CFRP筋体外加固铁路预应力混凝土简支梁桥设计及试验研究

采用自主研发的CFRP筋体外预应力加固桥梁锚具装置(包括锚固装置和张拉装置),对铁路预应力混凝土简支梁桥进行加固设计和现场试验。针对CFRP筋体外预应力加固特点,计算预应力损失和CFRP筋配筋面积,验算加固桥梁的反拱、正截面强度、抗裂性、抗剪性以及挠度等;在此基础上,对大秦铁路线某16m预应力混凝土简支梁桥进行了现场加固试验。结果表明:该文提出的加固方法适用于实际铁路桥梁加固,加固后符合现行铁路相关规范和混凝土结构加固设计规范要求,且桥梁的受力性能得到明显改善。

THE DESIGN AND TEST STUDY ON PRESTRESSED RAILWAY CONCRET BEAM BRIDGE STRENGTHENED BY EXTERNALLY DRAPED CFRP TENDONS

Regarding to the reinforcement of the prestressed railway concrete beam bridge,an anchor device developed by the authors is adopted and applied in both the design and field test.The device is composed of anchors and tensioning devices,which is designed to strengthen the bridge by externally draped CFRP tendons.According to the characteristics of CFRP tendon prestressed reinforcement,prestress losses and CFPR reinforcement area are calculated,while the antiarch,normal section strength,crack resistance,shear resistance and deflection are checked,etc.Then,filed test was carried on a 16-m long prestressed railway concrete beam bridge of Daqin railway.The results show that the reinforcement method is suitable for practical railway bridge reinforcement,while the requirements of current railway codes and design codes for strengthening concrete structures are fulfilled and the mechanical behavior is improved significantly after reinforcement.