新型玄武岩纤维复合材料(BFRP)锚杆力学性能研究

Mechanical behavior of novel basalt fiber-reinforced polymer (BFRP) rock bolt

针对预应力锚杆的性能需求,开发了单筋型、平行索型和绞索型三种不同类型的预应力玄武岩纤维复合材料(BFRP)锚杆,研究了其拉伸、锚固和拉拔性能。结果表明,以环氧树脂作为黏结介质时,平行索的平均强度最高,达1 319 MPa。绞索由于本身捻度,受扭转作用,相较于平行索刚度和承载力有所下降,但是破坏时整体性更好,不会发生逐根破坏。采用平行-内锥式锚具时,锚杆的破坏模式为试件中间自由段纤维炸裂,锚固效率系数均大于97%。平行索的拉拔极限荷载最高,绞索的拉拔极限荷载最低,但拉拔刚度最高。

In this study, three types of BFRP cable rock bolt, namely single-tendon, parallel-tendon and twisted-tendon cable rock bolt were studied in terms of tensile, anchoring and pullout behavior. By using epoxy resin adhesive, the parallel-tendon cable had highest strength of 1 319 MPa. Owing to twisting of tendons, the tensile capacity and stiffness were reduced in twisted-tendon cable. The adoption of an anchor with inner cylinder and cone can ensure a failure mode of fiber fracture at free length. The anchoring efficiencies were larger than 97% in all groups. The parallel-tendon cable had highest pullout capacity. For pullout stiffness, however, the twisted-tendon cable was better than other cables.