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

CHALLENGE 9:

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

AIM:

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

INTRODUCTION:

ETABS software was used to model and design the shear walls for the building. The following steps were taken to model and design the shear walls:

1. A model of the building was created in ETABS software.

2. The model was analyzed for seismic loads.

3. The shear walls were designed to resist seismic loads.

4. The model was checked for compliance with the building code.

The analysis results showed that the shear walls could resist the seismic loads and comply with the building code.

QUESTION:

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.

PROCEDURE:

1. Open the existing Etabs model.

2. Now we have to design a particular shear wall crossing Grids A and 11 and going the view the Terrace.

3. Now select the entire all stories shear wall Grid A and 11 and simply click right-click to select the show objects.

4. Now go to the view elevations along Grid 11.

5. After that check whether the piers are done for shear walls or not. Go to the view options to select the labels.

6. Piers are done in the above model after that to uncheck the labels.

7. Now run the analysis.

8. Now click the Shear wall design option.

9. After that dropdown the shear wall design to select the design info to change the pier shear reinforcing, Boundary Zone widths , and Horizontal Reinforcing and click apply.

10. Now note down the elevations of the model.

Detailing Guideline for Shear walls:

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

Above three points 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 =21000/1500= 14>2
• Minimum net vertical reinforcement as per IS-13920-2016 Table-1 (iii)

2363 mm2=0.0025 +0.01375 (300/1500)

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

1440 mm2 on left (600mm width boundary element)

1080 mm2 on right (450mm width boundary element)

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

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

(Ph)min = 0.0025 + 0.5 (21/15 - 2) x0

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

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

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

Commercial rebar diameter of 25mm shall be adopted

• Confining reinforcement spacing for boundary elements as per IS-13920-2016 clause 10.4.4
  (i) 1/3 of minimum member dimension = 300/3 =100 mm

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

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

maximum spacing of confining reinforcement in boundary element 150 mm

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

Sv=150 mm, h = 1000 mm

Ash = 452 mm2

AutoCAD Drawings:

RESULTS:

1. Analysis was performed and RCC Shear Wall was designed.
2. Extract values of longitudinal steel ratio, boundary element length, and shear reinforcing ratio from the design results.
3. 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

CHALLENGE 9:

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

AIM:

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

INTRODUCTION:

ETABS software was used to model and design the shear walls for the building. The following steps were taken to model and design the shear walls:

1. A model of the building was created in ETABS software.
2. The model was analyzed for seismic loads.
3. The shear walls were designed to resist seismic loads.
4. The model was checked for compliance with the building code.

The analysis results showed that the shear walls could resist the seismic loads and comply with the building code.

QUESTION:

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.

PROCEDURE:

1. Open the existing Etabs model.
2. Now we have to design a particular shear wall crossing Grids A and 11 and going the view the Terrace.
3. Now select the entire all stories shear wall Grid A and 11 and simply click right-click to select the show objects.

4. Now go to the view elevations along Grid 11.
5. After that check whether the piers are done for shear walls or not. Go to the view options to select the labels.
6. Piers are done in the above model after that to uncheck the labels.
7. Now run the analysis.
8. Now click the Shear wall design option.
9. After that dropdown the shear wall design to select the design info to change the pier shear reinforcing, Boundary Zone widths, and Horizontal Reinforcing and click apply.

10. Now note down the elevations of the model.

Detailing Guideline for Shear walls:

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

Above three points 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 =21000/1500= 14>2
• Minimum net vertical reinforcement as per IS-13920-2016 Table-1 (iii)

2363 mm2=0.0025 +0.01375 (300/1500)

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

1440 mm2 on left (600mm width boundary element)

1080 mm2 on right (450mm width boundary element)

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

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

(Ph)min = 0.0025 + 0.5 (21/15 - 2) x0

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

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

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

Commercial rebar diameter of 25mm shall be adopted

• Confining reinforcement spacing for boundary elements as per IS-13920-2016 clause 10.4.4
  (i) 1/3 of minimum member dimension = 300/3 =100 mm

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

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

maximum spacing of confining reinforcement in boundary element 150 mm

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

Sv=150 mm, h = 1000 mm

Ash = 452 mm2

AutoCAD Drawings:

RESULTS:

1. Analysis was performed and RCC Shear Wall was designed.
2. Extract values of longitudinal steel ratio, boundary element length, and shear reinforcing ratio from the design results.
3. 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