Stress Dynamics in Multi-Seam Coal Mining

Multi-seam coal mining is undertaken to maximise resource extraction while managing the complex interactions between successive coal seams and their rock strata. As successive coal layers are excavated, the redistribution of in situ stresses alters the stability of remaining pillars, roadways and the overburden. Key processes include the development of stress arches above goafs, the transmission of abutment pressures to adjacent seams and the compaction of collapsed strata. The thickness of intervening layers, the horizontal separation between seams and the mining sequence dictate whether stress concentrations intensify or dissipate. Repeated or upward mining increases the likelihood of roof caving, floor heave and dynamic instabilities, which pose risks to mine safety and productivity. Advances in numerical modelling, early warning systems and experimental simulations have refined our understanding of the mechanisms of roof collapse, interburden deformation and pillar bearing behaviour. This research has direct implications for design of support systems, layout of extraction sequences and mitigation of hazards such as rockburst, gas outburst and surface subsidence. Improved predictions of stress evolution are vital for safe and efficient operations in coalfields worldwide, where multi-seam deposits underpin energy security and economic development.

Research from Nature Portfolio

Recent studies have developed predictive tools for anticipating roof instabilities in multi-seam mining under repeated extraction. A granular arch mechanical model has been combined with a radial basis function neural network to identify key influencing factors such as seam separation, mining height, support load and advance rate. Field data on roof subsidence, coal wall deformation and support loads have been integrated into an early warning system that enables real-time monitoring and timely alerts for roof collapse at the working face. Practical trials have demonstrated the system’s capacity to reduce accidents by providing actionable insights for support adjustment and operational control.

Stress Dynamics in Multi-Seam Coal Mining publication trend

The graph below shows the total number of articles in stress dynamics in multi-seam coal mining across all publications each year (not limited to Nature Index journals).

Technical terms

Working face: The actual surface or location in a mine where coal is being actively extracted.

Overlying strata: Rock layers situated above a coal seam that influence stress transfer and deformation when mining occurs.

Goaf: The voided or caved region left behind after coal extraction in a longwall or plough panel.

Interburden: The rock layer or layers separating two coal seams in multi-seam mining.

Stress arch: A load-bearing structure that develops in the overlying strata or pillars, redistributing stresses around an excavation.

References

1. Study on overlying rock movement and mine pressure behavior in shallow-buried close coal multi-seam mining. Alexandria Engineering Journal (2024).
2. Failure analysis and prediction of roof instability in end face under repeated mining using early warning system. Scientific Reports (2023).
3. Study on the Instability Mechanism of Coal and Rock Mining under a Residual Coal Pillar in Gently Inclined Short-Distance Coal Seam with the Discrete Element. Sustainability (2023).
4. A Disturbed Voussoir Beam Structure Mechanical Model and Its Application in Feasibility Determination of Upward Mining. Energies (2023).