Reinforcement Detailing of Beams from ETABS output
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
Q)
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:
ans) given figure is analysed using check model and analysis is run.
after that we get the different values for area of steel at each beam as shown below.
bars calculation is done along grid A and 3.
calculated number of bars is represented in autocad interface as shown in figure.
Q)
Provide reasons for failure of the middle span along grid A. What are the possible ways this issue can be resolved?
ans)along the grid A there is non uniformity of span because of which the load distribution is disturbed. in order to resole it
the all the spans should be equal sized. hence due to unequal length of middle span compared to other two leads to failure.
Q)
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 (as per ETABS results), the shear force demand will vary from what is provided by ETABS.
ans) after the model is checked and analysis is done, we get the values of steel at each beam.
right click on anyone of the beam and we get the table of details containing load combinations top steel and bottom steel.
after clicking on details we get the values for design force and factored design force.
if the design force is greater than factored force,then analysis is correct.
