Building typologies and failure modes observed in the 2015 Gorkha (Nepal) earthquake
Nepal is one of the most earthquake-prone countries in the world, and at the same time is one of the most economically deprived. On 25 April 2015 mid-western Nepal was hit by the devastating Gorkha earthquake measuring Mw 7.8 with the epicentre located 76 km north-west of Kathmandu. The earthquake was followed by a series of aftershocks, with the most significant occurring on 12 May 2015 with Mw 7.3 and an epicentre located north-east of Kathmandu. The earthquake and the associated aftershocks resulted in the destruction of half a million buildings, leaving millions of people homeless and causing a loss of more than $3.5 billion (USD) to the housing sector alone. Approximately 9,000 people were killed and over 23,000 people were injured - mostly due to damaged or collapsed buildings.
A number of documents have been published pertaining to general observations following the 2015 Gorkha earthquake and aftershocks. Here the common building typologies and related failure modes observed during inspection surveys by the authors who were part of the various reconnaissance teams following the earthquakes are summarised. A brief background on the 2015 Gorkha earthquake is provided with an outline of the tectonic environment and seismological background of Nepal and a brief summary of previous earthquake activities in the region is presented. Common construction practices identified during the reconnaissance are illustrated and briefly explained to provide context to the observed earthquake damage, with an emphasis placed on unreinforced masonry (URM) building typologies and construction practices. Comparisons between URM building damage and published macro-element failure modes are provided using various photographic and schematic examples. Commonly observed failure modes and potential causes of failure are also highlighted for buildings constructed of reinforced concrete (RC) frames with masonry infill. A brief review of adopted temporary shoring techniques is also included.
Statistics (2015). “Nepal Disaster Risk Reduction Portal, Government of Nepal”. www.drrportal.gov.np. (Accessed 15/06/2015).
Saijo K, Kimora K, Dongol G, Komatsubara T and Yagi H (1995). “Active faults in south western Kathmandu basin, central Nepal”. Journal of Nepal Geological Society, 11 (Special Issue), 217-224.
Nakata T and Kumahara Y (2002). “Active faulting across the Himalaya and its significance in the collision tectonics”. Active Fault Research, 22: 7–16.
Sapkota SN, Bollinger L, Klinger Y, Tapponier P, Gaudemer Y and Tiwari D (2013). “Primary surface ruptures of the great Himalayan earthquakes in 1934 and 1255”. Nature Geoscience, 6: 71–76.
Techtree (2015) “Why Himalayan Region is Prone to Earthquakes”. http://www.techtree.com/. (Accessed 22/11/2015).
Washington Post (2015). “Nepal’s Earthquake: Mapping its Ripple Effect Across Asia”. https://www.washingtonpost.com/graphics/world/nepal-earthquake/. (Accessed 22/11/2015).
Srivastava1 HN, Bansal BK and Mithila Verma (2013). “Largest earthquake in Himalaya: An appraisal”. Journal Geological Society of India, 82:15-22.
UNDP (2009). “Nepal Country Report-Global Assessment of Risk”. ISDR Global Assessment Report on Poverty and Disaster Risk 2009. United Nations Development Programme, Kathmandu, Nepal. www.undp.org.np/uploads/publication/201010290938349 9.pdf. (Accessed 22/11/2015).
Rana BJ and Lall K (2013). “The Great Earthquake in Nepal (1934 A.D.)”. 1st English Edition. Kathmandu: Ratna Pustak Bhandar. ISBN 9789937330152.
Bilham R (2004). “Earthquakes in India and the Himalaya: tectonics, geodesy and history”. Annals of Geophysics, 47(2): 839-858.
Bilham R (2009). “The seismic future of cities”. Bulletin of Earthquake Engineering, 7: 839–887.
Bilham R, Gaur VK and Molnar P (2001). “Himalayan seismic hazard”. Science, 293: 1442–1444.
Ritzen Y (2015). Al Jazeera agency “Timeline: Nepal earthquakes”. http://www.aljazeera.com/indepth/interactive/2015/04/timeline-nepal-earthquakes-150425115801610.html. (Accessed 22/11/2015).
