Obtaining the surface PGA from site response analyses based on globally recorded ground motions and matching with the codal values

Destructive moderate to major earthquakes across the globe have highlighted various possible forms and extent of damages. Subsoil properties play a vital role in controlling the actual damage scenario. Induced effects such as liquefaction and landslide are also the functions of surface ground shaking. In the present work, site response analyses based on equivalent linear model using SHAKE2000 are attempted to assess the surface scenario. In the absence of recorded data at the site under consideration, globally recorded ground motions from Pacific Earthquake Engineering Research database are considered. Site response analyses results show variation in amplification factor as high as 7.4. Post-filtering of the analyses results has been proposed in this work considering the site condition as well as the design requirements. Based on the filtering, the above value of amplification factor has been reduced to 2.5. This reduction will considerably affect the design values and subsequently the construction cost. In addition, the value of surface peak ground acceleration proposed in this work matches closely with the earlier published literature as well as the codal provisions.