预应力碳纤维板强化改造重载铁路桥梁成套技术

Complete Technology for Strengthening Heavy Haul Railway Bridges with Prestressed Carbon Fiber Plates

为满足我国铁路桥梁加固和重载强化改造工程的需求,以30 t以上轴重重载铁路改造技术科研项目为依托,开展预应力碳纤维板加固重载铁路桥梁技术的研究以及预应力碳纤维板组装件等产品的研制、加固体系设计、模型梁加固试验、原梁加固试验等,解决了碳纤维板材的夹持、张拉和锚固等技术难题,提出了加固设计的原则及指标、产品质量检验以及施工验收的技术要求,形成了预应力碳纤维板加固重载铁路桥梁的成套技术.研究结果表明：研制的采用波形夹片式锚具和楔形夹片式锚具的碳纤维板组装件具有优异的力学性能,其锚固效率（组装件强度与材料强度的比值）均大于0.95;在200MPa疲劳应力幅作用下,经历200万～400万次疲劳加载后,其锚固效率仍大于0.95;100和1 000 h的应力松弛率分别为1.156％和1.600％.通过对6m模型梁和32 m预应力混凝土梁加固试验,验证了预应力碳纤维板加固重载铁路桥梁成套技术的可行性和可靠性,加固效果满足重载铁路设计要求,并已成功应用于朔黄铁路桥重车线上20 m简支梁的加固.

To meet the demand for strengthening and reconstructing railway bridges for heavy-haul railway, based on the research of the reconstruction project aiming at heavy-haul railway with the axle load over 30 t, the study on the technique of strengthening railway bridge with prestressed carbon fiber plate was performed, so were the development and verification on product invention, strengthening system design, model beam experiments and full scale beam experiments. The technical issues of the clamping, tension and anchorage of carbon fiber plate were solved. The technical requirements on the principles and indexes of strengthening design, product test and acceptance check of construction were proposed. The packaged technology for strengthening heavy haul railway bridges with prestressed carbon fiber plates was developed. Results show that the carbon fiber plate assembly with the wave form anchor and cuniform anchor invented behaves excellent in mechanics, whose anchoring efficiency coefficient （i. e. the ratio of the intensity of assembly to the base material） is over 0.95. Under the fatigue load with 200 MPa in stress increment, after 2 million to 4 million times of load cycles, its anchoring efficiency coefficient is still over 0. 95. The slack coefficient remains 1. 156% after 100 h and 1. 600% after 1 000 h. The packaged technology has been proved feasible and reliable by the experiment on 6 m span model RC beam and 32 m span prestressed concrete beam. The strengthening effect meets the demand for heavy-haul railway design. The packaged technology has been applied successfully on 20 m span simply supported beam of heavy-haul line of Shuo-Huang Railway.