Performance of highway bridges during high intensity earthquakes

Abstract

Just when it was thought that it would take many years before a severe earthquake like the Hanshin-Awaji (Kobe) earthquake wrecked havoc, another catastrophic earthquake struck the central region of Taiwan in 1999, killing over 2,350 people and injuring 10,000 people. The earthquake incurred tremendous damage to infrastructure mostly highway bridges and buildings caused by fault ruptures, near-fault strong motion and inadequate unseating prevention mechanism. Damage to bridges included fault rupturing, collapsed spans, flexural and/or shear failures, liquefaction, slope failures, soil settlement, and landslides. Most urgent in mitigating the bitter experiences of such high intensity earthquakes is the revision of seismic design code to include elasto-plastic design for high intensity earthquakes taking into account dynamic response of structures, as well as improvement on the design of minor but important elements such as shear keys and concrete stoppers to prevent unseating of girders. In recognition of limited knowledge on structural response induced by near-fault earthquakes and fault ruptures, "easy to repair and reconstruct" concept should be a priority in bridge design and construction, and research should be intensified.


Journal of Civil Engineering, JKUAT (2001) Vol 6, 117-132