National Seismological Centre (2015). “Nepal Earthquake”. Department of Mines and Geology, Government of Nepal, http://www.seismonepal.gov.np. (Accessed 22/11/2015).
USGS (2015). “Map of Nepal Earthquake and Aftershocks”. United States Geological Survey. http://www.usgs.gov. (Accessed 15/06/2015).
NPC (2015). “Nepal Earthquake 2015: Post-Disaster Needs Assessment, Volume A: Key Findings Kathmandu”. Nepal Planning Commission, Government of Nepal. http://www.npc.gov.np/. (Accessed 22/11/2015).
Aydan O and Ulusay R (2015). “A Quick Report on The 2015 Gorkha (Nepal) Earthquake and its Geo-Engineering Aspects”. International Association for Engineering Geology and the Environment (IAEG), 26pp.
Goda K, Kiyota T, Pokhrel RM, Chiaro G, Katagiri T, Sharma K and Wilkinson S (2015). "The 2015 Gorkha Nepal Earthquake: Insights from Earthquake Damage Survey". Frontiers in Built Environment, 1. DOI: https://doi.org/10.3389/fbuil.2015.00008
Indian Standards (2002). “IS-1893: Criteria for Earthquake Resistant Design of Structures, Part 1, General Provisions and Building”. Fifth Revision. Earthquake Engineering Sectional Committee, CED.
NBCDP (1994). “Seismic Hazard Mapping and Risk Assessment for Nepal”. (UNDP Pro# Nep.88.054-21.03), Nepal Building Code Development Project Nepal, His Majesty‘s Government of Nepal, Ministry of Housing and Physical Planning, UNCHS Kathmandu, Nepal.
Bothara J and Brzev S (2011). “A Tutorial: Improving the Seismic Performance of Stone Masonry Buildings”. First Edition, Earthquake Engineering Research Institute, Oakland, California.
NZSEE (2015). “Assessment and Improvement of the Structural Performance of Buildings in Earthquakes - Section 10 Revision. Seismic Assessment of Unreinforced Masonry Buildings”. New Zealand Society for Earthquake Engineering, Wellington.
Russell AP and Ingham JM (2010). "Prevalence of New Zealand's unreinforced masonry buildings". Bulletin of the New Zealand Society for Earthquake Engineering, 43(3): 182-201. DOI: https://doi.org/10.5459/bnzsee.43.3.182-201
DPCM (2006). “Approvazione dei modelli per il rilevamento dei danni a seguito di eventi calamitosi, ai beni appartenenti al patrimonio culturale – scheda “Chiese” e scheda “Palazzi.””. Ministry for Cultural Heritage and Activities, Italy. G.U. n.55 del 07-03-2006-[In Italian].
Leite J, Lourenco PB and Ingham JM (2013). “Statistical Assessment of Damage to Churches Affected by the 2010-2011 Canterbury (New Zealand) Earthquake Sequence”. Journal of Earthquake Engineering, 17(1): 73-97. DOI: https://doi.org/10.1080/13632469.2012.713562
Lagomarsino S and Podestà S (2004). "Seismic Vulnerability of Ancient Churches: I. Damage Assessment and Emergency Planning". Earthquake Spectra 20(2): 377-394. DOI: https://doi.org/10.1193/1.1737735
Lagomarsino S. (2009). “Damage assessment of churches after L’Aquila earthquake (2009)”. Bulletin of Earthquake Engineering, 10: 73-92.
