seismic base shear value in SRSS output file are not matching

Dear sir,

I am doing the dynamic analysis by SRSS method of the rack structure .

I had observered that the total reaction given by staad in X,Y and Z is not matching with the base shear shown in output file.

Idealy it should match since we want to design our structure by SRSS methord and so we are scaling up by factor to match the same.

for given example

base shear by srss = 31.73 kN in x direction (load case 9) but staad is giving total reaction in load case 9 = 29.627 kN

base shear by srss = 12.41 kN in y direction  (load case 10) but staad is giving total reaction in load case 9 = 17 kNcommunities.bentley.com/.../rack.std

base shear by srss = 25 kN in x direction (load case 11)  but staad is giving total reaction in load case 9 = 41 kN

now if you observe there is vast difference in result in Y and Z direction load case.

for reference I am attaching staad file.

Please guide me.