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The Necessity of Highway Bridge Instrumented With Earthquake Early Warning And Monitoring
System
Early detection of highway bridges' earthquake damage or degradation prior to local failure can prevent
"runaway" catastrophic failure of the bridge system. In the event of an earthquake, the rapid detection of
catastrophic failure of a strategic bridge can allow early and effective response by highway officials in
rerouting traffic and avoiding an otherwise difficult situation. The large physical sizes of the bridges
necessitate an extensive array of different
sensors and appropriate technologies for data
acquisition/reduction for rational health monitoring applications. The bridge earthquake damage
monitoring systems should also be designed for a long life under severe environmental conditions. The
system should be able to automatically detect, locate and assess structural damage anywhere within the
bridge system, and to communicate the status (alerting) to responsible authorities. At its simplest
application, the threshold exceed anywhere in the bridge is monitored and an alarm is provided if pre-set
threshold levels have been exceeded. This alarm may be used to automatically divert the traffic if it
indicates damage due to earthquake, explosion or impact.
THE PROPOSED AUTOMATED EARTHQUAKE E-MONITORING SYSTEM IN TAIWAN
Taiwan Central Weather Bureau (CWB) can now routinely obtain earthquake information in one minute
after the occurrence of an earthquake using this new algorithm. In order to take full advantage of this
capability, four automatic information broadcast media, namely, E-mail, World Wide Web, FTP server
and pager system, have been configured to receive and transmit automatically the earthquake
information from the CWB seismic monitoring system.(Ref 1). See Fig. 2. This new automatic
earthquake information Warning and Monitoring system will enable the CWB to disseminate
information about felt earthquakes even more quickly and widely than its current practice through fax
and paper reports.
Lessons Learned from Early Earthquake Warning And Health Monitoring Systems
In all types of bridge health monitoring system, the early earthquake warning and monitoring system has
a basic framework consisting of (1) a broad spectrum of monitoring techniques, (2) a mechanism for
collating and evaluating this disparate data, (3) a routine for converting the relevant data into a
prediction or a forecast of an impending hazard, and (4) a system for issuing the relevant warning to
those at risk.