Geotechnical Instrumentation & Monitoring
The performance of geotechnical structures (e.g., foundations, retaining walls, embankments) is, in many cases, monitored for purposes of both short-term and long-term safety, for evaluations of performance-based-design and as part of the implementation of the observational method. Exponent provides instrumentation and monitoring services tailored to the client’s specific application and needs. Exponent has the capability of installing instrumentation and monitoring output in real time, on-site or remotely. Exponent provides meaningful engineering and scientific analysis that can provide the basis for confident decisions about the performance of structures. Exponent works with clients to provide recommendations for proper use of the performance data and threshold levels as they relate to the operation and overall safety of the structure.
Exponent has considerable experience with various types of instruments, sensors and measurement methods, which covers multiple applications:
- Monitoring of horizontal and vertical movement of structures and surroundings via inclinometers, tiltmeters, PK nail markers LiDAR and topographic survey and photogrammetry.
- Interpreting soil properties based on cross-hole and down-hole seismic testing.
- Groundwater monitoring via piezometers and observation wells.
- Condition assessment via crack gages and strain gages.
- Stress, temperature, soil suction and moisture measurements via load cells, thermometers, tensiometers, relative humidity tests and moisture sensors.
- Vibration monitoring via accelerometers, geophones and microphones.
- Video monitoring via web-cameras.
Exponent owns various types of instruments and sensors including accelerometers, geophones, tiltmeters, string potentiometers, thermometers, pressure sensors, microphones, video cameras, crack gages and others. Additional specialty sensors can be purchased and integrated into Exponent’s data acquisition system.
Data Logging and Remote Sensing
For remote sensing and data logging projects, Exponent consultants utilize a modular data acquisition system that can be adapted to the project’s specific needs. The system uses NI-DAQmx modules to perform analog to digital conversion, allowing nearly all types of sensors to be used with the system. Signals can be sent via wired or wireless connection based on project requirements. The data is then collected and processed on a laptop computer. Remote data access is provided via a 3G/4G data card installed on the laptop computer, or any available internet connection.
Exponent’s system is ideal for projects that require distributed data acquisition. The system is portable and can be powered by a variety of power sources, including solar panels. It can be installed in open areas with up to one mile line of sight using a high-gain wireless antenna.