Bridge Monitoring and Damage Detection

(Pictures)

Bridge and highway monitoring for Caltrans in Rapid-Set concrete panels on Highway 99 above Second St.  Five panels are used in the study (two of which are approach slabs - adjacent to the bridge itself).  Long-term and short-term performance of the highway panels is measured against dynamic loads that induce mechanical vibrations and strains; effects of thermal strains are measured due to daily and seasonal temperature changes.  Loads are generated via passing trucks and cars.  Accelerometers measure the mechanical vibrations of the bridge deck, which are then correlated to the potential damages in the rapid-set and 'conventional' concrete panels.  Recommendations about the benefits and health-state of the Rapid-Set panels is made.  The help and support of Caltrans is acknowledged, especially that of Mark Der Matoian, Robert James, and Alan Vong.  The help of FCI Constructors is also appreciated in this project, especially that of Zeb Lemke. 

Demolition of an existing concrete panel                    Night-time instrumenting with flashing truck in the background!!            Approach slab instrumentation (on the rebar mat)

                                                                                ... this is one cool picture!!!

This work is not possible without devoted graduate students like Kittinan Dhiradhamvit

         Geokon model 3900 strain gages were used for concrete embedment.                                    ... and into the night we toiled away!!

Our instrumented non-approach panel ready for the pour... after another all-niter!!                ... here's a close-up!!

Here are some more pictures, including the Rapid-Set panel pour and finish.

The approach slab rebar mat being lifted into place...                                                                    ... the final layout

Who's that!!!???                                                                                                Kittinan is in the lab doing a performance testing the Campbell Scientific  

                                                                                                                         datalogger.  Strain gauges (Geokon 3900 and VW Slope Indicator) and

                                                                                                                         CrossBow accelerometers are connected to the datalogger to ensure

                                                                                                                         everything works before going out to the bridge site.

A couple of repairs... all part of the job requirements!!