Full-Scale Measurements and System Identification on Sutong Cable-Stayed Bridge during Typhoon Fung-Wong

Table 1

Natural frequencies and modal damping ratios of the SCB.

Vibration modes	1st sym L	1st sym V	1st sym T	1st anti-sym T
𝑓mf (Hz)	0.112	0.186	0.542	0.611
𝑓mn (Hz)	0.118	0.195	0.558	0.629
𝑓𝑐 (Hz)	0.107	0.185	0.544	0.603
𝜁𝑓 (%)	3.65	3.24	1.23	1.26
𝜁𝑛 (%)	2.73	2.41	0.80	0.85
𝐸𝑓1 (%)	−5.4	−4.8	−3.0	−2.9
𝐸𝑓2 (%)	4.5	0.5	−0.4	1.3
𝐸𝜁	25.2	25.6	34.9	32.5

Note: sym: symmetric; L: lateral; V: vertical; T: torsional; 𝑓_mf: frequency measured during Typhoon Fung-Wong; 𝑓_mn: frequency measured during normal wind; 𝑓_𝑐: calculated frequency based on FE method; 𝜁_𝑓: damping ratio identified during Typhoon Fung-Wong; 𝜁_𝑛: damping ratio identified during normal wind; 𝐸_𝑓1= [(𝑓_mf − 𝑓_mn)/𝑓_mf] × 100%; 𝐸_𝑓2 = [(𝑓_mf− 𝑓_𝑐)/𝑓_mf] × 100%; 𝐸_𝜁 = [(𝜁_𝑓 – 𝜁_𝑛)/𝜁_𝑓] × 100%.