Code Name  IS 1893(Part 1):2002 ( Criteria for Earthquake Resistant Design of structures ) 

Issued by  Bureau of Indian Standard  
Revision  Fifth Revision  
Horizontal Base Shear  Where,


Design horizontal Seismic coefficient  Where,


Fundamental natural period (T_{a})  For moment resisting frames without brick infill
panels may be estimated as below, T_{a }= 0.075 h ^{0.75} for R. C. Framed building = 0.085 h ^{0.75} for Steel Framed building where, h is height of the building in m. For others building may be estimated as below, @T_{a} = 0.09 /(d) Where, d (in m) is base dimension of building at plinth level along the considered direction of the lateral forces. 