Architecture & Structural Engineering

Story Drifts Control Example Calculation

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Let's determine the story drifts obtained in the seismic loading of a 3-stories building with a system consisting of a reinforced concrete moment transfer frame with a span of 2 * 4 m in the Y direction and a span of 2 * 6 + 8 m in the X direction, and let's compare it with the limit value.

Solution:

First, it is necessary to determine the column with the highest horizontal displacement in EX loading on each floor. For this, perspective screen-view analysis model - deformations - EX loading is selected. The X-direction displacement of the top joint of the columns at each level is read.

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To determine the relative translation, it is necessary to read the displacements that will give the greatest difference. The readings made on the other floors are as follows:

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The values ​​read are the raw values ​​as a result of the analysis. It should be increased in accordance with TBDY 2018 4.8.4 according to the equivalent base shear force enlargement coefficient.

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The equivalent base shear force amplification coefficient given for the X direction in the dynamic analysis report was determined as 1.22. The raw values ​​read on the perspective screen need to be incremented by 1.22. According to this;

(9.64*1.22)-(6.22*1.22)=4.17

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