Structural Performance Monitoring and Evaluation of Scoured Bridges under Dynamic Actions

ERIES: Scour & Shake

Dataset Description

This dataset presents results from a comprehensive experimental campaign investigating the dynamic response of bridge piers on embedded caisson foundations under scour conditions. The project was conducted at the UKCRIC Soil-Foundation-Structure Interaction (SoFSI) Laboratory at the University of Bristol, as part of the project Scour & Shake: Structural Performance Monitoring and Evaluation of Scoured Bridges under Dynamic Actions, within the project framework ERIES: Engineering Research Infrastructure for European Synergies (2022–2026), funded by Horizon Europe (Ref: 101058684-HORIZON-INFRA-2021-SERV-01-07).

The experimental programme focused on: (a) the effectiveness of vibration-based methods for scour identification, (b) the accuracy of available numerical modelling techniques, and (c) the effects of scour remedial measures in improving seismic performance. The tests were performed using a 4.8×1.0×1.2m³ equivalent shear beam box on a 6×4m², 50-tonne biaxial shaking table. The soil container was filled with 950mm of densely pluviated silica sand, underlain by a 40mm rubber layer to simulate deep soil conditions. Two model piers were tested:

- A slender (flexible) model, representing a tall pier with a long-span bridge;

- A stiff (squat) model, simulating a shorter pier with a lighter deck.

The piers were constructed using rectangular steel sections, with steel top masses connected by angle brackets. The caisson foundations were built from cylindrical steel sections, filled with concrete to achieve the target mass, and externally coated with glued sand to realistically reproduce interface friction.

Each pier was initially subjected to fixed-base tests, for modal identification. Then, the piers were placed in the soil container and the following scour scenarios were investigated:

- No scour (caisson fully embedded)

- Low scour (caisson exposed up to 1/3 of its depth)

- High scour (caisson exposed up to 2/3 of its depth)

- Remedial measures, involving gravel infill in the scour hole (slender specimen only)

Each setup was subjected to white noise tests with increasing amplitudes from 0.01 to 0.50g for modal identification, as well as a series of seismic ground motions corresponding to low and high seismicity. In total, over 250 tests were conducted. Fixed-base tests were performed on 27th June 2024, and full soil-structure interaction tests during the week commencing 15th July 2024.