煤炭地下气化结束后，两气化炉间形成类“双曲线”形煤柱，支撑覆岩，保障气化区域安全稳定。为研究类“双曲线”形煤柱承载力学特性，基于声发射监测系统和XTDIC三维全场应变测量系统，开展了不同侧向拱高(h=0，3，7，10，13，17 mm)的6组“双曲线”形煤样单轴压缩试验，分析了h对煤样峰值载荷、变形破坏及声发射特征的影响，揭示了其承载破坏机制。结果表明：①“双曲线”形煤样可分为矩形结构(主要承载体)和侧向拱结构，其承载破坏机制与其受力形式、侧向拱结构有关；随着h增大，煤样承载能力降低，与h=0煤样相比，峰值载荷分别降低了7.66%，13.56%，26.83%，35.28%，62.75%。②随着h增大，煤样整体受力形式由以受压为主向受压–受弯曲转变，中部区域产生应力集中而形成薄弱区，对应的水平位移场向中部迁移，最终汇集于中部边缘处；而垂直位移场由水平条带状向倾斜条带状转变，最终集中于煤样侧向拱结构上端。③在轴向载荷作用下，煤样侧向拱结构对其矩形结构中部区域产生等效作用力，加之煤样非均质性影响，加剧了薄弱区损伤程度，该作用随着h增大而增强，煤样承受载荷未超过其抗拉强度即产生剪切破坏，其破坏模式由拉–剪混合破坏向剪切破坏转变，均伴随着不同程度的剥落和局部弹射破坏。④煤样声发射累计计数–时间曲线演化可分为3种类型，当h为0和3 mm时，分为“上凸”式增长、相对快速增长、快速增长、“突变”式增长4个阶段，其演化特征与常规煤岩试样一致；当h为7 mm和10 mm时，分为相对快速增长、快速增长、“突变”式增长3个阶段；当h为13 mm和17 mm时，分为快速增长和“突变”式增长2个阶段；峰后阶段均呈“突变”式增长，而峰前阶段增长形式不一致是由煤样裂纹稳定扩展和中部区域持续损伤共同导致的。

After the underground coal gasification is completed, a hyperbolic shaped coal pillar is formed between the two cavities to support the overlying rock and ensure the safety and stability of the gasification area. The work aimed to study the bearing mechanical characteristics of hyperbolic shaped coal pillar. Based on the acoustic emission (AE) monitoring system and the XTDIC 3D full-field strain measure system, 6 sets of “hyperbolic” coal samples with different lateral arch heights (h=0, 3 mm, 7 mm, 10 mm, 13 mm, 17 mm) were tested for uniaxial compression. The influence of h on peak load, deformation damage, and AE characteristics of coal samples were analyzed to reveal the bearing failure mechanism. The results are as follows. ① The “hyperbolic” coal sample can be divided into rectangular structure (main load-bearing body) and lateral arch structure, and its load-bearing failure mechanism is related to the force form and lateral arch structure. As h increases, the bearing capacity of the coal sample decreases. Compared with h=0 mm coal samples, the peak load was reduced by 7.66, 13.56, 26.83, 35.28, and 62.75%. ② The overall force form of coal samples changed from pressure-based to pressure-bending with increased h. Stress concentration occurs in the middle region of the coal sample, forming a weak area. The corresponding horizontal displacement field migrates towards the middle and finally at the edge of the middle. The vertical displacement field changed from a horizontal strip to an inclined strip, and ultimately concentrated at the upper end of the lateral arch structure of the coal sample. ③ Under axial load, the lateral arch structure of the coal sample exerts an equivalent force on the middle area of its rectangular structure, and is affected by the heterogeneity of the coal sample, which exacerbates the damage degree of the weak area in the middle. The effect increases with the increase of h, the coal sample undergoes shear failure when the load does not exceed its tensile strength. The failure mode of the coal samples shifted from tensile-shear mixed failure to shear failure, and all typical coal samples have experienced varying degrees of peeling and local ejection failure. ④ The evolution of the cumulative count-time curve of coal AE can be divided into three types. When h is 0 mm and 3 mm, it can be divided into four stages: “upward convex” growth, relatively rapid growth, rapid growth, and “sudden” growth, and its evolutionary characteristics are consistent with conventional rock samples. When h is 7 mm and 10 mm, it can be divided into three stages: relatively rapid growth, rapid growth, and “sudden” growth. When h is 13 mm and 17 mm, it can be divided into two stages: rapid growth and “sudden” growth. The post-peak stage shows a “sudden” growth pattern, while the inconsistent growth pattern in the pre-peak stage is caused by the stable expansion of coal sample cracks and continuous damage in the central region.