Field studies of the natural and built environments using large mobile shakers

An overview of some field studies that are now possible due to the development of five large mobile shakers and associated field support vehicles is presented. Development of this equipment has been funded by the U.S. National Science Foundation. Characteristics of the five mobile shakers are briefly reviewed. Four types of testing involving the mobile shakers are discussed. Examples of noninvasive shear-wave velocity (VS) profiling using surface-wave methods with active sources or combined with active and passive sources over depths from 10 to 1000 m are presented. Deep downhole seismic profiling with controlled-waveform compression and shear waves to > 400 m is presented. Two in-situ parametric studies are discussed. The first study involves evaluating the shear-modulus nonlinearity of a cemented alluvium. The second study involves evaluating pore-water pressure generation in loose saturated sand. Finally, the effects of dynamic and slow-cyclic loading on soil-foundation-structure interaction using scaled structural systems are presented.