VERTICAL DISTRIBUTION OF BASE SHEAR

After identifying the base shear, which is the force to move the whole structure from the ground, the next step is to distribute the base shear among the number of floors of the structure. The formula used is as follows:

         
                                 

where: Ft = the portion of the base shear, V, considered concentrated at the top of the structure in addition to Fn.
                                

                                
                                    where:  T  = elastic fundamental period
                                                  V = design base shear

NOTE:
1. Ft need not exceed 0.25 V.
2. Ft = 0 when T <=0.70 seconds

The lateral force per floor will then be computed as:                     
                                          
                                  

Floor	weight	cummulative height	wt*ht	Cvx	V per floor
1
2
3

WEIGHT = the weight (kN) per floor of the structure

CUMMULATIVE HEIGHT = Height of the floor from the ground or base
Cvx        = % distribution of weight x height
                            

                                
V per floor = base shear distribution of each floor