An Effective Method for the Determination of the Natural Frequency of piled Pier Segments through Impact Vibration Testing

The Impact Vibration Test (IVT) is an effective, accurate, and fast non-destructive evaluation method to indicate the technical condition of structures through the consideration of the health index. This index is the ratio of measured and designed natural frequencies in the absence of the original measured frequency. However, the determination of the natural frequency of the berth’s segments in both numerical and experimental approaches is expensive and time-consuming work. This motivated the present study to develop formulas that allow quick estimation of the natural frequency of the berth’s segments based on one of the horizontal frames under various conditions and cases. In order to execute this task, different wharves with various working levels, geological conditions, characteristics, and spring coefficients were examined. A case study for a wharf under a real incident is also provided to show the procedure and demonstrate its effectiveness. Interestingly, the natural frequency of the horizontal frame can be obtained quickly and simply in comparison with that of the berth’s segment. Therefore, the proposed formulas are expected to significantly enhance the efficiency of field IVT investigations.