Reinforcement detailing of Columns from ETABS output

1 Ans :

AIM:

• The ETABS file for a G+4 building is provided. Run the analysis and design the RCC Moment Resisting Frame. The following challenge deals specifically with two columns at the following grid intersections.
• Provide details of longitudinal reinforcement for the two columns, from foundation to terrace level. Sketch the column cross sectional & elevation details or draft it using autocad software.

INTRODUCTION:

• Before run the ETAB model file check the condition like materials , Frame assing values etc.
• Then run the model using F5.
• Once the model is run then goto Concrete frame design and click on it .
• Open the longitudinal reinforcement and shear reinforcement values from the design details from concrete frame design in the ribbon tab.

PROCEDURE :

• The longitudinal and shear reinforcement values are taken in account and design the column structure from it.
• The minimum longitudinal reinforcement required as per IS 450 - 2000 Clause 26.5.3.1
• AS = 450 *650 *.80/100 = 2340 mm
• Minimum Shear reinforcement required as per IS 13920 -2016 Clause 7.4.2
• Maximum 300 mm of 8 mm dia
• Development length as per IS 456 -2000 clause 26.2.1
• Ld = 41 * dia of bar
• Column longitudinal reinforcement
• 
• As per the value of 7027 = we are placing 16 nos of 25 mm dia. ( That is 16*490 = 7840 )

• Column shear reinforcement
• 
• The shear value maximum is along major axis , ( on major axis we are providing 6 legs )
• The shear value minimum is along minor axis , ( on minor axis we are providing 4 legs )

• Special column confinement reinforcement from IS 13920 -2016 clause 8.1
• L0 = Column and beam joints area
• It has minimum 450 mm
• It may be maximum dimension of the column
• 1/6 of clear span of the column

• Confinement spacing should not more than,
• 100 mm
• Minor dimension of the column / 4
• 6 times the main dia of the column.

• The amount of confinment rebars ,
• As = 0.18 * h*Sv*(Ag/Ak-1)*Fck/Fy
• As = 0.05*h*Sv*Fck/Fy
• The rebars required are 169 mm.

RESULT :

• As per given detail the ETABS file is executed and the Column reinforcement is designed as per IS 456 -2000 and IS 13920 -2016, for both Longitudunal and transfers shears rod.