煤矿千米深井巷道松软煤体高压锚注-喷浆协同控制技术

Roadway soft coal control technology by means of grouting bolts with high pressure shotcreting in synergy in more than 1 000 m deep coal mines

  • 摘要: 针对煤矿千米深井巷道松软煤体大变形难题,以淮南新集矿区口孜东矿7 m大采高工作面运输巷为工程背景,分析巷道松软煤帮变形破坏特征及支护结构破坏、失效形式;采用井下试验和数值模拟相结合的方法,从锚杆锚索锚固力衰减、风化作用下煤体劣化及强流变性等方面,揭示出千米深井巷道松软煤帮大变形机理。提出千米深井巷道松软煤帮高压锚注-喷浆协同控制理念;采用数值模拟对比研究了单一锚杆锚索支护、锚注、锚注-喷浆3种方案巷道煤帮变形、裂隙及应力演化规律,阐明了巷道煤帮高预应力、高压锚注-喷浆协同控制原理。研发出高强度、高压、组合式注浆锚杆与高压注浆锚索,研究了注浆锚杆、锚索及注浆材料性能与锚注效果,形成了高预应力锚杆、锚索支护-高压劈裂注浆改性-表面喷浆协同控制技术。将上述研究成果应用于淮南新集矿区口孜东矿,提出试验巷道锚注-喷浆协同控制方案及参数,并进行了矿压监测。监测数据表明,采用提出的锚注-喷浆控制方案后,煤帮结构、完整性与强度得到显著改善,锚杆、锚索锚固力大幅提升,充分发挥了高强度锚杆、锚索主动支护作用。巷道两帮收缩量降低86%,锚杆、锚索破断率大幅减少,有效控制了千米深井巷道松软煤帮大变形,为此类深部巷道大变形控制提供了有效途径。

     

    Abstract: Coal mine roadways in more than 1 000 m deep with soft coal suffer severe squeezing and large deformation.Based on the geotechnical and engineering conditions of a maingate of a longwall panel with 7 m high mining height in the Kouzidong coal mine of Huainan Xinji mining area,a case study was performed to investigate the deformation and failure characteristics of the roadway and the failure form of the ground support.Field tests and numerical simulations were carried out to reveal the large deformation mechanism of the maingate in more than 1000 m deep with soft coal,from the aspects of attenuation of anchoring force of bolts and cables,coal deterioration under weathering,strong rheology,etc.The concept of soft coal side control with high pressure grouting bolting and shotcreting in synergy was proposed for the maingate in more than 1 000 m deep.Numerical analysis was conducted to evaluate three types of support patterns including bolts and cables,grouting bolts and cables,and grouting bolting shotcreting on roadway side deformation,and the evolution of fracture and stress fields.The coal side control principle by means of grouting bolting with high pretension and pressure and shotcreting in synergy was expounded.A combined grouting bolt with high strength and pressure,and a grouting cable with high pressure sealer were developed,the mechanical performances and reinforcement effects of grouting bolts,cables and grouting materials were studied,and the soft coal control technology by means of high pretension bolts and cablesmodification with high pressure splitting grouting shotcreting on surface in synergy was formed.The technology mentioned above has been applied in the Kouzidong coal mine of Huainan Xinji mining area,the design pattern and parameters of grouting bolting shotcreting for the experimental maingate were put forward,and underground monitoring was carried out.Field monitoring data showed that this coal control technology significantly improved the structure,integrity and strength of the coal sides.The anchoring force of the rock bolts and cables increased remarkably,giving full play to the active supporting role of the high strength rock bolts and cables.The side to side convergence was reduced by 86% comparing with the initial support pattern.Premature failure of rock bolts and cables was greatly reduced.The proposed soft coal control technology provides an effective alternative for the deep roadways with large deformation.

     

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