Challenge

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

IIshant Kanojiya27 Feb 2023

Analysis & Design of RCC shear walls

The tabs file for a G+6 building is provided. Run the analysis and design the RCC shear walls (shown in the tabs 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 the 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 the base up to the terrace.

Aim:- To analyze and design the RCC shear walls using ETABS.

Introduction:- In this project, we will be analyzing and designing a given model using ETABS. Specifically, we will focus on the analysis, design, and reinforcement of shear walls.

The walls we will be working with are our grade 11-A walls. and Extract values of longitudinal steel ratio, boundary element length and shear reinforcing ratio from the design of our results.

Procedure:-

First, open the etabs file and run the analysis
Then go to the shear wall design option

Extract values of longitudinal steel ratio, boundary element length and shear reinforcing ratio from the design results.

Then go to Display info in the shear wall design toolbar
And select option
We get

Designing Values

a.) Flexural Design

Maximum rebar area required - 13,128mm^2

b.) Shear Design Values

Maximum rebar area required - 750 mm^2/m

c.) Boundary Element

Right maximum value - 450mm

Left maximum value - 600mm

Provide cross-sectional steel arrangement of the shear wall from its base up to the 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.

Dimension of the Shear wall - 300 X 1500 mm
Height of walls = 21m

= 1500/300 = 5 > 4 (OK)

= 21000/1500 (mm) = 14 >2 (Slender Wall)

= We use 25mm Dia of Rebar for Longitudinal reinforcement (300/10 = 30mm)

= Take 300mm Maximum spacing of horizontal reinforcement
a) 1/5 X 1500 = 300
b) 3 X 450 =1350
c) 450

Required Longitudinal Reinforcement = 13,128mm^2
So Longitudinal Reinforcement Provide = 28 bars@ 25mm dia = 13,744.4 mm^2

III- Slender walls
=750/(300*1000)=0.0025
= 0.0025+0.5(21000/1500-2)*(0.025-0.025)= 0.0025 (300*1000)=750mm^2 which is same as Etabs Value
= 0.0080*(300*600)=1440mm^2 at left side
=0.0080*(300*450) = 1080mm^2 at right side
= 0.0025*300*1500=1125mm^2
=0.0025+0.01375(300/1500)=2362.5mm^2

Shear reinforcement Required = 750 mm^2/m
Shear Reinforcement Provide = 8mm dia X 8Leg (3 Ring and 2Hooks) = 402.12mm^2/m @ 300mm spacing and as per clause 150mm Spacing for confinement rebar