The design live load of
railway is divided into common railway and high-speed railway separately inKorea.
Accordingly, the Korean design specification of railway specifies the impact
factor for common railway and high-speed railway respectively. The impact
factor for high-speed railway is based on Eurocode. Since the impact factor
criteria inKoreawere established by adopting those of the Eurocode and without dedicated
investigation relying on research results reflecting the domestic
circumstances, thorough examination should be implemented on these criteria.
Therefore the evaluation of impact factor based on field tests is required.
Both dynamic and static vertical displacements are necessary to compute the
impact factor. The dynamic response can be obtained from the measurement of
deflection of the bridge slab crossed by the firstKoreahigh-speed train (KTX, Korea
Train eXpress) running at high-speed. The main difficulties encountered are in
obtaining static response because static response corresponds to the response
of the bridge when the train remains immobile on the bridge or crosses the
bridge at speed slower than5 km/hr. This study
introduces the static response derived by applying the moving average method on
the dynamic response signal. To that goal, field measurements was conducted
under train speeds of5 km/hr and ranging
from100 km/hr to300 km/hr
on Yeonjae Bridge located in the trial section of the Gyeonbu High-Speed
Railway Line before its opening. The validity of the application of the moving
average method is verified from comparison of measured static response and
derived static response by moving average method. Moreover, evaluation is
conducted on the impact factor computed for a bridge crossed by the KTX train
running at operational speed.