Characterization of Dynamic Soil-Pile Interaction by Random Vibration Methods: Experimental Design and Preliminary Results
Preliminary results are presented for full-scale vibration tests of piles using random vibration methods and a new servo-hydraulic inertial shaker testing system. Separate tests of vertical and coupled horizontal-rocking modes as well as hybrid multi-mode tests were performed on two steel HP 10x42 piles installed to a depth of 20 ft at a site containing soft clays. One pile was tested in the natural soil profile while the other had a cement deep soil mixed (CDSM) improved zone near the surface. Three excitation techniques were examined using a range of forcing intensities to determine the optimal testing configuration. The multi-modal vertical-eccentric test format was investigated as an efficient alternative to traditionally separate tests having vertical or horizontal forcing. Design of the experimental testing system is described, followed by a preliminary comparison of results from the various test configurations. Measurements indicate that the new excitation and instrumentation systems were successful in stimulating and capturing the broadband dynamic response of the soil-pile system for use in validating and calibrating advanced 3D computational continuum models.