OBJECTIVES:
Provision of access to the following infrastructure(s):
Seismic Testing Research InfrastructureSeismic Testing Research Infrastructure

Name of the infrastructure and its installations:
UKCRIC National Facility for Soil Structure Interaction (SoFSI) and EQUALS

Installations:
1: 6x4m shaking table (SoFSI), 2: 6x5x4m Soil Pit (SoFSI), 3: 3x3m Shaking Table (EQUALS)

Location (town, country) of the infrastructure:
Bristol, UK

Web site address:
https://sofsi.bristol.ac.uk

DESCRIPTION OF THE INFRASTRUCTURE:
The University of Bristol (UoB) is a research-intensive institution in the UK. The Earthquake and Geotechnical Engineering (EGE) research group is world leading, hosting a unique multimillion pound earthquake engineering laboratory equipped with several shake table earthquake simulators, a soil pit testing configuration, strong floors and a reaction wall. The SoFSI/EQUALS RI is supported by a primary group of eighteen senior academics, led by Prof. Anastasios Sextos (Head of Research Group – Academic Lead of the RI) and Prof. George Mylonakis (Chair of Soil-Structure Interaction, PI of the previous SERA project offering Transnational Access to European research groups), with very broad experience across earthquake engineering, soil-structure interaction, structural dynamics and infrastructure resilience. They form part of a larger, multi-disciplinary group of academics (see Administrative Form) specializing in advanced dynamics and materials from across the Civil, Aerospace, Mechanical Engineering, and Non-Linear Dynamics & Control fields that support the Facility. The primary academic group has supported around 150 external users over the past 15 years through TNA programmes (including more than 30 in the framework of the previous SERA project). SoFSI/EQUALS is also supported by ten, highly experienced, postdoctoral research assistants, who will offer day-to-day support for the users, including design of the experimental programmes. Four experienced technicians provide specimen fabrication and manufacturing as well as shaking table operation support. A fully equipped manufacturing workshop is also available.

The large-scale experiments of this proposal will be executed in the SoFSI/EQUALS Research Infrastructure that includes the new £12m UKCRIC National Facility for Soil-Foundation-Structure Interaction (SoFSI) and the long-established EQUALS laboratory of the University of Bristol, UK. This Facility integrates structural and geotechnical engineering for soil structure testing and fills key gaps in our understanding which cannot be resolved using conventional, smaller scale, laboratory tests or prototype observations. The SoFSI/EQUALS RI will enable the European TA users (and beyond) to deliver a unique, high value, capability for de-risking investments in innovation and development, for example in life-extension techniques for existing infrastructure or the application of new materials and devices.

The SoFSI/EQUALS RI comprises four installations (three of which are offered for TA, namely 1-3):

1. a 6m x 4m Biaxial Shaking Table with a 50t capacity, capable of meeting BELLCORE test standards with a peak acceleration at 2g and maximum frequency of 50 Hz. The installation is equipped with two laminar, flexible, shear boxes for geomechanics testing. One of these is 6 m long, 1.5 m deep and 1 m wide; the other is 1.5 m long, 1.0 m deep and 1 m wide (installation located at SoFSI).
2. a 6 m x 5m Soil Pit and a depth of 4 m (total volume of 120 m³) with flexible capability for saturated and unsaturated soil. Two (2) 1 MN pseudostatic actuators (of 1000 mm stroke) and one (1) 1 MN dynamic actuator (of 500 mm stroke) are available to be mounted on the adjacent strong floor. Smaller dynamic actuators (50 kN, 300 mm stroke, up to 50 Hz) can be mounted on bespoke reaction frames for specific experiments. A 1.5 m trench allows for testing buried specimens at multiple levels (installation located at SoFSI).
3. a 3 m x 3 m, 6DOF Shaking Table supported by 8 hydraulic actuators. The table can carry up to 15 tonnes and (depending on the loading) can reach acceleration levels up to about 5g with peak displacements of ± 150mm. The platform can accelerate horizontally up to 3.7 g with no payload and 1.6g with a 10t payload. Corresponding vertical accelerations are 5.6g and 1.2g respectively. Peak velocities are 1.0 m/s in all translational axes, with peak-to-peak displacements of 300 mm. A large database of recorded earthquake records can be applied, or synthetic motions can be readily created. Extensive instrumentation is available, including up to 256 data acquisition channels. It is surrounded by a strong floor and adjacent strong walls up to 15 m high (installation located at the University main Campus).
4. the Hexapod: a 1 m x 1 m, high performance (g) multi-axis simulation table with a 800 kg capacity, capable of a peak acceleration of 10 g (installation located at SoFSI).
   The shaking tables are accompanied by a set of servo-hydraulic actuators that can be configured to operate in conjunction with the shaking table’s strong floor and reaction walls, providing a highly adaptable dynamic test facility that can be used for a variety of earthquake and dynamic load tests.

EQUALS shaking table (installation 4, left), overview of the new SoFSI laboratory (installations 1-3, middle and right).

