DYNAMIC SOIL-STRUCTURE INTERACTION

Geotechnical engineering is at its most unpredictable and uncomfortable when variable or dynamic loads on foundation systems are significantly higher than in the static or 'at rest' condition. Resilient infrastructure requires that the duration of bounce-back, the time to restore functionality after extreme events, is minimised. Codes attempt to deal with this using combinations of load and resistance or material factors that are sometimes drawn from fatigue or repetitive loading experience. However these can result in design solutions that either fail due to a lack of appreciation of the controlling parameters or that are uneconomic and overcautious. The lecture will examine soil-structure interaction under catastrophic collapse, wave loading, high speed trains and dense urban seismic loading using examples drawn from real-world installations. It will show how economy in design can be driven using unified soil-structure interaction modelling through advanced numerical analysis in which rate effects are explicitly considered. Recent improvements in the visualisation of foundation behaviour under extreme events enables us to articulate more effectively extreme event scenarios across disciplines and project stakeholders. The lecture will provide a springboard from which resilient, performance-based design methods can be developed and improved, with the promise of feedback from digital data analytics.