我国深部煤炭开采日趋复杂，区段煤柱在采动、构造或坚硬顶底板影响下极易诱发煤柱型冲击地压，煤柱型冲击地压的防治已成为煤矿安全高效开采的难题，研究不同宽高比条件下区段煤柱的力学性能及冲击破坏特性对煤柱型冲击地压防治具有积极意义。采用不同宽高比煤样的“岩−煤−岩”组合体进行了单轴压缩实验，通过分析煤岩组合体的冲击倾向性、动态破坏特征、分形维数和声发射特征参数等，研究了宽高比对煤柱冲击破坏的影响规律。结果发现：① 煤柱的宽高比对煤岩组合体的冲击倾向性具有显著影响，宽高比不小于2:1时，其冲击能量指数K_E为1.82～2.65，冲击倾向性无明显变化；小于2:1时冲击倾向性呈先升高后降低的趋势，1:1时K_E最大，达到了15.43。② 随宽高比减小，煤岩组合体破坏特征依次表现为：拉压破坏—压剪破坏—拉剪破坏。煤柱宽高比为5:1～3:1时，煤岩组合体破坏较为缓慢；宽高比为2:1时开始出现片状煤屑弹出，冲击破坏剧烈程度较低；宽高比为1:1和0.75:1时，具有明显的冲击破坏特性；宽高比为0.5:1时，煤岩组合体整体稳定性下降，相对0.75:1煤岩组合体煤柱破坏的剧烈程度降低。③ 峰后声发射能量释放率与分形维数D变化规律相似，均随宽高比减小呈先升高后降低的趋势。宽高比不小于2:1时，煤岩组合体破坏过程中能量持续释放时间较长，煤柱破坏平缓；宽高比为1:1时，能量释放率和D值明显增大，相较宽高比不小于2:1煤岩组合体的能量释放率增大了约4倍，D值增大了0.18～0.23，煤柱冲击破坏最为剧烈；宽高比0.75:1煤岩组合体能量释放率与D值分别降低了约10%和0.01，破坏剧烈程度与1:1煤岩组合体相近；宽高比减小至0.5:1时，相关参数的降低幅度约为0.75:1煤岩组合体的6倍，破坏剧烈程度相对较小。研究表明：宽高比对煤柱的冲击破坏具有显著影响，整体上，煤柱冲击破坏剧烈程度随宽高比减小(5:1～0.5:1)呈先升高后逐渐降低的趋势；煤柱宽高比大于3:1时，煤柱冲击危险性相对较小，煤柱宽高比为1:1和0.75:1时冲击危险性较大，0.5:1次之。

The deep coal mining in China is becoming more and more complicated. Under the influence of mining, structure or hard roof and floor, the section coal pillar is easy to induce coal pillar type rock burst. The prevention and control of coal pillar type rock burst has become a difficult problem in coal mine safety and efficient mining. It is of positive significance to study the mechanical properties and impact failure characteristics of section coal pillars under different width-height ratio for the prevention and control of coal pillar type rock burst. Uniaxial compression experiments were carried out on the “rock-coal-rock”combination of coal samples with different width-height ratio. The influence of width-height ratio on the impact failure of coal pillars was studied by analyzing the impact tendency, dynamic failure characteristics, fractal dimension and acoustic emission characteristic parameters of the combination. The results show that: ① The width-height ratio of coal pillar has a significant effect on the impact tendency of the combination. When the width-height ratio is not less than 2:1, the impact energy index K_E is 1.82−2.65, and the impact tendency has no obvious change. When is less than 2:1, the impact tendency increases first and then decreases. When is 1:1, K_E is the largest, reaching 15.43. ② With the decrease of width-height ratio, the failure characteristics of the composite body are as follows: tension-compression failure-compression-shear failure-tension-shear failure. When the width-height ratio of the coal pillar is 5:1−3:1, the damage of the combination is relatively slow. When the width-height ratio is 2:1, the flake coal chips begin to pop out, and the degree of impact damage is low. When the width-height ratio is 1:1 and 0.75:1, it has obvious impact failure characteristics. When the width-height ratio is 0.5:1, the overall stability of the combination decreases, and the severity of the coal pillar failure of the 0.75:1 sample combination decreases. ③ The energy release rate of post-peak acoustic emission is similar to that of fractal dimension D, which increases first and then decreases with the decrease of width-height ratio. When the width-height ratio is not less than 2:1, the energy release time is longer during the failure process of the combination, and the coal pillar failure is gentle. When the width-height ratio is 1:1, the energy release rate and D value increase significantly. Compared with the energy release rate of the combination with a width-height ratio of not less than 2:1, the energy release rate increases by about 4 times, and the D value increases by 0.18−0.23. The impact damage of coal pillar is the most severe. The energy release rate and D value of the 0.75:1 combination were reduced by about 10% and 0.01, respectively, and the damage severity was similar to that of the 1:1 combination. When the width-height ratio is reduced to 0.5:1, the reduction of the relevant parameters is about 6 times that of the 0.75:1 combination, and the degree of damage is relatively small.The results show that the width-height ratio has a significant effect on the impact failure of coal pillars. On the whole, the intensity of impact failure of coal pillars increases first and then decreases gradually with the decrease of width-height ratio (5:1−0.5:1). When the width-height ratio of coal pillar is greater than 3:1, the rock burst risk is relatively small. When the width-height ratio of coal pillar is 1:1 and 0.75:1, the rock burst risk is larger, followed by 0.5:1.