Services currently offered by the infrastructures:
The SoFSI/EQUALS RI has decades of established experience in experimental, computational and hybrid assessment of the response of masonry steel and concrete buildings, the use of discrete damping elements in building structures, soil-structure interaction, cable stayed, integral, long-span and special bridges, base isolation systems, multiple support excitation, nonlinear self-centering structures, dams, reservoir intake towers, retaining walls, advanced composite strengthening systems, embankments and retaining walls, conventional railway and high-speed rail (HS2) configurations, offshore wind turbine foundations, nuclear industry applications as well as lifelines (water, waste water and natural gas pipelines). The above expertise guarantees high quality support of TNA across a range of multi-disciplinary research fields.
A special feature of the SoFSI/EQUALS RI is its capability for ‘hybrid simulation’, where part of the structural system of interest can be emulated by a numerical model embedded in the digital control system, while only a sub-component need be tested physically. The shaking tables are ones of the few in the world that enable participation of remote users in experiments via high performance video conferencing and, where appropriate, direct interactivity with test and data acquisition equipment. Data and video can also be streamed in real time to remote users for use in off-line analyses. SoFSI/EQUALS is also newly connected to Bristol Is Open (BIO), the University’s new living laboratory research infrastructure comprising a dedicated high performance programmable fibre optic and wireless network around the city centre, overlain by an innovative City Operating System (CityOS). Previous successful collaboration with the University of Patras provides the credentials for geographically distributed and hybrid experimentation among remote sites within the consortium.

DESCRIPTION OF WORK:
Modality of access under this proposal:
The stages for offering user access to the SoFSI/EQUALS Research Infrastructure and its installations involve (a) the opening of the call, (b) feedback to the potential users while preparing their proposals, (c) proposal review (see final section) and (d) continuous support to ensure high quality delivery of the foreseen curiosity-driven research (see next section).
A typical project lasts approximately 12-15 calendar months (depending on the installation and the problem studied), including 3-6 months for the definition of the experimental programme and the design of the specimens to be tested (or the wider testing configuration in case of hybrid testing), 3 months for construction, 1 month for instrumentation, 2 months for shaking table calibration and specimen testing, and 3 months for post-processing the results. Users are expected to attend in person unless there is a force majeure imposed by pandemic or other unforeseen situations. Projects may involve users from several institutions and countries from across Europe and beyond. An important part of the user experience, especially for the training of younger researchers, is their direct participation in the design, construction and execution of the tests. Each project is unique in its purpose and scope. For this reason, some users might visit the facility at several different periods of the project, and not just during the testing period.
Users will be given access to the SoFSI/EQUALS Research Infrastructure on an access day basis when the installations of the laboratory will be at their full service. The three installations run at different access costs, which are calculated on an actual cost basis. The cost of the two new SoFSI pieces of equipment (installations 1 and 2) is defined as an estimate of actual cost since they will formally initiate their operation on 1/1/22. Note that a pilot project already runs within the SoFSI premises, hence there is no risk in terms of shifting the formal opening date. Access days are materialized when the shaking table and its associated control and acquisition systems are occupied. A typical project is expected to require between 15 and 30 access days depending on the installation. More complex structural/geotechnical/hybrid projects may require longer access.

Support offered under this proposal:
The Facility has long-established experience in hosting scientific visitors and providing logistic care for transportation and accommodation as well as scientific support. Users will be accommodated in offices within the laboratory, where they will be exposed to a stimulating multi-disciplinary environment. They will have their own workstation, including a powerful PC equipped with a range of finite element software and mathematical tools including MATLAB and access to the Advanced Computing Research Centre that hosts the BlueCrystal high performance supercomputer. Users will be awarded the formal status of a Visiting Researcher for the duration of their project and will have access to the University’s social facilities, such as the libraries and a new sports hall. A user support team will be allocated to each user. This team will be supervised by a senior academic (not necessarily the PI and the Co-I’s). An experienced postdoctoral research assistant (PDRA) will be assigned to work with the user on a daily basis to develop and execute the test programme. Our expectation is to make each project a research partnership with the user.
The services that will be offered to the users are: (a) technical assistance in the definition of the test programme and design of the test specimens, (b) fabrication and instrumentation of test specimens, with appropriate training when required, (c) implementation of the hybrid testing, sub-structuring and multiple-support excitation techniques for the simulation of earthquake loading on large-scale structural systems, (d) access to the data repository system accessible via Internet, (e) assistance for the development of advanced numerical models, (f) the opportunity to collaborate with the other international partners of the project and (g) logistic support for organizing meetings and workshops. It is noted that given that 4 installations are offered for TNA, the SoFSI/EQUALS RI can support the concurrent development and testing of several experiments. The users will be also offered the opportunity to train on a small scale (table-top) setup for hybrid testing (twin to one at the University of Patras) which operates on the same method and software used for actual HS testing. Training videos and material will be made available through the project web portal.

Outreach to new users:

Outreach to new users involves the following activities:

• Development of a dedicated website (and associated social media channels) for creating awareness about the accessibility of the Research Infrastructure and its three installations, promoting the call for proposals as well as the research outcomes of the project with direct links to the parent website of the ERIES project.
• Quantification of the potential user’s interest by monitoring the website/social media activity and the number of proposals, new users/visitors and requests for future access.
• Close collaboration with the UKCRIC consortium in the UK that involves 13 nationally based facilities, 6 urban observatories and two affiliated laboratories to promote the model of the ERIES Transnational Access for implementation within the UK, across the ERA and beyond.
• Allocation of human resources for systematic announcements to international research websites, conferences and workshops about the facility accessibility.
• Promotion of the novel research outcomes to Code and Standards drafting committees and other administrative or strategic panels, local authorities and network end-users and operators (tailored to each specific project undertaken) as well as the scientific community and engineering professional community (by means of publications).
• The interest around the two new SoFSI pieces of equipment (installations 1 and 2) is guaranteed by the fact that one pilot project is already funded and running, while within only a few months of delivery, three different universities have already submitted proposals to funding agencies for a combination of installations together with UBRI.

Review procedure under this proposal:
For details on the TA evaluation process, please refer to Task 1.2 of WP1 and the process followed by the TA-SEP in particular.