铁道建筑

针对有砟轨道传统木枕长期服役中易腐朽、开裂和磨损，而传统防腐加固环保与成本难兼顾的问题，本文提出玄武岩纤维布（BFRP）包覆加固技术。通过三点抗弯试验，结合数字图像相关技术（DIC），研究局部锚固、单层全包覆和双层全包覆对新木枕力学性能及破坏机理的影响，并将该技术用于退役防腐油浸旧木枕修复。结果表明：BFRP包覆可显著提高木枕极限承载力，相较于未加固木枕可提升12.7%～15.4%，其中双层全包覆效果最优，单层全包覆性价比最高；BFRP可以有效分担拉应力，延缓裂缝扩展，使破坏由脆性断裂转向延性破坏。旧木枕单层全包覆后平均极限承载力达152.7 kN，平均弯曲强度24.41 MPa，力学性能明显恢复。BFRP加固技术增强效果显著，经济性好，适用于铁路木枕维护和再生利用。

To address the susceptibility of conventional timber sleepers in ballasted track to decay， cracking， and wear during long-term service， and the difficulty of balancing environmental performance and cost in conventional preservation and strengthening methods， a basalt fiber-reinforced polymer (BFRP) wrapping technique is proposed. Three-point bending tests combined with digital image correlation (DIC) were conducted to investigate the effects of local anchorage， single-layer full wrapping， and double-layer full wrapping on the mechanical properties and failure mechanisms of new timber sleepers; the technique was also applied to the repair of retired preservative-oil-impregnated timber sleepers. Results showed that BFRP wrapping increased the ultimate load-bearing capacity by 12.7%-15.4% relative to unreinforced sleepers. Double-layer full wrapping produced the greatest increase， whereas single-layer full wrapping provided the best cost-effectiveness. The BFRP layer shared tensile stress and delayed crack propagation， shifting the failure mode from brittle fracture toward more ductile failure. After single-layer full wrapping， the retired sleepers achieved an average ultimate load-bearing capacity of 152.7 kN and an average flexural strength of 24.41 MPa， indicating a marked recovery in mechanical performance. These findings indicate that BFRP wrapping offers an effective and economical approach to the maintenance and reuse of railway timber sleepers.