Shearwall Overturning Control
Since the building is DTS = 1 and all seismic loads are covered by reinforced concrete walls, it is necessary to control the shearwall overturning in both directions. This control is the stage that allows the final decision to be made on the R coefficient. If the conditions given below are not met, (4/5)R must be used instead of the selected R. These two conditions are as follows:
(a) The base overturning moment MDEV taken by a single shear wall or steel braced frame in the structural system shall not be more than 1/3 of the total base overturning moment Mo resulting from seismic loads for the whole building in that direction.
(b) The sum of the base overturning moment MDEV or MDEV's taken by the shearwalls or steel braced frames on each side axis of the building shall not be less than 1/6 of the total base overturning moment Mo resulting from the seismic loads for the whole building in that direction. .
This control is done automatically by taking R = 1 by the program.
Since it is necessary to make an analysis to see the results of this control, it is necessary to do an analysis after selecting R and D and pay attention to the warnings in the control of shearwall overturning moment section in the earthquake code general report.
In the report visuals given above for the X direction, it is seen that (4/5) R is taken instead of R for the X direction, since item (a) does not provide. The same is true for the Y direction.
As a result of the controls in the building, it is necessary to use (4/5) R in both directions, so the relevant boxes next to the R coefficients in the analysis settings should be marked and re-analyzed. Post marking program (4/5) uses R in accounts and reports that the transaction is correct by showing that it is used in overturning reports.
