Finite Element Safety Analyses of a Geosynthetic-Reinforced Dam Under Seismic Impact

摘要

In geotechnical practice the analysis of safety against failure of embankments and dams exposed to earthquakes is usually performed by conventional slip circle analyses or other analytical "rigid body" methods using equivalent quasi-static forces. In contrast e.g. the German code DIN 19700 ,,Dam plants - Part 11: Dams" demands dynamic calculations for dams higher than 40 m. However, no indications are given how to perform such dynamic analyses. The issue can be of interest for smaller but sensitive dams as well. The paper presents a FEM based procedure for such cases. The FE analyses enable a realistic modeling of the dam, the subsoil and the seismic excitation. An example of a geosynthetic-reinforced reservoir dam with a waterproof geomembrane is given based on a real project. Geometries, soils and geosynthetic reinforcement parameters, loads, constitutive models, and specific assumptions are described. Relevant results are presented and discussed together with specific issues concerning the geosynthetics and recommendations and conclusions are given.