Vibration-based Damage Detection in Historic Quay Walls: A Full-Scale Test in Amsterdam

In the Netherlands, more than 1700 km of historic quay walls exist. Many of those structures, which consist of a masonry wall, a timber floor, timber beams, and timber piles, are approaching the end of their service life. In order to prevent future failures (such as the collapse of the Grimburgwal), it is essential to assess their structural condition. In this research, a vibration-based monitoring campaign was conducted to investigate whether vibration-based monitoring can be applied to assess the condition of quay wall structures. During the experiment, controlled structural damage was imposed on a quay wall along the Nieuwe Herengracht in Amsterdam (constructed in 1861) by isolating a segment of the structure and sequentially cutting part of its timber foundation piles. Imposing controlled structural damage to this quay wall was feasible, as the Municipality of Amsterdam started the renewal of this quay wall immediately after the experiment. Acceleration measurements, complemented by inclinometer data and total-station displacement measurements, were collected to identify and compare the dynamic features of the structure (i.e., natural frequencies, mode shapes, and damping ratios) before and after isolating the section, as well as before and after cutting part of the timber foundation piles. Based on this comparison, this study will show whether vibration-based monitoring can detect variations in the quay wall's dynamic behaviour due to damage (i.e., common quay wall failure mechanisms induced during the experiment) and whether this information can be used as a proxy for structural health assessment.