Carocci C (2011). “Small centres damaged by 2009 L’Aquila earthquake: on site analysis of historical masonry aggregates”. Bulletin of Earthquake Engineering, 10: 45-71 DOI: https://doi.org/10.1007/s10518-011-9284-0
D’Ayala D and Paganoni S (2011). “Assessment and analysis of damage in L’Aquila historic city centre after the 6th April 2009”. Bulletin of Earthquake Engineering, 9: 81-104 DOI: https://doi.org/10.1007/s10518-010-9224-4
Dizhur D, Ismail N, Knox C, Lumantarna R and Ingham JM (2010). "Performance of Unreinforced and Reinforced Masonry Buildings during the 2010 Darfield Earthquake". Bulletin of the New Zealand Society for Earthquake Engineering, 43(4): 321-339. DOI: https://doi.org/10.5459/bnzsee.43.4.321-339
Dizhur D, Ingham JM, Moon L, Griffith M, Schultz A, Senaldi I, Magenes, G, Dickie J, Lissel S, Centeno J, Ventura C, Leite J and Lourenco P (2011). "Performance of Masonry Buildings and Churches in the 22 February 2011 Christchurch Earthquake". Bulletin of the New Zealand Society for Earthquake Engineering, 44(4): 279-296. DOI: https://doi.org/10.5459/bnzsee.44.4.279-296
Cole GL, Dhakal RP and Turner FM (2012). "Building pounding damage observed in the 2011 Christchurch earthquake". Earthquake Engineering and Structural Dynamics, 41(5): 893-913. DOI: https://doi.org/10.1002/eqe.1164
Government of Nepal (2015). “Nepal Earthquake 2015: Disaster Relief and Recovery Information Platform”. Nepal Disaster Risk Reduction Portal, http://drrportal.gov.np (Accessed 24/11/2015).
Ranjitkar RK (2000). “Seismic Strengthening of the Nepalese Pagoda: Progress report. Earthquake-Safe: Lessons to be learned from Traditional Construction”. International Conference on the Seismic Performance of Traditional Buildings, Istanbul, Turkey, Nov. 16– 8, 2000.
Shakya M, Varum H, Vicente R and Costa A (2013). "Seismic sensitivity analysis of the common structural components of Nepalese Pagoda temples". Bulletin of Earthquake Engineering, 12(4): 1679-1703. DOI: https://doi.org/10.1007/s10518-013-9569-6
Parajuli YK, Amatya S and Sturzbecher K (1986). “Experience in preservation and restoration in a mediaeval town (1974-1985)”. Bhaktapur Development Project, Nepal.
Marhatta YB, Bothara JK, Magar MB and Chapagain G (2007). World Housing Encyclopaedia. “Housing Report: Pillar walaghar, URM infilled RC frame buildings”. http://www.world-housing.net/WHEReports/wh100163.pdf. (Accessed 22/11/2015).
Bothara J K and Hiçyılmaz K (2008). “General Observations of the Building Behaviour during the 8th October 2005 Pakistan Earthquake”. Bulletin of the New Zealand Society for Earthquake Engineering, 41(4). DOI: https://doi.org/10.5459/bnzsee.41.4.209-233
Oyarzo-Vera C and Griffith MC (2009). “The Mw 6.3 Abruzzo (Italy) Earthquake of April 6th, 2009: On Site Observations”. Bulletin of the New Zealand Society for Earthquake Engineering, 42(4): 302-306. DOI: https://doi.org/10.5459/bnzsee.42.4.302-307
Bothara J, Beetham R, Brunsdon D, Stannard M, Brown R, Hyland C, Lewis W, Miller S, Sanders R and Sulistio Y (2010). “General Observations of Effects of the 30 September 2009 Padang Earthquake, Indonesia”. Bulletin of the New Zealand Society for Earthquake Engineering, 43(3): p143-173.
Astroza M, Moroni O, Brzev S and Tanner J. (2012). "Seismic Performance of Engineered Masonry Buildings in the 2010 Maule Earthquake". Earthquake Spectra, 28(S1): S385-S406.
Hermanns L, Fraile A, Alarcón E and Álvarez R (2013). "Performance of buildings with masonry infill walls during the 2011 Lorca earthquake". Bulletin of Earthquake Engineering, 12(5): 1977-1997. DOI: https://doi.org/10.1007/s10518-013-9499-3
Copyright (c) 2016 Dmytro Dizhur, Rajesh P. Dhakal, Jitendra Bothara, Jason M. Ingham
This work is licensed under a Creative Commons Attribution 4.0 International License.