ALL CITIES
Seismic zone and basic wind speed of Gangtok
Gangtok, Sikkim. Read off the published IS code zone maps by the CivilSpace Hazard Map.
SEISMIC ZONE
IV
Zone factor Z = 0.24
IS 1893 (Part 1):2016, Fig. 1 and Table 3
BASIC WIND SPEED
47 m/s
Vb, the code value for this city
IS 875 (Part 3), Annex A (Amd. 2 : 2020)
Check with the map in the IS code. Every figure here is read off the published zone maps — IS 1893 (Part 1) Fig. 1 for the seismic zone, and the basic wind speed map for Vb — whose printed boundaries are a line about 3.1 km wide on the ground. Confirm the zone against the code before you design to it.
Common questions
What is the seismic zone of Gangtok?
Gangtok is in seismic zone IV on the IS 1893 (Part 1):2016 zone map, with a zone factor Z of 0.24 (IS 1893 Table 3).
What is the basic wind speed of Gangtok?
The basic wind speed Vb for Gangtok is 47 m/s, the value IS 875 (Part 3) Annex A gives for the city (as amended, Amd. 2 : 2020).