Perris Dam Subsurface Movements and Water Pressures

Geodaq provided instrumentation and monitoring services during construction of test excavation areas at the toe of Perris Dam located in Riverside County, California.

• Geodaq manufactured and installed four in-place inclinometers to depths of about 170 feet in standard 2.75-inch diameter casing.
• Geodaq also installed 10 electrical resistance piezometers to monitor groundwater levels at various locations at the dam.
• A total of 14 monitoring stations collected readings from inclinometers and piezometers and transmitted the results in real-time to a server computer for storage in a MySQL database.
• The real-time monitoring system collected and transmitted readings at intervals ranging from every 5 minutes to every 2 hours depending on the nature of the work being accomplished.
• Three levels of threshold criteria were established for the project whereby different project team members would be immediately notified if any changes in calculated displacements or water levels exceeded threshold levels.
• This provided a monitoring system that was active even when construction personnel were not at the site like weekends, holidays, and at night.