scholarly journals Unearthed lessons of 25 April 2015 Gorkha earthquake (MW 7.8): geotechnical earthquake engineering perspectives

2017 ◽  
Vol 8 (2) ◽  
pp. 1358-1382 ◽  
Author(s):  
Dipendra Gautam
Keyword(s):  
Earthquake Engineering ◽  
Gorkha Earthquake ◽  
Geotechnical Earthquake Engineering ◽  
2015 Gorkha Earthquake

Implementing Nepal's National Building Code: A Case Study in Patience and Persistence

2017 ◽  
Vol 33 (1_suppl) ◽  
pp. 167-183 ◽  
Author(s):  
Lucy Arendt ◽  
Ayse Hortacsu ◽  
Kishor Jaiswal ◽  
John Bevington ◽  
Surya Shrestha ◽  
...  
Keyword(s):  
Earthquake Engineering ◽  
Relative Effectiveness ◽  
Building Code ◽  
National Society ◽  
Gorkha Earthquake ◽  
Engineering Research ◽  
2015 Gorkha Earthquake ◽  
Code Compliance ◽  
And Training

The April 2015 Gorkha earthquake in Nepal revealed the relative effectiveness of the Nepal Standard or the national building code (NBC), and irregular compliance with it in different parts of Nepal. Much of the damage to more than half a million residential structures in Nepal may be attributed to the prevalence of owner-built or owner-supervised construction and the lack of owner and builder responsiveness to seismic risk and training in the appropriate means of complying with the NBC. To explain these circumstances, we review the protracted implementation of the NBC and the role played by one organization, the National Society for Earthquake Technology—Nepal (NSET), in the implementation of the NBC. We also share observations on building code compliance made by individuals in Nepal participating in workshops led by the Earthquake Engineering Research Institute's 2014 class of Housner Fellows.

scholarly journals The Influence of Surface Topography on the Weak Ground Shaking in Kathmandu Valley during the 2015 Gorkha Earthquake, Nepal

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 678
Author(s):  
Mark van der Meijde ◽  
Md Ashrafuzzaman ◽  
Norman Kerle ◽  
Saad Khan ◽  
Harald van der Werff
Keyword(s):  
Numerical Simulations ◽  
Surface Topography ◽  
Seismic Energy ◽  
Spectral Element ◽  
Kathmandu Valley ◽  
Ground Displacement ◽  
Gorkha Earthquake ◽  
Ground Shaking ◽  
Earthquake Scenarios ◽  
2015 Gorkha Earthquake

It remains elusive why there was only weak and limited ground shaking in Kathmandu valley during the 25 April 2015 Mw 7.8 Gorkha, Nepal, earthquake. Our spectral element numerical simulations show that, during this earthquake, surface topography restricted the propagation of seismic energy into the valley. The mountains diverted the incoming seismic wave mostly to the eastern and western margins of the valley. As a result, we find de-amplification of peak ground displacement in most of the valley interior. Modeling of alternative earthquake scenarios of the same magnitude occurring at different locations shows that these will affect the Kathmandu valley much more strongly, up to 2–3 times more, than the 2015 Gorkha earthquake did. This indicates that surface topography contributed to the reduced seismic shaking for this specific earthquake and lessened the earthquake impact within the valley.

Characterizing the Kathmandu Valley sediment response through strong motion recordings of the 2015 Gorkha earthquake sequence

2017 ◽  
Vol 714-715 ◽  
pp. 146-157 ◽  
Author(s):  
S. Rajaure ◽  
D. Asimaki ◽  
E.M. Thompson ◽  
S. Hough ◽  
S. Martin ◽  
...  
Keyword(s):  
Strong Motion ◽  
Earthquake Sequence ◽  
Kathmandu Valley ◽  
Gorkha Earthquake ◽  
2015 Gorkha Earthquake

scholarly journals Comparison of Earthquake-Triggered Landslide Inventories: A Case Study of the 2015 Gorkha Earthquake, Nepal

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 437 ◽  
Author(s):  
Meena ◽  
Tavakkoli Piralilou
Keyword(s):  
Risk Mitigation ◽  
Landslide Susceptibility Mapping ◽  
Gorkha Earthquake ◽  
Area Distribution ◽  
2015 Gorkha Earthquake ◽  
The World ◽  
Mapping Techniques ◽  
Event Based ◽  
The Impact

Despite landslide inventories being compiled throughout the world every year at different scales, limited efforts have been made to critically compare them using various techniques or by different investigators. Event-based landslide inventories indicate the location, distribution, and detected boundaries of landslides caused by a single event, such as an earthquake or a rainstorm. Event-based landslide inventories are essential for landslide susceptibility mapping, hazard modeling, and further management of risk mitigation. In Nepal, there were several attempts to map landslides in detail after the Gorkha earthquake. Particularly after the main event on 25 April 2015, researchers around the world mapped the landslides induced by this earthquake. In this research, we compared four of these published inventories qualitatively and quantitatively using different techniques. Two principal methodologies, namely the cartographical degree of matching and frequency area distribution (FAD), were optimized and applied to evaluate inventory maps. We also showed the impact of using satellite imagery with different spatial resolutions on the landslide inventory generation by analyzing matches and mismatches between the inventories. The results of our work give an overview of the impact of methodology selection and outline the limitations and advantages of different remote sensing and mapping techniques for landslide inventorying.

scholarly journals Influence of Structure on the Aseismic Stability and Dynamic Responses of Liquefiable Soil

2021 ◽  
Author(s):  
Pengfei Dou ◽  
Chengshun Xu ◽  
Xiuli Du ◽  
Su Chen
Keyword(s):  
Earthquake Engineering ◽  
Damping Ratio ◽  
Free Field ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Seismic Stability ◽  
Geotechnical Earthquake Engineering ◽  
Liquefiable Soil ◽  
Porewater Pressure ◽  
Lateral Displacements

Abstract In previous major earthquakes, the damage and collapse of structures located in liquefied field which caused by site failure a common occurrence, and the problem of evaluation and disscusion on site liquefaction and the seismic stability is still a key topic in geotechnical earthquake engineering. To study the influence of the presence of structure on the seismic stability of liquefiable sites, a series of shaking table tests on liquefiable free field and non-free field with the same soil sample was carried out. It can be summarized from experimental results as following. The natural frequency of non-free field is larger and the damping ratio is smaller than that of free field. For the weak seismic loading condition, the dynamic response of sites show similar rules and trend. For the strong ground motion condition, soils in both experiments all liquefied obviously and the depth of liquefaction soil in the free field is significantly greater than that in the non-free field, besides, porewater pressure in the non-free field accumulated relately slow and the dissapited quikly from analysis of porewater pressure ratios(PPRs) in both experiments. The amplitudes of lateral displacements and acceleration of soil in the non-free field is obviously smaller than that in the free field caused by the effect of presence of the structure. In a word, the presence of structures will lead to the increase of site stiffness, site more difficult to liquefy, and the seismic stability of the non-free site is higher than that of the free site due to soil-structure interaction.

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