当主梁开裂严重,承载力大幅下降或不能承担车辆的荷载时,用其他方法无法解决根本问题,就需要更换主梁,使之恢复或提高原桥的承载力。本文对装配式梁桥换梁法加固方法进行探讨,结合某桥的加固案例进行分析。计算结果表明,加固后能够大幅度提高承载力,且桥梁恒载明显小于原桥。证明这种方法加固效果可行、有效。 When the main girder cracking serious, bearing capacity dropped significantly or can not bear the load of the vehicle, other methods can not solve the fundamental problem, you need to replace the main beam, so that the original bridge to restore or improve bearing capacity. In this paper, we discuss the reinforcement method of the beam-bridge assembly beam changing method and analyze the reinforcement case of a bridge. The calculation results show that the reinforcement can greatly improve the bearing capacity, and the bridge load is obviously less than the original bridge. Prove that this method is effective and effective.