ABSTRACT
Radical Concrete Technology. Edited by R K Dhir and P C Hewlett. Published in 1996 by E & FN Spon, 2-6 Boundary Row, London SE1 8HN, UK. ISBN 0 419 21480 1. ABSTRACT. In July and August of 1994, Taiwan was invaded by several aggressive typhoons. Those typhoons brought heavy floods, and the floods scoured the piles of Chung-Sa Bridge, so that the piles at spans No. 15-17 and No. 35-39 were exposed. The Taiwan Area National Freeway Bureau (TANFB) took the strengthening action immediately by putting gabions around the exposed piles to strengthen the stiffness of the exposed piles. This paper focuses on the seismic capacity evaluation of the strengthened Chung-Sa Bridge by means of in-situ ambient vibration measurements and finite-element simulation. Our research shows that the maximum allowable scouring depth of piles at Chung-Sa Bridge is 6.8 m in the site condition at spans No. 35-39, after strengthening the exposed piles by putting gabions around the exposed piles. The condition of the strengthened Chung-Sa Bridge is still on the safe side in accordance with the requirements of the “Seismic Design Specification for Highway Bridges” of Taiwan. Keywords: Bridge, In-Situ ambient vibration measurement, Natural Frequency, Pile Scouring, Seismic Dr Yeou-Fong Li is a Project Section Leader of Bridge Inspection and Evaluation Division of JOIN Engineering Consultants. His majors are focus on structural dynamics, spectrum analysis and in-situ ambient vibration measurement. Mr I-Chang Chen is Director of Planning and Design Department of Taiwan Area National Freeway Bureau. He is in charge of the maintenance and widening projects of Chung-Shan Freeway at Taiwan.
