Analysis & Design of RCC shear walls in the model using ETABS

The etabs file for a G+6 building is provided. Run the analysis and design the RCC shear walls (show in the etabs model). The following challenge deals specifically with the shear wall of size 300x1500 at grid A-11 in the structural model.

• Extract values of longitudinal steel ratio, boundary element length and shear reinforcing ratio from the design results.
• Provide cross sectional steel arrangement of the shear wall from its base up to terrace, in compliance with provisions of IS 13920 – 2016. AutoCAD application can be used for this exercise. Alternatively, it can be drawn by hand as well.
• Provide elevation drawings of the reinforcement details of the shear wall from base up to terrace.

ANS:

• Open Challenge and download the attached file
• open it in the etabs.
• run the model.

• go to the plan tab<Terrace<ok

• select grid A11 <ok
• go to elevation tab<select 11<ok

• Next we have to start the designing of shear wall
• click on shear wall design < 'Start Design/Check

Detail for shear wall:

1. Minimum reinforcement for shrinkage & temperature
2. Ultimate limit state design rebar requirement - Whichever is greater should be drawn in RC shear wall detailing
3. Ductility rebar requirment

• Classification of shear wall as per IS13920- 2016clause 10.1.4 Slender wall hw/lw

= 21000/1500=14>2

• Minimum net vertical reinforcement as per IS 13920-2016 Table 1(iii)2363mm2

=0.0025+0.01375(300/1500)

• Minimum vertical reinforcement within boundary element Table 1(iii)

1440mm2 on left (600mm width boundary element

1080mm2 on right (450mm width boundary element

• Mnimum horizontal reinforcement in shear wall as per IS -13920 - 2016 table 1(iii)

Ph=750/(300x1000)=0.0025,hw=21000,Lw=1500

(ph)min=0.002+0.5(21/15-2)x0

(ph)min=0.0025 which is the same 750mm2/m

• Maximum diameter of rebar of shear wall as per IS 13920-2016 clause 10.1.8

1/10th of wall thickness = 300/10=30mm

Commercial rebar diameter 25mm shall be adopted

• Confining reinforcement spacing for boundary element as per IS 13920-2016 clause 10.4.4

(i)1/3 of minimum member dimension 300/3=100mm

(ii)6 times smallest main rebar =6x25=150mm

(iii)150mm permissible if vertcal bars are spaced at maximum 200mm

Maximum spacing of confining reinforcement in boundary element 150mm

• Confining reinforcement within boundary element as per IS 13920-2016 clause 10.4.4

Sv=150mm,h=1000mm

Ash=452mm2