随着沿空留巷留巷跨度的逐渐增加，留巷的稳定性让人担忧，有时甚至导致留巷失败，由于对跨度对围岩稳定性的劣化作用机理不清，采取常规的加大支护强度和密度的支护方式在实际工程中没有取得很好的效果。本文采用理论分析、数值模拟和工程实践相结合的方法，研究了沿空留巷跨度对围岩稳定性的影响，取得了以下成果： 运用能量变分理论考虑塑性区范围实体煤的支撑压力，分析了直接顶的下沉变形问题，得出了直接顶的下沉量随跨度的变化规律；将顶板岩梁视为简支梁结构，计算得出了顶板可能发生四种失稳方式的临界跨度；利用弹性基础梁理论分析了老顶关键块在煤层中的断裂位置与巷道跨度的关系；建立沿空留巷叠加层板模型，运用条带法分析了顶板岩层的受力，导出了巷旁前期支护阻力和后期支护阻力与巷道跨度的关系。 以华晋沙曲煤矿24208工作面沿空留巷胶带巷为背景，采用Midas GTS分析了巷道跨度从3.5m增加到7m的过程中围岩的应力、应变动态演化规律，结果显示：随着跨度的增加，顶板围岩剪切应力集中范围不断扩大，剪切应力峰值成增加的趋势，当跨度在5.5m时，顶板剪切应力峰值产生一定程度的突变；煤帮和隔离墙的垂直应力峰值成增加的趋势，当跨度达到5.5m时，垂直应力增加幅度明显增大，煤帮垂直应力集中程度最大的点距离煤壁的距离成减小的趋势，但基本保持在2-3m的范围内；顶板水平应力集中程度大的范围区域成增大的趋势，并向实体煤帮方向扩展；巷道上方顶板的下沉量基本呈直线增长的趋势，且增大幅度较大，煤帮的下沉量基本呈直线增长的趋势，但增加幅度不大。煤帮塑性区范围随巷道跨度的增加而扩大，当巷道跨度小于5m时，煤帮等效塑性区半径基本保持不变，当跨度达到5.5m时，塑性区范围发生突变。 针对理论分析和数值模拟关于跨度对围岩的应力和变形分析，在华晋沙曲煤矿24208工作面沿空留巷胶带巷进行工业性试验，提出了相应的优化支护形式，通过现场监测验证了支护参数的合理性。

With the increase of gob-side entry retaining span, the stability of retaining roadway let the person worry, sometimes even load to the failure for gob-side entry retaining, due to the degradation mechanism is not clear about span effect on the stability of surrounding rock, it has not obtained a good effect in the practical engineering adopting the supporting method of increasing the support strength and density. This paper study the span for the influence on the stability of surrounding rock using theoretical analysis, numerical and engineering tests, the following results were obtained. The mechanical problem of the immediate roof convergence is analyzed by the variation approach of displacement by taking the abutment pressure of the solid coal in the plastic area into consideration, therefore, the changing rule of the immediate roof convergence varying with span is concluded; Four critical span is calculated when the roof loss of stability by regarding roof as a simply beam structure; The relationship between fracture position in upper roof in mine and the roadway span is analyzed by using elastic foundation theory; Overlay layer board model is built to calculated the stress of roof strata using the strip method, deduced the relationship between the early supporting force and later supporting force and span in roadside wall. The article face to gob-side entry retaining belt roadway in Huajin Shaqu 24208 mine engineering background, the stress and strain dynamic evolution law of surrounding rock are analyzed by using Midas GTS when the roadway span increased from 3.5m to7m, the results showed that, with the increase of span, vertical shear stress concentration scope expands unceasingly, surrounding rock shear peak value into a increasing trend. When the span arrived to 5.5m, the roof peak shear stress of roadway coal and wall into a increasing trend. When the span arrived to 5.5m, the vertical stress generated mutations, the stress increase rate increased significantly, the distance between vertical stress concentration degree of the largest point and coal wall grow into the trend of decrease, but always stay in the range of 2-3m. The trend of area the roof horizontal stress concentration is large present a trend of increase, and extend in the direction of coal side, The subsidence of roof and coal side present a linear trend of decrease, and the increase amplitude of roof is bigger, but the increasing amplitude of coal side is smaller, area of coal side for plastic zone of roadway and expand with the increase of the span, when the roadway span is less than 5m, coal side for the equivalent radius of plastic zone basic remain unchanged, when the span arrived to 5.5m, the plastic zone range mutations. According to the theoretical analysis and numerical simulation about the span of the surrounding rock stress and deformation analysis, industrial test is verified in gob-side entry retaining belt roadway in Huajin Shaqu 24208, the corresponding optimization support form is putted forward, the rationality of support parameters are validated by field monitoring.