# Strong Column Condition

**ICONS**

**A _{c} =** Cross-sectional area of the column

**f**Characteristic compressive strength of concrete

_{ck}=**f**Design compressive strength of concrete

_{cd}=**f**Design yield strength of longitudinal reinforcement

_{yd}=**M**Bearing strength calculated according to f

_{ra}=_{cd}and f

_{yd}at the lower end of the free height of the column or wall torque

**M**column or in the upper end of the free height of the curtain for

_{r}=_{CDs}and f

_{yd}'calculated according to the ultimate moment

**M**Moment of positive or negative bearing capacity calculated according to f

_{r}=_{cd}and f

_{yd}on the column or wall face at the left end of the beam

**M**Negative calculated according to f

_{rj}=_{cd}and f

_{yd}on the column or wall face at the right end of the beam j positive bearing strength moment

**N**Axial force calculated under the combined effect of vertical loads and earthquake loads multiplied by the load factors.

_{d}=**V**Sum of shear forces calculated in the direction of the earthquake in all columns on the i'th floor of the building

_{ik}=**V**The sum of shear forces calculated in the direction of the earthquake considered in the columns where (M

_{is}=_{ra}+ M

_{rü}) ≥ 1.2 (M

_{ri}+ M

_{rj}) is provided at both the lower and upper joints of the building.

*At the*ends of the columns

_{meeting the}condition

*N*

_{d}≤ 0.10

*A*

_{c}f

_{ck},

**Eq.**Even if

**(7.3)**is not provided, these columns are also not taken into account in the calculation of

*V*

_{is}.

**7.3.5. The Condition That Columns Are Stronger Than Beams**

**7.3.5.1 - In** load-bearing systems consisting only of frames or a combination of walls and frames, the sum of the load-bearing moments of the columns joining each column-beam node will be at least 20% greater than the sum of the moments of bearing strength in the sections of the column face of the beams connecting to that node ( **Figure. 7.4** ):

**7.3.5.2 - Equation (7.3)** will be applied separately for each earthquake direction and for both sides of the earthquake so as to give unfavorable results ( **Figure 7.4** ). In the calculation of column bearing strength moments, *N *_{d} axial forces which make these moments the smallest in accordance with the direction of the earthquake will be taken into consideration.

**7.3.5.3 -** Special circumstances regarding the application of **Equation (7.3)** are specified in **(a)** , **(b)** and **(c) below** :

**(a) Equation (7.3)** is not compulsory if *N *_{d} ≤ 0.10 *A f* ck in both columns joining the node point .

**(b) It shall** not be checked whether **Equation (7.3) is** fulfilled in single-storey buildings and at joints of multi-storey buildings whose columns do not continue to the upper floor .

**(c) In case the** wall where the beams are stuck works like a column in the weak direction, it will not be checked whether **Equation (7.3) is** fulfilled.

**7.3.6. The Condition Where Columns Are Stronger Than Beams In Some Columns**

**7.3.6.1 -** only carrier in the system consists of combination of or screen and frame by frame, considering the earthquake direction considered building any *i* in the 'th floor, **Eq. (7.4)** ' s in the provision of conditions of the corresponding rigid bottom and / or in some nodes above **Eq. The** failure of **(7.3)** may be allowed.

*At the* ends of the columns _{meeting the} condition *N *_{d} ≤ 0.10 *A *_{c} f _{ck} , **Eq. **Even if **(7.3)** is not provided, these columns can also be taken into account in the calculation of *V *_{is} .

**7.3.6.2 - In the case of Equation (7.4)** , in the interval 0.70 ≤ α _{i} ≤1.0, **Eq. The** bending moments and shear forces acting on the columns where **(7.3) is provided at** both the lower and upper joints shall be increased by multiplying by the ratio (1 **/** α _{i} ). **Equivalent. **Columns that do not meet **(7.3) will** be equipped under the effects of vertical loads and earthquakes occurring in their cross-sections.

**7.3.6.3 - In the** event that **Equation (7.4)** cannot be achieved at any floor , all frames in structural systems consisting of only frames or a combination of walls and frames shall be considered as *frame* with *limited ductility level* according to **Table 4.1** . **As** stated in **7.2.1.3,** it is also possible to use frames with limited ductility level together with walls of high ductility level as mixed systems of ductility level.