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.

AIM:

       To run the analysis and design the RCC shear walls shown in the ETABS model.

PROCEDURE:

• Open the given Etabs file.

• The challenge deals specifically with the shear wall of size 300x1500 at grid A-11 in the structural model, so select the shear wall at grid A-11 by selecting all stories.
• Go to plan and select terrace and then select the shear wall at grid A-11.

• Go to elevation view along grid 11.

• Check weather pier assignment done for the shear wall
• Go to set display options select labels and apply.

• Uncheck the pier assignments.

• Run analysis for the model

•  Click on shear wall design

• longitudinal reinforcement for the shear wall.

To check the pier shear reinforcement

• Click on the drop down button near shear wall design in that select display design info and select shear reinforcing and click on apply

• check the pier edge/boundary zones widths

• In the question it is asked for to draw elevation of the shear wall so we have to check the story height
• Go to edit tab click on edit stories and grid systems in that select modify/show story data

   Detailing guideline for shear wall

1. Minimum reinforcement for shrinkage and temperature
2. Ultimate limit state design rebar requirement
3. Ductility rebar requirement

   Whichever is greater should be drawn in RC shear wall detailing

• Classification of shear wall as per IS 13920-2016 clause 10.1.4 - slender wall

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

          = 0.0025 + 0.01375 (300/1500)

• Minimum vertical reinforcement with boundary element as per IS 13920-2016 Table-1 (iii)

             1440 mmsq on left (600mm width boundary element)

             1080 mmsq on right (450mm width boundary element)

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

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

        1/10^th 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

1. 1/3 of minimum member dimension = 300/3 = 100 mm
2. 6 times smallest main rebar = 6 x 25 = 150mm
3. 150mm permissible if vertical bars are spaced at minimum 200mm

      Minimum spacing of confining reinforcement in boundary element is 150 mm

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

Result:

Draw the shear wall along grid A11 using AutoCAD