Abstract: To prevent collapse of retaining walls, a wavelet packet frequency band energy spectrum analysis was performed for the virtual impulse response function of a retaining wall under the effects of excitation based on the wavelet packet frequency band energy spectrum theory. A damage feature vector spectrum and a damage alarming index were created. On the basis of both the spectrum and the index, a three-level damage alarming method was worked out for retailing wall structures. To verify the feasibility and effectiveness of this alarming method, vibration tests on a pile plate retaining wall were performed. Results show that damage state of the retaining wall can be alarmed via the damage feature vector spectrum, partial damage location of the wall can be alarmed via the alarming index trend surface, and damage intensity of the wall can also be alarmed via the quantitative relationship between the damage intensity and the alarming index.

Key words: retailing walls, virtual impulse response function, damage feature vector spectrum, damage alarming index, three-level damage alarming method