effects of groundwater level fluctuation on superstructure’s seismic behaviour in dhaka city

During an earthquake, site surface ground motion is different in terms of amplitude and frequency content in comparison to the bedrock motion. these changes are due to dynamic response of subsoil layers. this dynamic behaviour is a function of strain level of soil and pore presser level. in dhaka city, during the monsoon seasons, because of high precipitation, theground water level goes up in some areas. this, in turn, may result in a higher pore water pressure during an earthquake, which consequently filters some of the high frequency content of the earthquake motion and amplifies some other frequencies. in this study, the effects of such changes (both in ground motion frequency content and in amplification factor) and their effects on superstructure’s behaviour are calculated.