Advanced sensing in geotechnical centrifuge models

The ability to measure and record physical phenomena is paramount to geotechnical centrifuge modeling. Advanced sensing techniques provide additional methods for system identification and acquiring experimental data. The Geotechnical Centrifuge Research Center at Rensselaer Polytechnic Institute has developed and implemented three advanced systems that complement traditional sensors. These include (1) an in-flight high-speed camera and lighting system for dynamic testing; (2) tactile sensors that measure 2-D soil pressure; and (3) a bender element system for measuring mechanical wave velocities. The high-speed camera captures the motion of targets installed on the surface of centrifuge models. Tactile pressure sensors measure soil pressure on subsurface structures and are used to determine at-rest, active and passive lateral earth pressures. The level of saturation and small-strain shear modulus are quantified through the detection of primary and secondary waves using bender elements and custom software.