Soil Instruments Ltd has been involved in the supply and installation of geotechnical monitoring instrumentation to the Moroccan Government’s dam building program since 1990.

The most recently completed (December 2002) contract is the CID-designed and SGTM-built Barrage Aït Messaoud, part of the Dchar El Oued complex, on the river Oum Er Rbia at the northern foot of the Middle Atlas Mountains near Khenifra. The main component of the dam is a 33m high, 160m long, concrete gravity structure, with an adjoining 180m long clay core earth-fill embankment, designed for flood control, water supply, hydropower generation and irrigation.

The instrumentation installed within the main dam foundation includes vibrating wire piezometers, rod extensometers, hanging and inverted manually and automatically read pendulums. During the concrete pour, embedded thermocouples monitored internal concrete temperatures. Over 25 manually read triaxial jointmeters monitor movement between adjoining concrete plots in the galleries and at the crest. Automatically read V-notch weirs monitor flow from the gallery drainage system.

The earth-fill embankment has two instrumented profiles of vibrating wire piezometers installed at three levels with three 40m deep inclinometers monitoring the stability of the right bank abutment

All vibrating wire instruments and pendulums are cabled back to an instrument house where they are monitored via a data acquisition system designed and installed by Soil Instruments