九跨预应力混凝土连续梁的环境振动试验与模态分析

Ambient vibration testing and modal analysis of a prestressed concrete continuous girder bridge with 9 spans

介绍了深圳市松岗高架桥———九跨预应力混凝土连续梁桥的现场环境振动试验的概况.利用频域中的峰值法(PP)和时域中的随机子空间识别法(SSI)分别进行桥梁模态参数识别;利用ANSYS建立了全桥三维有限元模型并进行了理论模态分析,理论计算和实测结果吻合较好.此类测试与分析有助于桥梁的状态评估与维修加固.

An ambient vibration field - testing under traffic - induced excitation on a prestressed concrete continuous girder bridge was carried out. The bridge with 9 - spans is located in Songgang County, Shenzhen, Guangdong Province. The peak picking （PP） method in frequency domain and the stochastic subspace identification （SSI） method in time domain are used for the output- only modal parameter identification. The 3 - D finite element models （FEM） are constructed by using ANSYS program and a theoretical modal analysis is then performed to generate natural frequencies and mode shapes in the 3 - orthogonal directions. It is further demonstrated that the results from the FEM agree well with the field tests, which can serve as a referenced model in the seismic evaluation or retrofit of the bridge.