The University of Colorado Boulder's geotechnical facility includes state of the art centrifuges used for research, industry design, and instructional purposes. The facilities include three geotechnical centrifuges. The largest of these centrifuges is a 400 g-ton centrifuge. In terms of g-ton capacity, this centrifuge is one of the most powerful in the world. It is capable of accelerating an 1815 kg payload to a maximum of 200 g in 14 minutes. The centrifuge is used for numerous research projects investigating the static and seismic performance of retaining structures and slopes, seepage mechanisms, contaminant transport, and offshore foundation structures. The 6 m radius of the centrifuge arm permits an essentially uniform g-level to be applied to the full height of the centrifuge model. The swinging-basket type centrifuge platform can support a container footprint of 1.2 m by 1.2 m. This platform can accommodate boxes with a height of 0.91 m, with a maximum headroom of 1.35 m for offset actuators and loading devices. One of the payloads is a loading frame that can be used to evaluate soil-foundation interaction. The centrifuge can be used to simulate earthquake motions in flight by utilizing a servo-hydraulic shake-table. The data acquisition system for the 400 g-ton centrifuge includes a NI PXI data acquisition system combined with a 12-slot SCXI chassis, with modules suitable for signal conditioning for LVDTs, strain-gauge-type sensors, accelerometers, capacitance-type differential pressure transducers, high speed cameras. Motor control capabilities are also possible to operate brushed electric servomotors, solenoids, and electronic flow valves. Camera acquisition software can be used to track deformation of points or planes. The 400 g-ton centrifuge includes 3 hydraulic rotary union lines which can be used to supply pressurized fluid to the centrifuge platform.
The University of Colorado at Boulder centrifuge laboratory also includes a 15 g-ton centrifuge, which has a symmetrical arm comprised of aluminum sections carrying swing-baskets at each end. The 15 g-ton centrifuge accommodates experimental payloads up to 0.45 × 0.42 × 0.60 m and can accelerate a payload of 140 kg up to 200 g. This centrifuge has been converted for use as either a centrifuge permeameter to investigate water and heat flow processes in unsaturated soil layers, or a 2-degree of freedom load frame for vertical and lateral loading of suction caissons.
The most recent addition to CU's centrifuge laboratories is the instructional centrifuge, housed in the undergraduate geotechnical laboratory. Although this centrifuge has been in operation since 1996, it was completely refurbished during the summer of 2004 to accommodate symmetrical swinging baskets, video data acquisition system, and a high performance AC drive motor. This centrifuge is primarily used as an instructional tool in undergraduate geotechnical engineering labs to introduce simple concepts of slope stability, active and passive earth pressure conditions, and bearing capacity taught in class.