Repeated simulated earthquakes in a mechanical device called a centrifuge are second only to the real thing for developing reliable ways of analyzing seismic safety in the event of the destructive phenomenon known as "soil liquefaction," according to organizers of a conference held this week at UC Davis. Funded by the National Science Foundation, a four-year international collaboration culminated this week with the first systematic review of the strengths and weaknesses of the most popular and most advanced earthquake engineering methods currently used around the world. The meeting established that centrifuge models can be used, as they were in this project, to test the accuracy of the current methods used to design structures that will withstand liquefaction. "The liquefaction problem affects the stability of all existing infrastructure systems -- transportation, dams, waterfront-retaining structures," says UC Davis engineering professor Kandiah "Arul" Arulanandan, head of the four-year project and an organizer of the conference.