为研究煤岩组合体在超临界CO2作用下三轴力学特性及能量演化规律,采用超临界CO2浸泡系统,对4种不同高度比煤岩组合体试件进行浸泡和三轴压缩试验。试验结果表明:随着煤岩组合体高度比的增大,三轴抗压强度和弹性模量逐渐降低,破坏时应变变形逐渐增大。被超临界CO2浸泡后,组合体三轴抗压强度和弹性模量均有不同程度的降低;随着煤岩高度比的增大,组合体三轴抗压强度和弹性模量劣化程度逐渐增大。组合体加载破坏后,岩体部分无明显裂隙,主要为煤体发生破坏,经超临界CO2浸泡后,煤体破坏更为破碎。组合体总能量、弹性能、耗散能随煤岩高度比增大逐渐降低;超临界CO2浸泡会使组合体总能量、弹性能、耗散能降低,但耗散能占比升高。

For researching the triaxial mechanical properties and energy evolution laws of coal-rock assemblages under the action of supercritical CO , a supercritical CO immersion system was used to perform immersion and triaxial compression experiments on kinds of coal-rock assemblages with different height ratios. The experiments indicate that:(1) With the coal- rock height ratio augments,triaxial compressive strength and elastic modulus of the assemblage reduce,and the strain deformation gradually increase at the time of destruction. (2) After supercritical CO immersion,the triaxial compressive strength and elastic modulus of the combined specimens decreased to different degrees;as the rise of the coal-rock height ratio,the reduction degree of the triaxial compressive strength and elastic modulus of the combined specimens increased. (3) After loading the damage of the assemblage,there are no obvious cracks in the rock part,and the damage mainly occurs in the coal body,while the destruction of the coal body after supercritical carbon dioxide immersion is even more fragmented. (4) The total energy,elastic energy and dissipation energy of the assemblage gradually decrease with the raise of coal - rock height ratio;supercritical CO immersion reduced the total energy,elastic energy and dissipation energy of the assemblage,but the proportion of the dissipation energy augmented.