中兴矿沿空留巷无煤柱开采条件下底鼓规律研究

Study on floor heave law of gob-side entry retaining in Zhongxing Mine

针对中兴矿多条沿空留巷开展了变形监测工作,结合一次回采、二次回采过程中巷道与工作面距离的空间关系,通过分析两次回采过程中巷道底鼓变形量的变化,研究了中兴矿沿空留巷无煤柱开采条件下的底鼓规律。研究表明:沿空留巷的底鼓变形主要由以下阶段产生:开挖及开挖稳定阶段、一次采动超前阶段、一次采动后阶段、二次采动超前阶段,其中一次采动后阶段与二次采动超前阶段是巷道底鼓产生的主要时期,产生的底鼓量占巷道使用过程中底鼓量的90%以上;沿空留巷在二次采动期间产生的底鼓变形远大于一次采动时期。建议在设计沿空留巷支护结构时,不仅要考虑一次采动的影响,更应充分考虑二次采动对沿空留巷围岩的影响。

Deformation monitoring is carried out on gob-side entry retaining of Zhongxing Mine.Floor heave laws for the first and secondary mining are studied by analyzing working resistance＇s changes of hydraulic supports and deformation of roadway.The results show that： according to the floor heave of monitoring data,variation of the floor heave is divided into four stages： excavation and the stability,first mining front support influence stage,first mining post influence stage and secondary mining front support influence stage.Among them,the first mining post influence period and secondary mining front support influence period produce over 90% of the floor heave.The secondary mining effect of floor heave is far greater than the first mining period.Suggestion is that full consideration shall be given to not only the effect of the first mining,but also to the secondary mining influence on surrounding rock along the retained roadway.