Pseudo-dynamic rupture implementation and earthquake engineering consequences of simulated ground motion in NCT Delhi (India) caused by Mwmw8.2 Nahan Himalaya seismic gap earthquake

This paper presents the physics based ground motion synthetics and its earthquake engineering consequences in the National Capital Territory (NCT) Delhi, India due to the Mw8.2 scenario earthquake on the Nahan segment of the western Himalaya. In order to fulfill the aim, a state-of-the-art pseudo-dynamic rupture is implemented in a 3D fourth-order staggered-grid viscoelastic time-domain finite-difference code. The ground motion is simulated in a frequency bandwidth of 0–2.5 Hz at the basement level at 158 locations of the NCT Delhi. The computed transverse component of velocity time series at the basement level is numerically transferred to the free surface taking into account the rheological parameters of the sediment deposit. Upon first inspection, the estimated range of peak ground acceleration, between 0.017–0.12 g, indicates that all the buildings in the NCT Delhi will remain safe in the event of an Mw8.2 Nahan earthquake, provided they are constructed in accordance with Indian building codes. But, the computed acceleration response spectra (Sa) depicts that some of the high-rise buildings of the NCT Delhi may suffer minor damage to collapse under partial or complete double resonance condition due to Sa exceeding the DBE and MCE levels. The obtained range of pseudo-spectral displacements (Sd) reveals the need of performance-based design for high-rise buildings in the NCT Delhi, so that they can withstand under partial or complete double resonance condition during the occurrence of Nahan earthquakes. The developed contour maps of Sa and Sd at different periods can be used for the retrofitting and forced-based and displacement-based designs of the high-rise buildings.