Vibratory Plate Loading of Compacted and Instrumented Field Soil Beds

Field scale studies of foundation and plate vibrations, particularly in the nonlinear domain, are vital to improving understanding and validating analytical and numerical efforts. This paper describes the development of an experimental program to investigate the dynamic signature of a rigid plate and of the soil during surface plate vibration of compacted soil beds. Nineteen testing sequences were performed on 1.2-m deep prepared soil test beds embedded with miniature triaxial accelerometers. Various vibratory loading frequencies (10–60 Hz) and amplitudes (up to 220 kPa contact stress) were applied via a 0.45-m-diameter plate to the prepared test beds. The paper describes the load testing frame, the preparation of free field partially-saturated sand test beds, and the placement of triaxial accelerometers within the soil. Plate and soil acceleration profiles are presented for the range of applied forcing frequency and amplitude levels involved. The nonlinear soil-compactor system response is analyzed and presented in both the time and frequency domains to present key features observed during testing.