Page 145 - Bridge and Highway Structure Rehabilitation and Repair

120 SECTION 1 ADMINISTRATIVE ISSUES

Figure 3.18 Failure of the Oakland Bridge.

Figure 3.19 Quebec Bridge collapse.

3. Growing traffic on our waterways is increasingthe probabilities of a barge/bridge collision
that canresult in a disaster.
4. Aging highway signage and high mast lighting (luminaries) are becoming structurally un-
sound, usually due to failingconnections, and are creating the potentialfor damage and loss
of life.
5. An evaluation of risk and a vulnerability rating based on inspections

3.20.3 Use of Effective Monitoring Methods
1. Underwater inspection or instrumentation as a bridge management tool: Figure 3.20 shows
visual monitoring followed by flood watch and follow-up monitoring of scour critical

bridges.
2. Use of modern techniques: The use of wireless and remote sensors enables the movements of

bridges to be monitored around the clock. This is most desirable in flood situations. Modern
sensors, when installed on scour critical bridges, minimize the possibility of sudden collapse
and serve as a warning for a bridge to be closed.
Modern techniques are further discussed in Chapter 9 on scour.
3. Investigating unknown foundations: Figure 3.21 shows the need for geotechnical procedures
in evaluating unknown foundations.