Experimental study of micro-damage and fracturing characteristics on raw coal under cyclic pneumatic hydraulic loading
TENG Teng
GAO Feng
GAO Yanan
ZHANG Zhizhen
Abstract：Laboratory tests for the micro-damage and fragmentation characteristics under cyclic pneumatic loading and secondary fracturing process on raw coal from Shoushan mine were performed.The experiments were conducted on rock mechanics testing system TAWD-2000 that configured with rock pneumatic fracturing equipment.Based on the damage and fractal theory,the experimental results indicate that:1) Micro-damage evolution equation is derived with the definition of residual plastic volume strain,micro-damage increases significantly with the increase of cycle-index.2) Jointed coal creates high damage area and postpones the overall damage effect of pneumatic fatigue.3) Coal specimen damaged by cyclic pneumatic loading shows overall rupture,the degree of fragmentation is much larger than the brittle diameter-tension fracturing induced by direct high gas pressure.4) The broken property of micro-damage coal can be described in quality screening method,the larger fractal dimension corresponds to higher fragmentation degree and greater occupation of small cubes.
Keywords：raw coalexperimental studypneumatic fatiguemicro-damagefractal dimension
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 306-311 )