7.6.7 Example
Sample
The design shear force values of the P04 curtain arm belonging to the wall group named GP1 of the 8-storey building, whose plan image is given below and each floor height is 3m, will be calculated under the combination of G '+ Q'-Ey-0.3Ex + 0.3Ez loading. Since the structure is a curtain frame system with high ductility level in the X direction, it is considered as R = 8 and D = 2.5 in this direction, and R = 7 and D = 2.5 because it is a shear frame system with high ductility level in the Y direction.
For GP1 group curtain, H w = 3 × 8 = 24m. Since l w = 4.25m, H w / l w = 24 / 4.25 = 5.65> 2.0. In this case , the design shear force values for the sections of the GP1 group wall in the lower region of the height H w / 3 are as follows.
The values of shear force, V2, and bending moment, M3, affecting the base of the GP1 group wall due to vertical loads and earthquake effects are given in the table below. Here, Ex and Ey values are written taking into account the additional eccentricity effect and Equivalent Base Shear Force Amplification Coefficient .
Internal forces occurring at the GP1 group curtain base | G' | Q' | Ex | Oh | Ez (G) |
|---|---|---|---|---|---|
Shear Force (V2) | 1.013 tf | 0.229 tf | 26.633 tf | 41.930 tf | 0.445 tf |
Bending Moment (M3) | 66.383 tfm | 17.210 tfm | 211.389 tfm | 361.138 tfm | 29.173 tfm |
The values of V d and (M d ) t shown in TBDY Equation 7.16 are the shear force and bending moment values calculated under the combined effect of vertical loads and earthquake loads, respectively, multiplied by the load coefficients. In this case , V d and (M d ) t for the loading combination G '+ Q'-O-0.3Ex + 0.3Ez ; V d = (-1.013) + (-0.229) - (41.930) - 0.3 × (26.663) + 0.3 × (-0.445) = -51.295 tf (M d ) t = (66.383) + (17.210) - (361.138) - 0.3 × (211.389) + 0.3 × (29.173) = -333.63 tfm .
Dynamic magnification coefficient is taken as β v = 1.5 because it is a gapless screen in Y direction . As a result of the moment curvature analysis performed by taking into account the axial force and biaxial bending under the G '+ Q'-Ey-0.3Ex + 0.3Ez loading combination , the bearing strength moment (M p ) found in the base section of the GP1 group wall by using the material strengths f ck and f yk t = 2030.66 tfm. In this case , V e 'value found by Equation 7.16 ;
was found as. It is obtained by increasing the shear force value V e ' found by Equation 7.16 according to TBDY Article 7.6.6.3 by the factor of 1.2D (solid walls) of the shear forces calculated from the earthquake under the combination of G' + Q'-Ey-0.3Ex + 0.3Ez loading. The shear force value, V e , should be compared. Shear force value smaller than V e and V e 'value will be used as design shear force value. In this case , the shear force value obtained by 1.2D magnification of the earthquake loads under the combination of G '+ Q'-Ey-0.3Ex + 0.3Ez loading, V
e = (1.013) + (-0.229) - (1.2 × 2.5 × 41.930) 0.3 × (1.2 × 2.5 × 26.663) + 0.3 × (-0.445) = -151.63 tf
.
Since V e = -151.63 tf and V e '= 469.83 tf, the design shear force used in the transverse reinforcement calculation for the P04 branch base ofthe GP1 wallis considered as V e = -151.63 tf. While the design shear force values are found for the sections in the upper region of the height H w / 3 of the GP1 group curtain, in addition to the above operations, TBDY Figure 7.12c
The linearized design shear force diagram specified in.
In Figure 1a , the shear force, V d , under the combined effect of vertical loads and earthquake loads under the combination of G '+ Q'-O-0.3Ex + 0.3Ez is shown with green lines.
Figure 1b from G + Q'-O-0.3ex + 0.3ez vertical loads under the loading combination and earthquake 1.2D shear force resulting from amplification with the solid load V e and Equation 7.16 The shear force obtained with the V e ' The shear force diagram obtained by comparing the values is shown with blue lines. ( TBDY Article 7.6.6.3 )
The Design Shear Force diagram is shown in Figure 1c . In this shear diagram, the lower part of the height H w / 3 has the same values as the shear diagram shown in Figure 1b. In the upper part of the height H w / 3 , the linearized shear force diagram mentioned in TBDY Figure 7.12c is shown with red lines. In this shear diagram, V d (green) and V e (blue) values are also shown.
For the P03 and P05 arms of the GP1 group curtain, the same procedure is applied. The above procedures are applied under each loading combination for all branches of the group walls, and the most unfavorable situation is used in transverse reinforcement design. The conformity of the selected transverse reinforcement is checked by comparing the shear strength of the shear wall found in accordance with Article 7.6.7 of TBDY and the results.
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