Scour & Shake: preparing for testing on the large table

A large aluminium and rubber container with support frames mounted to a large shaking table. Next to it is a dumbell-shaped concrete and aluminium specimen mounted vertically.
Specimen mounted to the table next to the shear stack for fixed base testing.

We’re almost ready to start testing on our large shaking table, for the first of four projects being undertaken in SoFSI as part of the wider European-funded ERIES project. This project, in partnership with a multi-national user group, aims to investigate the effect of river scour on the seismic performance of bridge foundations.

The first stage of testing is a fixed-base test of the specimen mounted directly on the shaking table. This will help to characterise the model so we understand it’s resonant frequencies.

We will then mount the model in sand in our shear stack (laminar soil box) for the main set of tests in April. For these we’ll subject the model to white noise and seismic motions, before excavating increasing depths of sand from around the foundation to simulate scour of the sediment.

A dumbell-shaped specimen made of concrete masses and aluminium bar mounted vertically on a steel surface. Sensors are attached to the central bar.
The 1:15 scale model of a bridge pier, with concrete foundation section, aluminium bar selected to model the stiffness of the prototype bridge pier, and concrete top mass to simulate the load from the bridge deck.

 

First research project underway

Construction is complete on our first research project at the Soil-Foundation-Structure Interaction Laboratory. This project, which makes use of our 4m deep soil pit, has been under construction since late May. Researchers aim to better understand the interaction between the abutment and backfill of integral bridge abutments.

We are now at an exciting stage in the project, having completed the physical construction, and are now preparing instrumentation ready for testing in August. In total, over 100 tonnes of concrete and sand form the experimental set-up, and this has been a great opportunity to pilot the use of the pit, and hydraulic actuator for the first time.

  • A 4m deep pit, with precast concrete blocks being positioned to form a retaining wall