大变形巷道弹性锚喷混凝土耦合支护技术研究及应用

为提高层理地质条件下大变形巷道的稳定性,延长巷道使用寿命,采用具有较大变形承载能力的喷钢纤维混凝土与弹性锚杆耦合支护技术加固围岩。首先研究层理状地质条件下高应力软岩巷道的破坏特点及规律,确立支护结构和时效耦合的关系,并通过钢纤维混凝土试样的动静荷载试验,研究混凝土强度与钢纤维掺量的关系,得到喷钢纤维混凝土合理的钢纤维掺量。此外,针对大变形巷道开挖初期变形量大、破坏速度快的特点,设计具有让压吸能作用的新型弹性锚杆,并将此弹性锚杆结合喷钢纤维混凝土技术进行工业试验,试验的位移监测结果表明:该方案位移量比原方案减小约50%,且支护10个月后未出现裂缝。

Technical Study and Application of Elastic Bolt/Sprayed Steel Fiber Concrete Coupling Support in Large Deformation Roadway

For the sake of improving stability of large deformation roadways under bedding geological conditions and prolonging the service life a coupling support technology of elastic combined sprayed steel fiber concrete and elastic rock bolt was used.Firstly,damage feature and law of high stress soft rock roadway in bedding geological conditions were studied and the relationship between structure and aging coupling was revealed.On the other hand,the relationship between steel fibber content and concrete strength was studied and the reasonable steel fiber content was obtained by dynamic and static load experiments with steel fiber content samples.Bearing it in mind that at the beginning of excavation of a large deformation roadway,the deformation was large and the roadway was more prone to fracture quickly,a new elastic bolt with energy-absorption was designed.The coupling support technology of elastic combined sprayed steel fiber concrete and elastic rock bolt was tested in the field.The displacement monitoring result shows that the stability of test roadway is greatly improved and the displacement is shorten by 50%.After 10 months there were no cracks in the test roadway.