Earthquake and flood are two major natural threats to the bridge in Taiwan. Seismic force and flood-induced scouring effect typically cause tremendous damage to the bridge, resulting in their shorter service life. To reverse this natural course of damaging, there is a crucial need for a high-level performance of seismic design technology of bridges. And it is critical to conduct the experimental validation of the devised design of bridge pier system that connects to the foundation specimen. Due to space limitation, however, this type of experiments is difficult to carry out.

Recently, the NARL's National Center for Research on Earthquake Engineering (NCREE) obtained permission from the Directorate General of Highways, Ministry of Transportation and Communication (MOTC) to perform an in-situ pushover testing of an old bridge in Yi-Lan County in northeast Taiwan. The old Niu-Dou Bridge consists of two parallel bridge units, constructed in 1963 and 1995, respectively. And the test was to push the circular column of the new Niu-Dou Bridge completed in September 2010 with two actuators mounted on the wall pier of the old bridge and two supporting frames side by side as a reaction wall. It was to evaluate the seismic performance of the full-scale that bridge with non-ductile design details, including one specimen in the condition of fully covered caisson foundation, and the other one with 4 m scouring depth.

The NARRL-NCREE’s in-situ experiment of seismic performance of the old Niu-Dou Bridge on November 30, 2010 was witnessed by nearly hundred experts from MOTC, engineering companies, and universities. And the interdisciplinary team of engineers and scientists drawn from various universities in Taiwan will integrate numerical response analyses with pushover experiment for studying the hybrid failure mechanism of the existing bridges, and proposing new design and evaluation methodology for new bridges.