LESSONS FROM THE SEISMIC PERFORMANCE OF PILE-SUPPORTED BRIDGES AFFECTED BY LIQUEFACTION DURING THE M8.8 2010 MAULE CHILE EARTHQUAKE

Abstract

Ground failure case studies have been the source of the most important advances in geotechnical earthquake engineering over the past 50 years. Documented case histories from the 2010 M8.8 Maule Chile earthquake will, if carefully studied, further advance this field. The 2010 M8.8 earthquake in Chile showed that liquefaction-induced soil-foundation-structure interaction problems are still far from being completely understood. The observed damage and partial collapse of pile-supported bridges like Juan Pablo II, Llacolén, Tubul, La Mochita, and Raqui, is most likely due to the effects of liquefaction-induced lateral and vertical ground displacement, which often causes large ground deformations that impose kinematic loads on the pile foundations. In this paper, simplified back-analyses regarding the seismic performance of bridges Mataquito, Juan Pablo II, and Llacolen are presented. The bridges have been selected not only because clear evidence of liquefaction was found at their respective locations, but also because their seismic performance was very different, ranging from little to negligible damage to a larger and more distributed level of damage.