To diagnose damages within retaining wall structures

based on impulse response function and virtual impulse response function

the damage feature vector spectrum was created and a damage identification index was proposed. Based on the damage feature vector spectrum and damage index

a damage diagnosis method for retaining wall structures was proposed. In order to verify the feasibility and validity of this damage diagnosis method

vibration tests on a pile plate retaining wall were performed under impulse excitation and ambient excitation

the damages within the wall were diagnosed via the damage feature vector spectrum and damage index. The tests results show that the damage state of the wall can be sensitively distinguished by the damage feature vector spectrum

damage location of the wall can be validly diagnosed through the damage index trend surface

and damage intensity of the wall can be quantitatively identified through the quantitative relationship between the damage index and damage intensity. Due to the influence of excitations

the stability of the damage index which is based on the impulse response function is poor relatively under impulse excitation

while the stability of the damage index which is based on the virtual impulse response function is much better under ambient excitation.