In-Situ Damage Detection of Wharf Structures Using Local Damage Factor

Significant research has been conducted in damage detection using dynamics-based technique. But simultaneously determining the presence, severity, and location of damage using the existing damage detection methods still faces some challenges. In this study, a new structural damage detection method called Local Damage Factor (LDF) is presented, and it is capable of determining the presence, severity, and location of a structural damage at the same time. By including the dynamic information of the local intact structure in the LDF method, the influence of structural nonlinearity, imperfection, and system noise is considered, so that the accuracy of damage detection is improved. The effectiveness of the LDF method in damage detection is evaluated using an experimental study of a 3-D steel frame structure, and the experimental results indicate that the method can effectively determine the presence, severity, and location of a saw cut crack in one of the pillars in the frame. The LDF method is effective in a way that it can eliminate the nonlinear severity effect of structure itself and ambient noise which are contained in the intact structure. As an implementation of the proposed technique in practice, damage detection of a wharf structure is presented using the LDF method, and the crack damage in one of concrete piles in the wharf is successfully detected. The successful detection of damage in the 3-D frame and the wharf demonstrates that the proposed local damage factor (LDF) technique can be effectively and efficiently used in damage detection. Further, in-situ damage detection of the wharf pile indicates that this proposed technique can be used to detect damage in large structures in the real time.