Abstract
In 2004, Caltrans installed a monitoring system (GPS sensors) at Carquinez Bridge (Highway I-80) to obtain real-time displacement measurements of bridge motions under traffic, wind, and seismic loads. However, since the data file is huge, approximately 1 GB a day, it takes a long time to download the text file for analysis, and common tools such as Excel cannot open these large files. The Web-based system will have three main features (Capture Real-Time Stream, Identify Special Events, and Record History records). First, it will capture the constant stream of sensor data generated by RTK-GPS processing software (RTKNav) and filter the data based upon an assessment of data quality. Second, the system will calculate relevant statistical measures (e.g. mean, standard deviations) to identify significant measurements (e.g. during earthquakes, windstorms). Third, the system will store average hourly and daily measurements in a database and maintain full time history records. The system is built on a WAMP stack (Windows, Apache, MySQL and PHP). Once the system is complete, it will be deployed to a server located at Carquinez Bridge(Highway I-80) toll plaza.