Q_acc : Total holizontal equivalent force

a_h : Holizontal acceleration as a function of the fundamental frequency of the structure.
      (see Fig.1 , Fig.2)

g : Acceleration due to gravity

C_k : Construction coefficient

         C_d = Design coefficient (= 0.65)

         K = Deformation coefficient (see Table 1, Table 2)

         G_m = Mean value of the self-weight of the load-bearing structure

: Sum of the accompanying actions occurring simultaneously with the earthquake