矿用小孔径预应力拉力分散型锚索锚固结构研究及应用

Anchorage structure and the application of small aperture pre-stressed tensile dispersion anchor cable for mine

采用数值模拟方法分析了目前煤矿小孔径树脂锚固锚索剪应力分布特征,指出其受力本质为拉力集中型,在外锚固起始段会产生严重的应力集中现象,容易造成锚索锚固段渐进破坏,进而导致锚索锚固失效。通过凝胶时间达6~8h、抗压强度60MPa以上缓凝型树脂锚固剂的研发,提出了矿用新型小孔径拉力分散型锚索结构及施工工艺。在现有矿用锚索支护施工工艺不变的条件下,实现了同一钻孔内不同锚固段树脂药卷的分时分段锚固。数值计算结果表明矿用拉力分散型锚索能够将锚固段剪应力分散至两处,显著降低锚固段应力集中程度。工程应用结果表明,该技术能够大幅提高锚索内锚可靠性及锚索强度利用率,有效改善锚索内锚力与破断力的匹配性能,对巷道变形控制效果显著。

The characteristics of shear stress distribution of small-aperture resin anchorage cable in coal mine are analyzed by numerical simulation method.The tension concentration type of force nature is pointed out,and severe stress concentration will occur at the start of the external anchorage.It is easy to cause anchorage failure caused by gradual failure of anchorage section of anchorage cable.Based on the research and development of resin anchorage agent with a gel time of 6~8 h and a compressive strength of 60 MPa or more,the structure and construction technology of a new type of small aperture tensile dispersion anchor cable for mining are presented.Under the condition that the construction technology of anchor cable for existing mines is unchanged,time-division anchoring of resin coil with different Anchorage sections in the same hole is realized.The numerical results show that the tension scattered anchor cable can spread the shear stress of anchorage section to two places,the stress concentration in anchorage section is significant reduction.The results show that the technique can greatly improve the reliability of anchor and the strength utilization of anchor cable,effectively improve the matching performance of anchor force and break force in anchor cable,and significantly control the deformation of roadway.