The 27th February 2010 earthquake in central and south of Chile was a very strong test for recently constructed geosynthetics reinforced soil wall solutions for bridge abutments. This 8.8 moment magnitude subductive earthquake caused severe damage to several traditional reinforced concrete walls for bridge abutments. However, no significant disturbance was found to these new geosynthetics reinforced solutions. For that reason, it is important to review the design and construction employed in these projects. To this end, a representative case located close to the epicentre is described and studied. Moreover, information is provided regarding the foundation soils, design and construction sequence of the geosynthetics reinforcement used for bridge abutments. The foundation soils were poor, corresponding mainly to marine and fluvial deposits close to the stream and mouth of the Andalien River. The analysis covers the verification of static external and internal stability as well as seismic external and internal stability. In addition, global static and seismic analyses are carried out. The methods used for the analyses are limit equilibrium and pseudo-static following recommendations of the FHWA. Results show that the design was adequate to cope with such a strong seismic event in terms of external and internal stability. By comparison, it was found that the use of piles prevented a global seismic failure of the geogrid reinforced soil walls for the bridge abutment. Final comments and remarks are presented related to design and construction which may explain the favourable performance of these geosynthetics reinforced structures under a strong subductive earthquake.
展开▼
