运用自行研制的型煤制样设备,借助RMT–150B岩石力学试验系统对不同含水率及黏土含量下松软煤体的力学特征开展试验研究。结果表明:(1)在试验含水率(1.59%~6.50%)范围内,相同黏土含量下的松软煤体均存在一个临界含水率,在该含水率水平时,煤体的抗压强度最高、弹性模量最大;(2)黏土含量由4.00%增加到19.36%过程中,各含水率下的松软煤体抗压强度和弹性模量均呈先增后减的变化趋势,极高点黏土含量皆在11.68%左右;(3)其他条件相同时,随含水率的增大、黏土含量的增多,松软煤体脆性降低而延性增加,泊松比逐渐增大;(4)松软煤体颗粒间液桥力随含水率的变化是煤体宏观力学行为演化的主要原因,适量的黏土颗粒能够作为胶结物进一步强化煤体。研究成果对松软煤层的安全高效开采具有重要的理论意义和工程应用价值。
Using the coal preparation equipment developed by ourselves, experiments on mechanical characteristics of soft coal were studied under different moisture content and clay content with the help of RMT - 150B rock mechanics test system. The results showed that: (1) when the moisture content range from 1.59% to 6.50% in the test, critical moisture content is existed under the same clay content of the soft coal, the compressive strength of coal is the highest and the modulus of elasticity is the maximum at the level of the critical moisture. (2) The compressive strength and elastic modulus of the soft coal content were firstly increased and then decreased and the highest clay content are all about 11.68% under different moisture content when clay content increased from 4.00% to 19.36%. (3) In the same conditions, with the increase of water content and clay content, the brittleness of soft coal decreases while the ductility increases, the poisson ratio also increases. (4) The liquid bridge force of soft coal inter particles with the change of moisture content is the main reason for the evolution of the concept of mechanical behavior, the appropriate amount of clay particles can be used as cement to further strengthen the coal. The research results have important theoretical significance and engineering application value for the safe and efficient mining of soft coal seam.