深井软岩巷道底板卸压钢丝绳网锚注支护技术研究

Study on the bolt-grounding support technology with wire-rope mesh of floor stress-relief slot for soft-rock roadway in deep shaft

针对平顶山天安煤业股份有限公司一矿深井软岩回风上山巷道工程地质条件和围岩变形特征,采用数值计算方法,研究了底板卸压槽卸压前后巷道围岩应力场、塑性区的变化规律,分析了底板卸压槽卸压机理,提出了钢丝绳网锚注支护技术,并进行了工业性试验。研究结果表明:(1)巷道底板开掘卸压槽卸压后,底板围岩垂直应力和水平应力的高应力区及其峰值应力均向底板深部转移。卸压后底板同一深度的围岩应力均小于卸压前的围岩应力;卸压后巷道顶底板和两帮围岩的塑性区范围均增大,底板卸压效果明显。(2)深井巷道围岩的破碎区和部分塑性区是支护的重点。回风上山巷道采取开挖底板卸压槽、钢丝绳网锚杆支护和围岩注浆加固等支护措施后,在围岩中形成了锚注体支护圈,提高了围岩的强度和自身承载能力。巷道围岩经历加速变形阶段、减速变形阶段和稳定变形阶段后,一直处于稳定变形状态。卸压槽+钢丝绳网锚注支护在回风上山巷道的支护试验取得成功,可为深井软岩巷道支护提供参考依据。

Aiming at the engineering geological conditions and deformation characteristics of the surrounding rocks of soft-rock return-air rise roadway in deep shaft of No.1 Mine of Pingdingshan Tian’an Coal Co.,Ltd.,China,the change laws of stress field and plastic zone of the surrounding rocks of roadway(TSRR)before and after depressurization with floor stress-relief slot were studied with numerical calculation.Depressurization principle of floor stress-relief slot was analyzed and the bolt-grounding support technology with wire-rope mesh was put forward.The results showed that:(1)after the floor stress-relief slot was excavated,the high stress areas and the peak stress in the vertical and horizontal directions in the floor TSRR both were transferred to the floor deep surrounding rocks.The stress of surrounding rocks at the same floor depth of roadway after depressurization was less than that before depressurization.After depressurization,the plastic zones in the roof,floor and two sides of TSRR all increased,the effect of the floor stress-relief was obviously.(2)The broken zone and partial plastic zone of TSRR in deep shaft were the key points of roadway supporting.After the construction of floor stress-relief slot and bolt support with wire-rope mesh,the surrounding rocks grouting reinforcement fully were completed,the support-ring with bolt-grouting rock mass was formed in TSRR.Therefore,the strength and self-supporting capacity of TSRR were improved.After the deformation of TSRR undergoes accelerated deformation stage,decelerated deformation stage,and stable deformation stage,TSRR had been in stable deformation state.Thus,the supporting tests of bolt-grounding support with wire-rope mesh and floor stress-relief slot had been successful in return-air rise roadway.