These are normally dynamic loads caused by earthquakes, ship impacts and wind. When feasible, design parameters are checked with full scale static loading testing. The traditional static testing is very costly, dangerous, time consuming, and limited to loads that can be generated by a hydraulic jack. Dynamic load testing methods do not provide direct measurements, induce high accelerations, and load-displacement behavior is controlled by the action of stress waves. The piston contains a load cell for measuring force and a laser sensor to measure displacement.
Solid propellent is burned inside the piston to generate a gas pressure.
The piston is mounted horizontally on a foundation using a hemispherical bearing to minimize any eccentricities in the load. The accelerated masses generate a force equal to the mass times acceleration. A patented system of motion sensors placed horizontally in inclinometer casing embedded in the foundation measures the lateral acceleration of the foundation at various depths. Strain gages embedded in the foundation measure the strain at those same depths. This allows the engineer to calculate soil response which then can be used to create computer model of the soils and foundation.