Macrogravity measurements on reduced-scale models of geotechnical structures

■ ABSTRACT Following a historical summary of the measurement techniques used on a geotechnical centrifuge, this article will offer a broad overview of the measurements performed on reduced-scale models of geotechnical structures tested in the LCPC centrifuge over the past twenty-plus years. The reducedscale model has been fi tted with sensors intended to withstand a macrogravity fi eld, equal to 100 times the acceleration of gravity on earth, generated by centrifuge rotation. The successful operations of these sensors under conditions of increasing weight can never be guaranteed. To proceed, a set of sensor verifi cation procedures were adapted to the macrogravity environment. The sensors introduced were either purchased, and thus adapted to test conditions, or output from a special development effort in association with a method specifi c to macrogravity (i.e. optical or non-destructive measurements, miniaturized sensors). In all cases, a technological monitoring and metrological assessment step proves necessary. This article will present the specifi cities of equipment used to conduct measurements (data acquisition systems, sensors) as well as the miniaturized tests carried out during rotation (penetrometer, vane test, pressure meter, T-Bar, Falling Weight Defl ectometer). Some of the devices produced will also be exhibited (robot, earthquake simulator).