Numerical investigation of liquefaction-induced settlement and instability on earth dams

Abstract

Liquefaction is a phenomenon in which soil loses its bearing capacity, large settlements occur, and lateral spreading and failures may be caused. Numerous studies around the world have shown that liquefaction occurs in the alluvium foundations of earth dams. In this paper, methods of assessment and numerical analysis have been used to assess the Shourijeh reservoir dam liquefaction. According to the latest criteria, it was observed that by considering the acceleration of the maximum credible earthquake (MCE) level, the alluvial foundation of the Shourijeh dam is liquefiable in some areas. The dynamic analysis and liquefaction modelling based on linear equivalent analyses have been used. By analysing the sliding block and sliding circles based on the limit equilibrium method and the Newmark sliding block analysis, the stability safety factors of slopes for the Shourijeh dam after the earthquake have been investigated for three different earthquakes and various states of reservoir water level. The results, in addition to providing helpful information regarding the performance of earth dams against liquefaction and its effects, have shown that the settlements caused by liquefaction in the studied dam are not so large that they would cause extensive damage of the dam at the MCE level.