九跨预应力混凝土连续梁的环境振动试验与模态分析

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.

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

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.