Earthquakes are one of the most destructive natural phenomena. In the 20th century earthquakes were responsible for 1.87 million deaths and approximately $2.935 trillion (adjusted to 2012) total economic losses. Between 1980 and 2009 earthquakes affected approximately 61.5 million people worldwide, resulting in approximately 400,000 fatalities and leaving at least 16 million people homeless. Between 1998 and 2009 earthquake events resulted in approximately 19,000 fatalities and direct economic losses of approximately €29 billion across Europe. While structural remediation/rehabilitation of the built environment against earthquakes is a widely studied subject, the knowledge on foundation improvement to mitigate the effects of earthquakes on buildings and critical infrastructure is limited, with existing remediation techniques being very invasive and costly. This is particularly true when the earthquake results in liquefaction of the soil. Earthquake induced liquefaction occurs when soil strength and stiffness decrease as a result of increased pore water pressure in saturated cohesionless materials during seismic ground motion. Because of liquefaction soil behaves like a liquid and not a solid, resulting in large deformations at the ground surface that causes buildings and lifelines to sink, settle or fall (overturn).
Over the past 42 months, the LIQUEFACT project has studied the potential impacts that an earthquake induced liquefaction event could have on Europe and produced technical guidance on how to quantify the risks at a local (micro-zonation) or site specific scale. LIQUEFACT has compiled a database of past liquefaction occurrences and integrated this with a macro-zonation map that shows the level of risk of earthquake induced liquefaction across Europe. LIQUEFACT has also developed new techniques for modelling the damage caused by an earthquake induced liquefaction event on structures and infrastructures and evaluated three ground mitigation interventions (horizontal drains, vertical drains, and induced partial saturation) to improve soil performance. LIQUEFACT has integrated all the above into a Resilience Assessment and Improvement Framework (RAIF) and software solution (the LRG) for evaluating potential mitigation interventions to improve structure/infrastructure and community resilience. Together the
