Novel in situ method for fast determination of bridge pier displacements during push-over tests

Taiwan is located in an area where frequently changing weather conditions threaten the lives and properties of its residents. With global warming, concentrated rains and extreme weathers bring about more frequent flash floods and debris flows, and destroy more bridges. This study describes the first ever full-scale experiment to determine the lateral displacements of abandoned bridge piers during push-over tests. In addition to cable position transducers and a LVDT, a high speed 3D terrestrial laser scanner was placed in the riverbed to scan the test pier, the reaction pier, and the reference steel frame. The results showed that not only can the laser scanner detect and measure the pier displacements at specific points, but it can also provide the displacement measurements of the entire test pier from top to bottom, thus generating more measurement data of the pier deformation behavior for further analysis than the cable position transducers or the LVDT alone. Other benefits of using the laser scanner include the determination of the relative displacements between the test pier and the reaction pier and the 3D realistic visualization of the experiment site. It is believed that the terrestrial laser scanner can play important roles in future large-scale structural experiments.