Quantitative determination of the effect of moisture and freeze / thaw cycles on coal gaugue decay rate in severe cold mining areas

This paper focuses on the weathering decay characteristics of coal gangue in severe cold mine areas. These coal gangue are subjected to the treatments of content moisture,freeze / thaw cycles and content moisture+freeze / thaw cycles under laboratory conditions,respectively. The results show that the weathering decay rate under content moisture+freeze / thaw cycles treatment is higher than that under content moisture or freeze / thaw cycles. The hierarchical clustering method is applied to analyze the decay characteristics of the coal gaugue. The sample is almost individually clas- sified into two clusters. The result also show a significant difference in content moisture+freeze / thaw cycle groups. The existence of frost crystallization wedging brings the disintegration of coal gaugue decay rates. The results also show that the effect of moisture variation,but not freeze / thaw cycle,on rock decay is a crucial factor in coal gaugue decay. Freeze / thaw cycle,in particular,affects the coal gangue,because it causes more spalling and fracturing by frost crystal- lization. The analysis suggests that the moisture content and phase plays a key role in coal gaugue decay processes.