Prof Alonso described how concepts and modelling techniques address the problem of estimating potential damage caused by the velocity and motion of landslides, once equilibrium is lost. He went on to explore the physical phenomena and deformation mechanisms which can lead to fast sliding velocities, the mechanism of thermal pressurization of pore water in the sliding surface and the criteria required to decide if rapid motion is likely to occur.
At the other extreme of landslide mobility, slow creeping motion is often found in natural and man-made environments and Prof Alonso considered how to determine their evolution in time and the risk of sudden acceleration, in particular the use of the computational tool known as the Material Point Method, formulated for a three-phase granular medium. He also reviewed rainfall-induced landslides in partially saturated soils as unsaturated slopes exhibit mixed diffuse-shearing failure modes.
The Lecture was followed by a dinner in the Queen’s Tower Room of the Sherfield Building at Imperial College, a prestigious occasion when the geotechnical community gathered to honour Prof Alonso and the BGA presented him with an engraved decanter as a momento of the event.
The BGA Chairman, Prof Stephan Jefferis then announced that the 58th Rankine Lecturer on 21st March 2018 would be Dr Nick O’Riordan, an Arup Fellow with over 30 years’ experience of ground-related risk management associated with contaminated and derelict land, earthquake and storm hazards and collapses of underground excavations; he has been the Global Geotechnics Skill leader for Arup since 2009.