Following popular requests, in Tekla Structural Designer 2020 the Wind Wizard for the Indian Head Code has been fully revised and updated to the new IS 875 (Part 3) : 2015 (incorporating amdt. no.1 April, 2016).
The new 2015 code year option is selected in the Design Codes > Action Codes settings as shown in the picture above.
With this selected the Wind Wizard determined pressures are calculated considering all the relevant and newly introduced design factors of the 2015 code version.
The update allows cyclonic design effects to be considered for structures situated on the Indian east and west coasts (Gujarat coastal region).
Key aspects of the Wind code update are:
Classification of building class (A, B and C) based on structure’s greatest horizontal or vertical dimension (exposed to wind) as per Cl.126.96.36.199 (of IS 875 (Part 3) - 1987 (reaff.2003) has been omitted in the new code.
A new importance factor for cyclonic region k4 (Clause 6.3.4) is introduced for the wind pressure determination.
For the design wind pressure determination the following new factors are introduced:
Kd - wind directionality factor (Clause 7.2.1)
Ka - area averaging factor (Clause 7.2.2)
Kc - combination factor (Clause 188.8.131.52)
Design wind speed is now (Vz) = Vb x k1 x k2 x k3 x k4; wind pressure pz = 0.6 x Vz2 and design wind pressure (Pd) = Kd x Ka x Kc x pz
Certain values in the table for pressure coefficient, figures for factors associated with cliff and escarpment and ridge and hill topography have been updated.