APPLICATION OF SMALL-REAM CENTRIFUGE IN GEOTECHNICAL RESEARCH

Geotechnical centrifuges are used world wide to investigate structures whose behaviour is strongly dependent on the mechanical properties of soil. Although centrifuge research is cheaper than real scale testing it is still expensive. The costs can be reduced significantly if the tests are performed in a small centrifuge. Using miniature equipment and advanced monitoring systems, many geotechnical problems can also be modelled in a small centrifuge. The preparation of a test takes relatively little time, so that the time interval between idea and results is short. An additional advantage is that small soil samples can be reproduced very accurately, so that slight modifications of the test models can be visualized, A beam centrifuge with a diameter of two metres has been developed at the University of Delft. The design concept was to keep the device as simple as possible and to keep the weight of the samples so low that they could be carried by one person. To enable the performance of a large variety of tests, several miniature devices were developed, such as: a sand sprinkler, a two dimensional loading system, an air supply system, a water supply system and a vane apparatus. The limitation of space for sensors was neutralized by using image processing techniques to measure the deformation of the soil in flight. Several research projects have been conducted, e.g.: sliding behaviour of spudcans, stability of dikes during wave overtopping, blowouts, stability of embankments during widening, buckling behaviour large diameter piles, suction ode installation, uplift capacity buried pipe lines, simulation earthquakes, etc..