5. Nepal’s geographic location and wind
exposure
-Its geographic location is between 26°22′N and 30°27′N
latitudes and 80°4′E and 88°12′E longitudes.
-As for wind exposure, Nepal's wind patterns are influenced by
its geographical features and surrounding climate systems
Fig.1 Geographical map of Nepal
Source-en.wikipedia.org
6. IMPORTANCE OF CONSIDERINGWIND
EFFECTS IN BUILDING DESIGN:
• STRUCTURAL STABILITY
• SAFETY OF OCCUPANTS
• COMFORT AND HABITABILITY
• ENVIRONMENTAL IMPACT
• LONG-TERM DURABILITY
• Monsoon season brings heavy rainfall from June to September.
• Himalayas influence wind circulation and cause varying wind intensities.
• Terai region experiences higher wind speeds during the monsoon.
• Valleys may have unique wind patterns and turbulence.
• Seasonal variations in wind direction and intensity.
• Weather systems like cyclones can affect wind intensity.
WIND PATTERN AND INTENSITY
VARIATION:
7. OBJECTIVES
• Analyze Nepal's wind climate for precise design
criteria.
• Ensure structural safety against wind forces in
various infrastructures.
• Promote sustainable, resilient construction practices
in Nepal.
9. WIND LOADS STANDARDS
Codes in Nepal
Indian Standard IS 875 (Part 3): Nepal has historically used
Indian standards for building design, and IS 875 (Part 3)
provides guidelines for the calculation of wind loads on
buildings and structures.
Nepal National Building Code (NBC): The NBC is a
comprehensive document that covers various aspects of
building construction, including structural design. It might
incorporate wind load provisions from recognized
international standards.
American Society of Civil Engineers (ASCE 7): Some
countries outside the United States adopt ASCE 7 as a
reference standard for wind load calculations.
11. A CASE STUDY OF BARA AND PARSA
Bara and Parsa districts affected by the tornado
Meteorological history
• Duration~40 minutes
• Formed March 31 2019 7:45 PM (NPT)
• Dissipated~ March 31 2019 8:15 PM (NPT)
• EF2+ tornado on the Enhanced Fujita scale
• Highest winds180 to 330 km/h (110 to 210
mph)
• Overall effects
• Fatalities28 (official), 50 (reported)
• Damage NRs. 90 million ($800,000 USD)
• Areas affected Bara and Parsa districts of
Nepal
• Houses destroyed 1,059 (1,342 homes
damaged)
Source-
https://upload.wikimedia.org/wikipedia/comm
ons/0/0a/Nepal_Province_No._2_adm_locatio
n_map.svg
12. [Source: Bara-Parsa tornado report]
The photograph displays
the wind direction
showing convergence as
indicated by
the tilting of the trees.
One red arrow indicates
the southward wind
direction, while
another red arrow
indicates the northward
wind direction
simultaneously
14. RESULTS AND DISCUSSION
RESULTS:
• The Bara and Parsa Tornado
occurred in 2019, affecting
these districts in Nepal,
• The tornado had a wind
speed,180 to 330 km/h (110
to 210 mph)
• causing significant damage
to buildings, infrastructure,
and vegetation in the
affected areas.
• 18 Loss of life and MORE
THAN 1,100 injuries were
reported due to the
tornado's impact.
15. RESULTS & DISCUSSION
• Meteorological analysis
indicated that the tornado
was a rare and localized
weather phenomenon in
the region, highlighting
the need for improved
forecasting and early
warning systems in Nepal.
• The tornado's path and
intensity demonstrated
the importance of
implementing wind-
resistant building codes
and infrastructure design
criteria in the affected
districts to reduce future
damages and enhance
community resilience.
DISCUSSIONS:
16. WIND RESISTANCE DESIGN STRATEGIES
• Shape and Aerodynamics
• Orientation
• Reduced Openings
• Reinforced Roofing
• Secure Cladding
• Enhanced Structural System
• Cross-Bracing and Diaphragms
• Impact-Resistant Windows
• Windbreaks
17. • WIND TUNNEL TESTING FOR
TALL AND COMPLEX
STRUCTURE
• USE OF WIND BREAKERS, BARRIER AND
DEFLECTORS
19. CONCLUSION
• analyzing nepal's wind climate is crucial for
establishing precise design criteria to ensure
structural safety against wind forces.
• understanding specific wind patterns, seasonal
variations, and extreme events is essential for
developing effective guidelines for various
infrastructures.
• implementing wind-resistant design principles in
construction practices will mitigate potential hazards
and improve disaster preparedness.
20. RECOMMENDATION
• Strong Foundation: Construct buildings with
reinforced foundations capable of withstanding
high wind forces and potential debris impact.
• Wind-Resistant Materials: Use materials that
can withstand strong winds, such as reinforced
concrete and impact-resistant windows.
• Storm Shelters: Include designated storm
shelters or safe rooms in buildings to provide a
secure place for occupants during tornadoes.
• Roof Design: Implement a roof design that is
aerodynamic and securely anchored to the
building structure.
• Compliance with Local Codes: Ensure that the
building design adheres to local tornado-resistant
building codes and standards.
