# Plastic Deformation and Internal Force Limits for Existing Building

**ICONS**

**b _{w} =** Body width of beam

**d =**useful height of beam and column

**f**

_{ctm }*Tensile strength of existing concrete defined according to*

**=****15.2.4.3**

**L**Plastic hinge length [m]

_{p}=**L**Shear span [m]

_{s }=**V**Column, beam and the design shear force based on the wall

_{e }=**ρ**= the volumetric ratio of the transverse reinforcement in the direction considered

_{sh}**TBDY Article 5.8.1.6 -** Permissible strain and internal force limits in the assessment of existing building elements are defined in **Chapter 15** .

**TBDY Section 15.2.3. Available Material Strength**

The material strengths to be used in calculating the capacities of the carrier elements are defined as the *material strength* available in this section of the Regulation .

**TBDY Section 15.2.12. Knowledge Level Coefficients**

**(a)** The Knowledge Level Coefficients to be applied to the staff capacities according to the knowledge level obtained from the buildings examined are given in **Table 15.1** .

**(b)** Unless specifically stated, material strengths shall not be divided by the material coefficients given in the relevant design regulations. Existing material strengths will be used in the calculation of element capacities.

**TBDY Section 15.7.1. Section Deformation and Plastic Rotation Limits of Reinforced Concrete and Pre-fabricated Reinforced Concrete Elements**

**15.7.1.1 -** Unit deformation demands of concrete and reinforcement steel obtained according to **15.5.4** or **15.6.2** will be compared with the unit deformation capacities defined below, and the performance of the carrier system at the cross-section level will be determined.

**15.7.1.2 - If the** longitudinal reinforcements of the reinforced concrete elements **whose shape** deformation is calculated are arranged with un-ribbed (flat) reinforcing steel, the unit deformation demand of the reinforcing steel and the demand for plastic rotation will be increased by multiplying by 1.5.

**15.7.1.3 -** Permissible unit strain and plastic rotation upper limits (capacities) according to various section damage limits in reinforced concrete ductile beam, curtain and column elements where plastic deformations occur **5.8.1.1** , **5.8.1.2** , **5.8.1.3** and **5.8.1.4** ' well defined. **In the** calculation of ρ _{sh} in **Eq. (5.4d)** , 30% of 90 degree closed stirrups can be taken into account. **In Equation (5.6)** given in **5.8.1.2** , L _{s} shall not be taken less than L _{p} .

**15.7.1.4 - If the** shear force ratio V _{e} / (b _{w} d f _{ctm} ) of the reinforced concrete section for which deformation is calculated is <0.65, the upper limits of deformation calculated according to **15.7.1.3** are valid. If the shear force ratio is greater than 1.30 , the deformation upper limits calculated according to **15.7.1.3** will be reduced by multiplying by 0.50. Linear interpolation will be applied for intermediate values.