介绍了用力锤激励铁路运行实际桥梁模态分析的特别试验。试验采用了新技术 ,一、弹性聚能力锤延长了力的激励时间 ,使激励力的能量聚集在低频处 ;二、使用了变时基 (Varied-Tim e- Base)传递函数模态分析方法 ,极大提高了大型结构的传递函数的分析精度 ,从而使锤击法进行大型土木结构的模态试验成为可能。本文是国内外首次利用锤击激励进行的铁路运行实际桥梁模态分析的成功试验 ,具有一定的科研和应用价值 The special test of practical bridge modal analysis by using hammer to stimulate railway operation is introduced. The experiment adopts a new technique. Firstly, the elastic polyhedron hammer prolongs the excitation time of the force, so that the energy of the excitation force is concentrated at the low frequency. Second, the Varied-Tim e-Base transfer function modal analysis method , Which greatly improves the analytical accuracy of the transfer function of large structures and makes it possible for the hammer method to perform modal testing of large civil structures. This paper is the first successful test of practical bridge modal analysis of railway operation by hammering excitation at home and abroad, and has certain scientific research and application value