Forced vibration of full-scale wall-backfill system

A full-scale vibration test is conducted to measure the low-amplitude dynamic characteristics of a reinforced concrete cantilever wall-backfill system. Measurements during a frequency sweep are recorded along the wall length. From these measurements, resonant frequencies are identified, along with the corresponding response configurations that depict variation in motion along the wall length. In general, the wall and adjacent backfill zone are observed to move together in-phase. Farther away from the wall, out-of-phase wall-backfill motions are measured at higher resonant frequencies. Finally, retaining systems of uneven height, such as wing walls, are shown clearly to exhibit three-dimensional (3D) seismic response characteristics.