η bi = Torsional Irregularity Coefficient defined on the i th floor

5.6.2. Single Mode Pushover Analysis Methods – Single Mode Pushover Analysis Methods is the nonlinear incremental counterpart of the single mode implementation of the linear Mode Combination Method described in Chapter 4 . – In order for the Single Mode Pushover Analysis Methods to be applicable , both the conditions given in (a) and (b) below must be met:

(a) The torsional irregularity coefficient calculated according to Table 3.5 of Chapter 3 , based on linear elastic behavior without considering additional eccentricity in any storey , must satisfy the condition ηbi <1.4.

(b) The ratio of the effective mass of the base shear force of the first (dominant) vibration mode calculated on the basis of the linear elastic behavior in the earthquake direction considered, to the total building mass (excluding the masses of the basement floors surrounded by rigid shears ) must be at least 0.70. - Single Mode Pushover Analysis Methods ' in, under the influence Taking into consideration the earthquake direction dominant vibration mode shape earthquake displacement so as to be proportional to the demand limits until monotonic in step applied seismic load increment in the carrier system consisting substituent , plastic deformation (plastic rotation , elongation, etc.) and internal force increments and their cumulative values ​​are calculated. In the last step, the cumulative values ​​corresponding to the earthquake demand are obtained as the base quantities for deformation evaluation . – In this Section, Single Mode Pushover Analysis Methods are explained for the case where the assumption of a rigid diaphragm is made for the floors at each floor and the degrees of freedom are defined as the horizontal displacement components in two perpendicular directions at the storey mass center and the rotation around the vertical axis. In case the degrees of freedom corresponding to in-plane deformations in floor slabs are taken into consideration, single-mode pushing methods can be adapted within the same principles.

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