Pressure Propagation Characteristics of Solid Waste Backfilling Material During Compaction and Its Applications In Situ

Solid waste backfilling techniques are widely employed in the coal mining industry and the pressure propagation characteristics of solid waste backfilling materials are important considerations in evaluating a techniques overall effectiveness. This paper presents an experiment that evaluates the pressure propagation characteristics of backfilling materials of different particle sizes. The results show that backfilling materials with larger particle sizes have higher pressure propagation properties, while backfilling materials with smaller particle sizes are less capable of transferring pressure. Analysis indicates that there is an exponential relationship between influence factor (I) and vertical distance (Z/D), where Z/D is the depth below the center of the loading platen divided by the loading platen diameter. There is also a GaussAmp relationship between I and horizontal displacement (L/R), where L/R is the abscissa divided by the loading platen radius. The results indicate that more than 70 % of loading pressure is dissipated in the Z/D range of 0–2.75 and virtually all pressure is dissipated within the L/R range of 0–5. The results were applied in the Wugou coal mine to evaluate the effectiveness of backfilling compaction methods and the evaluate results show the backfilling compaction mechanism can work effectively.