Resilient and sustainable steel frame with innovative post-tensioned connections and rate-dependent passive dampers for multi-hazard resistant design

This project will investigate a steel moment-resisting frame with innovative post-tensioned beam-column connections and rate-dependent (elastomeric or fluid) passive dampers for multi-hazard resistant design. The overall research objectives are: a) decrease in the construction cost, rapid assembly on-site, simple deconstruction, adaptability, and potential for reuse of structural members; b) enhanced progressive collapse resistance and reparability against a sudden loss of column simulating bomb blast or heavy vehicle collision (terrorist attacks); and c) easy inspection/repair allowing almost immediate return to service after a strong (design) earthquake as well as increased life safety under a very strong (maximum credible) earthquake.

The project will develop fundamental knowledge, design details, and design methods for the proposed steel frame by conducting integrated design, analysis and experimental research. In particular, the project will: a) develop design details and criteria for an innovative post-tensioned connection; b) experimentally evaluate the behaviour of the post-tensioned connection with large-scale monotonic and cyclic tests simulating a loss of column scenario and seismic loading, respectively; c) evaluate the seismic performance and the progressive collapse resistance of the proposed steel frame; d) develop a practical seismic design procedure for the proposed steel frame in the context of the European seismic design standard-Eurocode 8; and e) compare the costs and sustainability aspects of constructing the proposed steel frame and a conventional steel moment-resisting frame.

The project will go beyond the state-of-the-art in the field of minimal-damage structural systems; significantly improve the UK's competitiveness in structural engineering; meet important national priorities related to sustainability and resilience; and align with EPSRC's global, economic and societal challenge themes.

Impact on:

Society: Bomb blast, heavy vehicle collision and large earthquakes are extreme loading scenarios which can result in building collapse, loss of function of life-line infrastructure (hospitals, communication centers, government buildings, etc), homeliness, and, loss of life or injuries. The steel frame solution to be researched can eliminate these social risks by enabling enhanced progressive collapse resistance against a sudden loss of column and a very low probability of sideway collapse under the maximum credible earthquake. In addition, the proposed steel frame solution provides decrease in the construction cost, rapid assembly on-site, simple deconstruction, adaptability and potential for reuse of structural members, and, shall contribute to sustainability and the green economy. The project can also protect the strong political relations of the UK worldwide since extreme loads have caused in the past political instabilities in countries where the government failed to deal effectively with the management of disasters.

Economy: Apart from the social risks, extreme loads result in enormous economic losses related to repair costs, loss of building occupation, business interruption, or building demolition due to irreparable damage. The project can eliminate these economic losses by avoiding (or enabling easy repair of) damage. Disasters in the UK or elsewhere (e.g., seismic regions) can result in loss of production, manufacture and other services, and can directly affect UK imports, exports and supply chain due to the globalized market and economy (The Telegraph 15/05/2011: Japan Earthquake: The companies most affected by the Disaster). UK consultants have designed innovative structures both in the UK and abroad, e.g., the damage-free Maison Hermes building in Tokyo incorporating rocking columns and dampers was designed by Arup. The proposed research on resilient minimal-damage structures will significantly contribute to the competitiveness of stakeholders in the UK. The project will also provide several UK and European industries with a characterized technology to increase their markets worldwide. Steel manufactures and contractors, producers of elastomers (or other smart damping materials) and companies producing post-tensioning solutions will see significant benefits. The project will help the insurance industry to increase their markets worldwide by using more reliable input (i.e., the proposed frame has a predictable reliable performance) into catastrophic risk models (e.g., www.rms.com).

Knowledge: The project presents major intellectual challenges by going beyond the state-of-the-art in the field of resilient and sustainable structural systems. The project combines new technologies for structural design (i.e., post-tensioning and passive energy dissipation) and will raise major international interest by developing a steel frame that incorporates novel structural details and addresses major disadvantages of existing structural systems.

People: The project will provide professional development to a PhD Student (PGRS) and a Post-Doctoral Research Assistant (PDRA). The PGRS and PDRA will obtain high-level skills in performance-based design, numerical modeling, large-scale experimental testing, structural dynamics, steel structures design, passive dampers and minimal-damage structures. In addition, they will acquire technical writing, presentational, management and research dissemination skills, and, will have the opportunity to network with a consortium of six academics, consultants and industrial partners. This training will help them to embark on a successful career in academia or industry. In addition, the project will increase awareness within the general public, educate undergraduate students and contribute to the Continued Professional Development of structural engineers and industrial partners.