对西瓜洲大桥加固改造过程中的不同状态进行环境激励的振动测试,对振动信号采用时域中的随机子空间识别方法进行实验模态分析,探讨了模态参数的变化规律。文章所识别出来的模态参数精度高,可以作为施工过程中各阶段有限元模型修正的依据,以便更好地进行桥梁加固改造过程中的施工控制。 Vibration test of environment excitation for different states of watermelon bridge during the process of reinforcement and reconstruction is carried out. Experimental modal analysis of vibration signal using random subspace identification method in time domain is carried out, and the change rule of modal parameters is discussed. The high precision of the modal parameters identified by the article can be used as the basis for the finite element model amendment in all stages of the construction process in order to better carry out the construction control during the reinforcement and reconstruction of the bridge.