Test Study of Clamping-Type Basalt Fiber-Reinforced Polymer Anchors in Rock Reinforcement

Basalt fiber-reinforced polymer (BFRP) anchors, as advanced fiber-reinforced geosynthetics, provide an effective solution to long-term durability challenges in geotechnical anchorage systems. A novel clamping-type BFRP anchorage structure with cross-arranged dual anchors was developed, and it establishes a confined clamping zone through cross-arranged tendons, enabling external loads to be transmitted via combined shear and compression mechanisms across the BFRP–grout–rock interfaces. This integrated load-transfer behavior significantly enhances both energy dissipation capacity and pull-out resistance performance. Comparative analysis revealed that under soft rock conditions, the clamping-type configuration increased ultimate pull-out load and displacement by 30 and 20%, respectively, compared to conventional parallel anchors, while maintaining comparable load-bearing capacity with 15% greater displacement in competent rock formations. The failure modes exhibited fundamental differences: parallel anchors predominantly failed through localized debonding at the primary interface, whereas the clamping-type system demonstrated doubled energy absorption capacity in soft rocks. This enhanced performance is attributed to the stress redistribution mechanism within the cross-arranged configuration, which significantly improves anchorage toughness in weak rock masses.