To address the problem of the concrete filling body (CFB) force failing to reach test strength in remaining roadways, the weakening effects due to aspect ratio and dimensional parameters on the actual CFB strength were investigated in this study. The geometric effects of CFB (including hoop and size effects) as well as the geometric effect coefficient determination method were analysed. Through laboratory tests and PFC numerical simulations, the hoop and size effect coefficients of the CFB in the Gaohe Coal Mine were studied. Furthermore, the calculation equations of actual strength and bearing capacity of the CFB were derived. Regarding the filling body failure and coal deformation in the remaining roadway located at the No. W1319 working face, the actual bearing capacity of CFB and surrounding rock stability during secondary exploitation were theoretically studied. The investigation suggests the adoption of a grouting reinforcement scheme for surrounding rock. The field applications performed have demonstrated that the deformation control effect in the remaining-roadway surrounding rock was effectively improved during second mining and the filling body beside the roadway suffered no additional damage. Studying the geometric effect of CFB can provide some theoretical guidance and industrial significance to accurately identify the filling body strength and reduce the failure risk of surrounding rock in remaining roadways.

中文翻译：

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剩余综放巷道混凝土充填体几何效应研究

针对剩余巷道混凝土填充体（CFB）受力未能达到试验强度的问题，本研究研究了纵横比和尺寸参数对实际CFB强度的弱化影响。分析了CFB的几何效应（包括箍效应和尺寸效应）以及几何效应系数的确定方法。通过室内试验和PFC数值模拟，研究了高河煤矿CFB的环向和尺寸效应系数。进而推导了CFB实际强度和承载力的计算公式。关于W1319工作面剩余巷道充填体破坏及煤层变形，对二次开采过程中CFB的实际承载力和围岩稳定性进行了理论研究。调查建议采用围岩注浆加固方案。现场应用表明，二次开采有效提高了剩余巷道围岩的变形控制效果，巷道旁充填体未发生额外破坏。研究CFB几何效应可为准确识别充填体强度、降低剩余巷道围岩破坏风险提供一定的理论指导和工业意义。现场应用表明，二次开采有效提高了剩余巷道围岩的变形控制效果，巷道旁充填体未发生额外破坏。研究CFB几何效应可为准确识别充填体强度、降低剩余巷道围岩破坏风险提供一定的理论指导和工业意义。现场应用表明，二次开采有效提高了剩余巷道围岩的变形控制效果，巷道旁充填体未发生额外破坏。研究CFB几何效应可为准确识别充填体强度、降低剩余巷道围岩破坏风险提供一定的理论指导和工业意义。