Publication

Abstract : The collapse of the Darahara tower during the 2015 Nepal Gorkha earthquake, without much damage to the vernacular buildings, reminds us again to revisit the kind of pulse motion that basins like the Kathmandu basin, Los Angeles basin, or Kanto basin on which Tokyo is situated. In this work, we create various numerical models addressing the geometry and shape of the basin relative to a causative fault and synthesize ground motion at the basin centre and bedrock (basin edge). In numerical simulations, we also have the possibility of creating a completely new model without a basin to mimic the bedrock ground exactly as the location of the basin centre of the model with basin. We characterize the pulse periods of basin and bedrock for various dimensions, shapes and materials by focusing on the Sd x Sv product spectrum as indicated in (Mimoglou et al., 2014) it is quite straightforward to see long-period pulses ranging from 5-10 sec, apart from the short period pulses. These pulse periods within basins would be important in understanding the expected pulse-like shaking at various urban agglomerates lying on top of basins, for preparedness.