摘要
沿空留巷作为回采巷道的布置方式之一,已得到较为广泛的应用,然而,针对具体的煤层赋存条件,特别是在工作面出现大、小周期来压的工况下,沿空留巷巷旁支护阻力的确定并无充足的理论依据。基于切顶技术的应用,将引发工作面大、小周期来压的基本顶定义为复合基本顶,并细分为上位基本顶和下位基本顶,回采巷道沿空留巷布置时预切下位基本顶。据此,构建基于复合基本顶条件下沿空留巷预切顶顶板稳定性力学模型,分析上位基本顶和下位基本顶的结构特征。同时,借助“内外应力场”理论,确定上位基本顶断裂、下沉过程中形成的内应力场大小。研究提出,下位基本顶稳定性是留巷围岩控制的关键。通过分析下位基本顶从工作面前方预切顶形成的悬臂梁结构到留巷采后剧烈影响区简支梁结构的演化过程,建立沿空留巷采后剧烈影响区下位基本顶稳定性判据,并推导出保障下位基本顶稳定的巷旁支护阻力计算公式,为沿空留巷巷旁支护设计提供依据。结合具体工程条件,计算得出沿空留巷巷旁阻力为17.61 MN/m,据此优化确定泵送混凝土巷旁支护参数。现场应用表明,巷道断面收缩率控制在10%以内,围岩控制效果显著。
Gob-side entry retaining,one of the layout methods of mining roadways,has been widely applied.However,under specific coal seam conditions,especially when the working face is subjected to large and small periodic weighting,the determination of roadway-side support resistance during gob-side entry retaining lacks sufficient basis.In the application of cutting-roof technology,the basic roof that causes large and small periodic weighting to the working face is called a composite basic roof,which is further divided into an upper basic roof and a lower basic roof,and the lower basic roof is pre-cut during the arrangement of gob-side entry retaining.In this study,a mechanical model of pre-cut roof stability under composite basic roof conditions was established,and the structural characteristics of upper and lower basic roofs were analyzed.In addition,the magnitude of the internal stress field during the fracture and subsidence of the upper basic roof was determined according to the theory of"internal and external stress field".It was proposed that the stability of the lower basic roof is key to controlling the surrounding rock of the retained roadway.Then,the transformation of the lower basic roof from a cantilever beam structure formed by the pre-cut roof in front of the working face to a simply supported beam structure in the severely influenced zone after mining was analyzed.Moreover,a criterion for judging the stability of the lower basic roof in the severely influenced zone of gob-side entry retaining was established,and an equation for calculating the roadway-side support resistance to ensure the stability of the lower basic roof was provided.The equation provides a basis for determining the roadway-side support resistance in the case of gob-side entry retaining.Based on specific engineering conditions,the roadway-side support resistance was calculated to be 17.61 MN/m,and the parameters for pumped concrete roadwayside support were determined accordingly.Field applications demonstrate that the shrinkage rate of the roadway is less than 10%,indicating a remarkable effect in surrounding rock control.
作者
勾攀峰
张书军
范杰
穆朝元
赵康
陈祖国
GOU Panfeng;ZHANG Shujun;FAN Jie;MU Chaoyuan;ZHAO Kang;CHEN Zuguo(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454003,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Jiaozuo,Henan 454003,China;Guizhou Yuneng Investment Co Ltd,Guiyang,Guizhou 550081,China;Xintian Coal Mine,Guizhou Yuneng Investment Co Ltd,Bijie,Guizhou 551500,China)
出处
《采矿与安全工程学报》
北大核心
2025年第4期735-746,共12页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(51374091)。
关键词
复合基本顶
沿空留巷
切顶留巷
基本顶稳定
巷旁支护阻力
composite basic roof
gob-side entry retaining
roof-cutting entry retaining
basic roof stability
roadway-side support resistance
