Reinforcement Detailing of Beams from ETABS output

CHALLENGE NO -7

Detail design of beams in Etabs 2018.

The ETABS file for a G+4 building is provided. Run the analysis and design the RCC Moment ResistingFrame. The following challenge deals specifically with two continuous beams in the 1st floor.

1) 3 span continuous beam along grid A

2) 7 span continuous beam along grid 3

STEPS-

• Download the model and open in ETABS.
• After opening the model run the analysis.
• After the analysis click on the concrete frame design in the ribbon.
• The checking of model will start.
• After checking we can see the beam detailing values in the plan view.

Finding of maximum vales of Ast from the grids A and grid 3-

FOR GRID 3-

FOR TOP-

• Maximum Ast at support= 1940.
• Maximum Ast at middle = 485.

REINFORCEMENT TO BE PROVIDED-

• 2 Bars of 32mm diameter.
• 1 bar of 25mm diameter.

FOR BOTTOM-

• Maximum Ast at support = 1056.
• Maximum Ast at middle = 1501.

REINFORCEMENT TO BE PROVIDED-

• 3 bars of 25mm diameter.

REINFORCEMENT DETAILS FOR GRID 3-

FOR GRID A-

FOR TOP-

• Maximum Ast at support= 2045
• Maximum Ast at middle= 511

REINFORCEMENT TO BE PROVIDED-

• 2 bars of 32mm diameter.
• 1 bar of 25mm diameter.

FOR BOTTOM-

• Maximum Ast at support= 1945
• Maximum Ast at middle= 789.

REINFOCEMENT TO BE PROVIDED-

• 2 Bars of 32mm diameter.
• 1 bar of 25mm diameter.

REINFORCEMENT DETAILS FOR GRID A-

- Provide reasons for failure of the middle span along grid A. What are the possible ways this issue can be resolved?

FAILURE OF BEAM -

Hogging moment is developed at the mid span of beam. The top reinforcement should be more which has to be extended to the adjoining beams. This is because the side spans are more in length and centre span of beam is less in length.

Hence there is failure of the beam.

• Calculate value of the maximum shear force in any one of the spans in both the continuous beams

• Right click on any of the beam in the grid A or grid 3.
• A new window will be appearing.
• Select details, a result sheet of all details will be appearing.