Reinforcement Detailing of Beams from ETABS output

Aim:-

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

• Calculate the 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 the 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.

Details:-

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 on the 1st floor.

1) 3-span continuous beam along grid A
2) 7-span continuous beam along grid 3

Address the following issues after that.
• Provide details of longitudinal and shear reinforcement for the two continuous beams. Sketch the beam elevation details or draft it using AutoCAD software. Below is a sample of how beam elevation details are prepared in consultancy firms. Participants can prepare it as per their preference:

Introduction of Beam:-

1. Beams are horizontal structural elements used for supporting lateral loads.
2. In conventional reinforced concrete structures, beams usually receive a load from the floor slab, but may also be subjected to other loads such as wall loads, finishes, services installation, etc.
3. The design and detailing of RC beams involve the selection of the proper beam size and the quantity of longitudinal and shear reinforcement that will satisfy ultimate and serviceability limit state requirements.
4. Afterward, It is very important that the beam reinforcements are placed and arranged properly on site, to avoid construction errors.

Procedure:-

• First, we must open the challenge 7 page and download the challenge. After downloading the Challenge open it in the tabs 2018, as shown below.

• Next, we have to check the load combinations, as shown below.
  
  

• Next, we have to start the model design by selecting the 'analyze tab' option, as shown below.

• Next, we have to start the beam design by selecting the 'Start Design/Check' option, as shown below.

• After the completion of the beam design, we need to select the 'Display Design Info' option, as shown below.

• Next, the longitudinal reinforcement details will appear, as shown below.

• Next, we need to draw the Reinforcement diagram of 3 spans continuous beams along Grid-A, and also need to provide the reinforcement details.
• The maximum Ast for the bottom support is 1766 mm^2 and the bottom middle is 702 mm^2.
• The maximum Ast for the top support is 1889 mm^2 and the top middle is 453 mm^2.
• Now we provide 3-28`Phi`at the top and bottom, as shown in the below figure.
• Now we provide 1-8`Phi` at the top supports for the continuous beam, as shown below`

• Next we need to draw the Reinforcement diagram of 7 spans continuous beam along Grid-3, and also need to provide the reinforcement details.
• The maximum Ast for the bottom support is 1061 mm^2. and the bottom middle is 1493 mm^2.
• The maximum Ast for the top support is 1915 mm^2. and the top middle is 479 mm^2.
• Now we provide 3-22`Phi` at the top and bottom, as shown in the below figure.
• Next, we provide 1-10`Phi` and 1-12 `Phi`at the top supports and we provide 2-16`Phi` at the bottom middle for the continuous beam, as shown below.

• After providing the beam reinforcement details, we select the beam and right-click on the beam then the new tab appears, as shown below.
• Next, we need to click on the Details option in the Concrete beam design tab, as shown below.

• Next the Shear details will be visible, as shown below.
• As per the clause 6.3.3 the design force is172.38 kN.
• We got, Maximum Shear force = 130.8991 kN.

Conclusion:-

• The beams are designed successfully in detail from the Etabs software.
• Provided the details of longitudinal and shear reinforcement for the two continuous beams.
• And also calculated the value of maximum shear force in the continuous beams using the Etabs software.