ENGINEERS HAVE COMPLETED improvements to the Quiebranjano dam in Jaen, Andalusia, Spain, including replacing the original instrumentation with new gauges and monitoring devices.

Among the new elements installed at the 27-year-old concrete arch dam were vibrating wire piezometers, 3D crackmeters and displacement transducers for rod extensometers. Also installed were laser distance transducers for hanging and inverted pendulum systems, ultrasonic sensors for V-notch weirs, accelerographs and a complete meteorological station.

Each one of 154 sensors was connected by cable to one of 22 terminal boxes where data could be accessed manually. The signals from the sensors were also conduced from the terminal boxes to the data acquisition system, which comprised six Campbell CR10X dataloggers supporting 18 AM-416 multiplexers. The CR10Xs linked into a network via multidrop interfaces and coaxial cable to the monitoring station situated about 300m from the crest of the dam.

A desktop server installed in the monitoring station stores the acquired measurement every six hours for the sensors located in the dam. The measurements can be displayed, and over 400 different trend graphs can be shown and printed.