Reaction Spectrum Comparative Analysis of Seismic Performance of 62 m CFST Bridge with Curved-String Truss before and after Reinforcement

Table 1

The first 10-order natural vibration characteristics of the bridge before reinforcement.

Modal number	Frequency (Hz)	Cycle (s)	Mode shape characteristics
1	1.741	0.574	Transverse first-order vibration of the main truss
2	2.982	0.335	Vertical vibration of the bridge deck
3	3.329	0.300	Torsional vibration of bridge deck
4	3.335	0.300	Transverse second-order vibration of main truss
5	3.487	0.287	Vertical vibration of the bridge deck
6	3.492	0.286	Full bridge torsion of the first-order vibration, vertical vibration of the bridge deck
7	3.808	0.263	Vertical vibration of the bridge deck
8	4.123	0.243	Full bridge torsion second-order vibration, vertical vibration of the bridge deck
9	4.216	0.237	Vertical first-order vibration of the whole bridge
10	4.408	0.227	Vertical vibration of the bridge deck