops when vibration amplitude exceeds a threshold. The theoretical framework identifies a critical thrust and timing for slip initiation, determined by block stiffness, joint geometry and vibration frequency. These findings provide new criteria for assessing the risk of rock burst in deep mining and offer analytical expressions for the critical conditions of block slipping, enabling improved hazard assessment in high-stress underground environments.

Dynamic Behavior of Blocky Rock Masses publication trend

The graph below shows the total number of articles in dynamic behavior of blocky rock masses across all publications each year (not limited to Nature Index journals).

Technical terms

Blocky rock mass: A rock system composed of discrete fragments or blocks separated by joints and fissures.

Slip instability: Sudden relative movement along block contacts when frictional resistance drops below applied shear stress.

Stress wave: A transient elastic disturbance that propagates through rock, generated by seismic events, blasts or impacts.

Ultra-low friction: A marked reduction in inter-block friction under dynamic disturbance, often leading to sliding.

Dimensionless energy parameter: A scaled measure of input disturbance energy used to predict the onset of slip or failure in block systems.

References

1. Slip instability behavior of block rock masses on dynamic-static combined loads. Scientific Reports (2023).
2. Influence of stress wave-induced disturbance on ultra-low friction in broken blocks. International Journal of Coal Science & Technology (2022).
3. Experimental Investigation and Analysis of Triggering Mechanism for Fault‐Slip Bursts of the Tunnel Surrounding Rock with External Disturbance. Shock and Vibration (2018).