IS 875:2015 — Clause Reference

Basic Wind Speed Vb

Clause 6.2 provides the basic wind speed (Vb) for India through the wind speed map (Fig. 1). The map divides India into …

Design Wind Speed Vz

Clause 6.3 gives the design wind speed (Vz) at any height z above ground. It is obtained by multiplying the basic wind s…

Risk Coefficient k1

Clause 6.3.1 defines the risk coefficient (k1) which accounts for the desired safety level based on the mean probable de…

Terrain Roughness and Height Factor k2

Clause 6.3.2 defines the terrain roughness and height factor (k2) which accounts for the variation of wind speed with he…

Topography Factor k3

Clause 6.3.3 defines the topography factor k3, which accounts for wind speed acceleration over hills, ridges, cliffs, an…

Importance Factor for Cyclonic Region k4

Clause 6.3.4 introduces the importance factor for cyclonic regions (k4). This factor was newly added in the 2015 revisio…

Wind Directionality Factor Kd

Clause 6.4 introduces the wind directionality factor (Kd), which accounts for the reduced probability that the maximum w…

Design Wind Pressure pz

Clause 7.2 provides the formula for converting design wind speed (Vz) into design wind pressure (pz). The relationship i…

Wind Force on Structure

Clause 7.3 provides the method for calculating the total wind force (F) on a building or structure. The force is compute…

Force Coefficients Cf

Clause 7.4 provides force coefficients (Cf) for calculating wind drag on buildings and structures of various cross-secti…