Coupling Beam and Coupled Shearwall Modelling

4.5.4.1 - Reinforced concrete bond beam (hollow) walls are vertical structural system elements in which two hollow curtain parts are connected with tie beams with short and very high shear strengths and work together as a single curtain . Thanks to strong tie beams, these types of curtains show a behavior between curtains without gaps and frames (See 4.5.4.5 ). 

4.5.4.2 - The cross-sectional shapes of the curtain parts forming the tie- beam curtain can be rectangular or generally U or C-shaped like building cores ( Figure 4.1 ).

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4.5.4.3 - The base tipping moment of the bond beam (hollow) wall is calculated by Equation (4.13) :

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Here, the total tipping moment at the base of the wall with M _DEV bond beam (hollow), the bending moments obtained at the base due to the earthquake effect in the curtain parts forming the wall with M ₁ and M ₂ bond beams, and N _V as the sum of the shear forces in the bond beams under the earthquake effect, It corresponds to equal tensile and pressure axial forces formed at the base of the curtain parts. c shows the distance between the cross-section gravity centers of the curtain parts ( Figure 4.1 ). The magnitude obtained from Equation (4.13) is 4.3.4.5 andIn 4.3.4.6 , the curtain base overturning moment will be used as M _DEV .

4.5.4.4 - The bond degree coefficient _Ω , which is taken as basis in the definition of bond beam (hollow) walls, is given in Equation (4.14) .

4.5.4.5 - Bond beam (hollow) screen , Eq. (4.14) 'in the bond order coefficient ' s in Eq. (4.15) 't provides condition according to defined as the structural element:

If the condition defined in Equation (4.15) is not fulfilled, each part of the curtain is deemed to be a curtain without gap . In addition to this condition, in order to prevent the occurrence of excessive axial forces in the curtain parts, the condition ≤ 2 3 / should be tried to be fulfilled.

4.5.4.6 - The curtain parts forming the reinforced concrete tie-beam curtain shall be modeled according to 4.5.3.7 or 4.5.3.8 .  

4.5.4.7 - Tie beams can be modeled as frame members. The effective section stiffness of tie beams will be determined according to 4.5.8 .