Large-scale experimental dataset of seismic pounding and SSI in bridge deck–abutment–backfill systems (ERIES: PoundBack2)

This dataset contains results from a large-scale experimental campaign investigating deck–abutment seismic pounding and the associated soil–structure interaction (SSI) mechanisms in bridges with seat-type abutments. The experiments were conducted at the UKCRIC Soil–Foundation–Structure Interaction (SoFSI) Laboratory, University of Bristol, within the framework of the ERIES – Engineering Research Infrastructures for European Synergies (2022–2026) programme, funded by the European Union’s Horizon Europe framework (Grant No. 101058684). The ERIES PoundBack2 project is designed to provide a mechanistic understanding of the coupled deck–abutment–backfill system under repeated seismic impacts. In particular, the study focuses on how backwall–stem wall connection behaviour and damage evolution influence impact forces, energy dissipation mechanisms, and the extent of dynamically mobilised backfill. The experimental programme addresses several fundamental challenges in current seismic bridge modelling, including: Quantification of impact forces and coefficient of restitution (CoR) during deck–abutment pounding Identification of the dynamically participating backfill mass Characterisation of damage evolution at the backwall–stem wall interface under repeated impacts Assessment of the influence of connection behaviour on system-level SSI response Provision of high-quality experimental data to support Eurocode-aligned, performance-based seismic assessment The tests were carried out in a large-scale controlled physical model that explicitly incorporates full-height compacted granular backfill, enabling direct observation of soil mobilisation and wave propagation phenomena. The SoFSI soil pit has internal dimensions of 6 m × 5 m in plan and 4.15 m in depth, providing realistic boundary conditions for plane-strain behaviour. Two purpose-designed backwall configurations were implemented to represent distinct design philosophies and limit states: Sliding–shear (sacrificial) configuration, characterised by reduced interface capacity and relative displacement at the backwall–stem wall connection Monolithic (flexure-governed) configuration, designed to develop a plastic hinge at the backwall base and enforce rotational continuity Impact loading was applied using a pendulum system, delivering controlled and repeatable velocities representative of seismic demand. The dataset (Version 1.0) focuses on tests conducted at a target impact velocity of 0.5 m/s, selected to characterise the dynamic response of the system within the relevant seismic range. The following configurations are included as CSV files: Sliding–shear (sacrificial) configuration – 0.5 m/s impact velocity (test date: 24 Oct 2025) Monolithic (flexural) configuration – 0.5 m/s impact velocity (test date: 8 Dec 2025) All data are provided in the following engineering units: Time: seconds (s) Displacement: millimetres (mm) Acceleration: g Strain: microstrain (µε) Force: kilonewtons (kN) The dataset is accompanied by two supplementary documents: The instrumentation layout (Poundback2_Instrumentation_layout.pdf), detailing sensor types, locations, and channel naming conventions The wall reinforcement drawings (Poundback2_Wall_Design_Drawings.pdf), providing formwork and reinforcement details for both backwall configurations, the stem wall, concrete hinge, and impact head.