摘要
针对沿空巷道侧向坚硬顶板垮落不及时导致巷道围岩应力和位移急剧增高的问题,利用深孔预裂爆破技术,控制沿空留巷条件下的巷道围岩变形。以南阳煤矿3208综放工作面为工程背景,利用弹性力学理论,构建工作面沿空巷道侧向悬臂梁结构模型,分析深孔爆破和巷旁支护体对岩梁应力分布的影响作用,揭示深孔爆破切顶前后巷道岩梁内部应力分布及破断规律,确定爆破切顶关键参数,对深孔爆破预裂顶板及巷道主动支护后沿空巷道的围岩控制效果开展评价。研究结果表明:深孔爆破预裂顶板能充分发挥切落岩体的自承载作用,阻挡高位岩层的下沉破断,有效改善沿空留巷顶板应力分布状态;切顶后岩梁最大主应力和剪应力明显降低,可转移沿空留巷顶板压力和减弱巷旁支护体的承载力;顶板易于在巷道煤壁上方发生压剪破坏,爆破预裂顶板以及巷旁支护体的存在,均使得巷道顶板破坏范围明显减小;3208综放工作面应设计爆破切顶高度16.8 m,爆破钻孔倾角60.3°为宜;结合锚杆锚索补强支护和单体支柱临时加强支护,可有效控制3208工作面沿空巷道变形。
Aiming at the problem that the stress and displacement of roadway surrounding rock increase sharply due to the untimely collapse of lateral hard roof of gob-side entry,deep hole blasting is used to control the deformation of roadway surrounding rock under the condition of gob-side entry retaining.The author used elastic mechanics theory to construct lateral cantilever beam structure model of working face gob-side entry based on No.3208 fully-mechanized caving face at Nanyang Mine.The influence of deep hole blasting and roadside support on the stress distribution of rock beam was analyzed.The stress distribution and fracture law of rock beam before and after deep hole blasting were revealed.The key parameters of blasting cutting roof were determined,and the control effect of surrounding rock of gob-side entry after deep hole blasting presplitting roof and roadway active support was evaluated.The results show that deep hole blasting pre-splitting roof can give full play to the self-bearing function of cutting rock mass,block the sinking and breaking of high rock strata,and effectively improve the stress distribution state of gob-side entry retaining roof.The maximum principal stress and shear stress of rock beam obviously decrease after roof cutting,which can transfer the roof pressure for gob-side entry retaining and weaken the bearing capacity of the road-side support.The roof is prone to compression-shear failure above the coal wall of the roadway.The existence of blasting pre-splitting roof and roadside support body makes the damage range of roadway roof significantly reduced.The height of blasting cutting roof should be designed to be 16.8 m,and the angle of blasting borehole should be 60.3°in the No.3208 fully-mechanized caving face.Combined with bolt-cable anchor reinforcement support and single prop temporary reinforcement support,the deformation of gobside entry can be effectively controlled in the No.3208 mining face.
作者
黄志增
高晓进
袁伟茗
孙晓冬
HUANG Zhizeng;GAO Xiaojin;YUAN Weiming;SUN Xiaodong(Ccteg Coal Mining Research Institute,Beijing 100014,China;Coal Mining and Designing Department,Tiandi Science and Technology Co.,Ltd.,Beijing 100013,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2022年第S02期88-96,共9页
Coal Science and Technology
关键词
沿空留巷
深孔预裂爆破
短悬臂梁
应力分布规律
稳态控制
gob-side entry retaining
deep borehole blasting
short cantilever
stress distribution law
stability control
