Beamless Flooring - Reason for choosing R Report table

[obguner]

Hello, I have a project of a beamless flooring system. I share with you a confusing point asked by the control engineer. According to this table in the reason for choosing the R coefficient of the report, it seems that Mdev>0.75 of the 4.3.4.6 article of the earthquake code should be provided for A12 and A13 selected for beamless floors. It is written in the 4.3.4.6 regulation that it must be met only in mixed systems. idestatic makes a 2-stage solution in beamless slab systems. But this part of the report is confusing. I couldn't find any explanation about this that I can share with the control engineer. Waiting for your opinions and ideas. I wish you a good day.

 

[Levent Özpak]

Re: Beamless Flooring - R Selection Reason About Report Table Hello, R Coefficient Chart and the statement in Article 4.3.4.6, if the condition in Equation 4.2 is not met, the ductility level of all the earthquake effects of the structural system type is high. It is related that the R, D coefficients defined for the cases met with curtains and the maximum allowed BMS should be taken into account. In non-beam tiled systems, on the other hand, in Article 4.3.4.4, two-stage calculations are required, and in the 1st stage calculation, all earthquake loads must be met by the shear walls. There is no sanction for providing the total Mdev>=0.75Mo condition.

 

[sahinsukru]

Re: Beamless Flooring - Reason for choosing R About Report table

hello, I have a beamless flooring system project. I share with you a confusing point asked by the control engineer. According to this table in the reason for choosing the R coefficient of the report, it seems that 4.3.4.6 of the earthquake code Mdev>0.75 should be met for A12 and A13 selected for beamless floors. However, this part of the report is confusing. I couldn't find any explanation that I can share with the control engineer about it. I am waiting for your opinions and ideas. I wish you a good day.

shears with bond beams (with gaps) and/or without gaps or with a gap with limited ductility level z will be covered by the curtains. According to this article, Mdev>0.75 must be provided. Therefore, there is no problem with the display in my opinion. In other words, A12 or A13 (when this condition is met, non-beam slabs can also be used in buildings with BYS>=2).

 

[obguner]

Re: Beamless Flooring - Reason for choosing R About the report table

Hi, there is no sanction for meeting the condition of Total Mdev>=0.75Mo

You are right Levent Sir, but the statement that it must be greater than 0.75 creates confusion. In the 2-stage solution, when we solve the joints of the columns in the 1st stage, the walls will carry all the moment, not 0.75, that is. It would be useful to give the + sums they carry or the + sums of the total earthquake load carried by the walls in framed systems, and to what extent the shears carry all the earthquake moment.