Abstract:

On 3 November 2023, a moment magnitude (MW) 5.7 (Local Magnitude, ML 6.4) earth-quake struck the western region of Nepal, one of the most powerful seismic events since 1505 in the region. Even though the earthquake was of moderate magnitude, it caused significant damage to several masonry buildings and caused slope failures in some regions. The Field reconnaissance carried out on November 6-9 following the earthquake conducted the first-hand preliminary damage assessment in the three most affected districts- Jajarkot, West Rukum, and Salyan.

This study covers the observed typical structural failures and geotechnical case studies, from the field study. In order to have a more comprehen-sive understanding of the earthquake damage observed, the paper examines the seismotectonic setting and regional seismic activity in the country. The observations of earthquake damage suggest that most of the affected buildings were made of stone or brick masonry without seismic consideration, while most of the reinforced concrete (RC) buildings remained intact. Case histories of damaged buildings, the patterns, and the failure mechanisms are discussed briefly in this paper. Significant damage to Khalanga Durbar, a historical monument in Jajarkot, was also observed. Medium to large-scale landslides, and rockfalls were recorded along the highway. The motorable bridge in the Bheri River suffered from broken bolts, rotational movement at the expansion joint, and damage to the stoppers. The damage observations suggest the implementation of the building code could have lowered the impact in the region. The geological and geographical analysis of the regions indicates that the local population faces a potential threat of subsequent disasters arising from earthquakes and earthquake-induced landslides. This underscores the necessity for proactive measures in preparedness for future disasters.

Status:

Ongoing

Team:

Mandip Subedi, Keshab Sharma, Rajan KC, Jibendra Misra, Apil KC, Kabin Lamichhane, Prabin Acharya, Shikshita Bhandari