Reinforcement Detailing of Beams from ETABS output

aim

Detailed design of concrete buildings -1

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

Address the following issues thereafter.
• Provide details of longitudinal and shear reinforcement for the two continuous beams. Sketch the beam elevation details or draft it using autocad software. A sample of how beam elevation details is prepared in consultancy firms is provided below. Participants can prepare it as per their preference:

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

• Calculate value of the maximum shear force in any one of the spans in both the continuous beams, as per clause 6.3.3 (b) in IS 13920 – 2016. Also, confirm these values from shear force demand calculated by ETABS.Please note that if longitudinal reinforcement provided is more than required

preocedure

• We are going to review the supplied input.
• Input was already developed structural model of a G+4 building.
• So the supplied input was openend using the Etabs applicatio.
• And the model was reviewd.
• And as said the model was set to run the analysis.
• Thus run analysis is shown below
• 
• in plan view select the first floor plan and apply it
• 
• select at grid 3 and click it
• 
• next step and run analyse
• 
• select concrete frame design and click it
• 
• select the display design info
• 
• • And as said in the question we have taken said beams in consideration.
  • The considered beams are shown below

  Longitudinal reinforcement of the beam for Grid A

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• 
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• Longitudinal reinforcement of the beam for Grid 3
• 
• Shear Reinforcement of beam for Grid 3
• 
• shear reinforcement at grid a
• 
• The obtained are the information of said beams.
• After this we are seeing the mid sapn failure of the beam in grid A.
• Here O/S means overstressed
• The stress has increased beyond the allowable value thats why it impossible to calculate here
• 
• 
• 
• 
• Shear stress in load/area, We have to reduce the loading or increase the loading are the available suggestions as asked
• Shear capacity of the concrete, it varies according to the grade of concrete
• Instead of using M25 grade if used higher grade for this beam alone we can make the beam pass in the shear stress.
• • For the calculation of maximum shear force .
  • we are refering IS456-2002 clause 40.4
  • And the formula is

  V_us = (0.87fyA_svd)/S_v mm²

  _Where

  fy = 415N/mm²

  A_sv = 151mm²

  d= 450mm

  S_v = 100mm

• As per the observations from the drawing and IS Code

  And

  V_us = 245KN

• load combination
• 
• next sway connection of shear and beam connection
• 
• sway shear right mbh =234kn
• mas=174kn mbs=155knm
• mbh= 293kn Lab =4.725kn
• Lab=4.725kn ld+1 =70kn
• vua=46kn vuu= 185kn
• vub= 230kn
• sway shear of the diagram
• 
• • Result:
  • The model was inserted.
  • resolution was given.