Probabilistic Seismic Risk Assessment of Mizoram State, India
摘要
The Indian subcontinent is among the most densely populated, and a large part is highly susceptible to seismic activity. The northeast India region, which lies between the Indo-Burmese arc (East) and the Himalayan arc (North), is regarded among the world's most complex tectonic plates and lies in a highly seismically active zone. Hence, this paper aims to perform seismic risk analysis for the Mizoram state using an elliptically smoothened gridded seismicity model. Further, to account for epistemic uncertainty, logic tree architecture is used in ground motion prediction equations (GMPEs). To assess the seismic hazard at the given rock site (Vs30 = 760 m/s), a total of five GMPEs for the subduction zone of Indo-Burma are used. To analyze the seismic risk, exposure data of the building is taken from the 2011 housing board census. Buildings present in the state are assigned to different categories based on construction material, and seismic vulnerability models are mapped to each category. This classification enables a nuanced understanding of the diverse risks associated with different types of structures. Lastly, the openquake calculator is used to calculate the seismic risk in various matrices, such as loss exceedance probability curves and average annual losses. Furthermore, a comparison with the risk estimated using the guidelines from current and proposed codal provisions from Indian Standards is also made as part of this work. The results in the present study are key steps towards promoting resilience and readiness in the face of seismic hazards, laying the groundwork for informed decision-making by relevant authorities.