Leaning column base shear

[vahidbarzegar]

I've been analyzing a frame wall 2D building. push over analysis yields a significant base shear (1133 kN) in leaning column base, although the moment of inertia of leaning column is changing to zero in alternate floors. The leaning column script is shown below:

element elasticBeamColumn 5011 301 302 10 200000000.0 0.0 1
element elasticBeamColumn 5021 302 303 10 200000000.0 100.0 1
element elasticBeamColumn 5031 303 304 10 200000000.0 0.0 1
element elasticBeamColumn 5041 304 305 10 200000000.0 100.0 1
element elasticBeamColumn 5051 305 306 10 200000000.0 0.0 1
element elasticBeamColumn 5061 306 307 10 200000000.0 100.0 1
element elasticBeamColumn 5071 307 308 10 200000000.0 0.0 1
element elasticBeamColumn 5081 308 309 10 200000000.0 100.0 1
element elasticBeamColumn 5091 309 3010 10 200000000.0 0.0 1
element elasticBeamColumn 50101 3010 3011 10 200000000.0 100.0 1
element elasticBeamColumn 50111 3011 3012 10 200000000.0 0.0 1
element elasticBeamColumn 50121 3012 3013 10 200000000.0 100.0 1

upper stories of leaning column don't bear any shears.

[fmk]

the base shear you can hand calculate and verify .. it's just: P*delta/L

[vahidbarzegar]

Why shear of upper stories are zero and only the base carries shear?

[fmk]

if you have done it right it is PD/L for each floor .. of course when you look at equi at a node the loads from top column and bottom column the may balance out .. any resulting lateral force at the upper levels are being taken by the frame (it's the purpose of the PD column) so unbalanced from the PD loading is going to the frame (either through some truss or the rigid floor constraint)

[vahidbarzegar]

So should I add this load to base shear- top displacement diagram of the building?

[fmk]

if you want say total base shear you would need to add the loads .. look at horizontal equilibrium of forces to answer your on problem/