Cutting length formula for stirrup-1
= [(2nos × a1) + (2nos. × b1) + (2nos. × hook length) - {(3nos. × 90° bend )+ (2nos. × 135° bend)}]
First, we will calculate the value of a1 & b1
a1 = [(column width ) - {(2nos. × clear cover) + (2nos.× 1/2 dia. of stirrup-1 bar)}]
= [ ( 750mm ) - { ( 2nos. × 40mm ) + ( 2nos. × 1/2 × 8mm )}]
= [ 750mm - { 80mm + 8mm }]
= [ 750mm - 88mm ]
= 662mm.
b1 = [ x + ( 2nos.× 1/2 dia. of mid bar.) + ( 2nos. × 1/2 dia of stirrup-1 bar )]
x = [column depth -{(2nos.×cover )+( 2nos.× dia. of stirrup-3)+ (2nos.× 1/2 dia. of outer bar)}] ÷ 3
= [ 600mm - {( 2nos. × 40mm ) + ( 2nos. × 8mm ) + ( 2nos.× 1/2 × 20mm )}] ÷ 3
b1 = [ x + ( 2nos.× 1/2 dia. of mid bar.) + ( 2nos. × 1/2 dia of stirrup-1 bar )]
= [ 161.33mm + ( 2nos. × 1/2 × 16mm ) + ( 2nos. × 1/2 × 8mm )]
= [ 161.33mm + 16mm + 8mm]
= 185.33mm.
The cutting length for stirrup-1
= [(2nos × a1) + (2nos. × b1) + (2nos. × hook length) - {(3nos. × 90° bend )+ (2nos. × 135° bend)}]
= [ (2nos.× 662mm) + ( 2nos. × 185.33mm ) + (2nos. × 10d ) - {( 3nos.× 2d ) + ( 2nos. × 3d )}]
Note:
1. Here,10d is taken for hook length.
2. We have deducted 2d for 90° bend -3nos., & 3d for 135° bend -2nos. as similar to the above drawing in all the 3 types of stirrups.
=[ 1324mm + 370.66mm + ( 2nos. × 10 × 8mm ) - {( 3nos.× 2× 8mm) + ( 2nos. × 3 × 8mm)}]
= [1694.66mm + 160mm - { 48mm + 48mm }]
= [1854.66mm - 96mm ]
= 1758.66mm.
2. Stirrup-2:
Cutting length formula for stirrup-2
= [(2nos × b2) + (2nos. × a2) + (2nos. × hook length) - { (3nos. × 90° bend )+ (2nos. × 135° bend)}]
First, we will calculate the value of b2 & a2
b2 = [(column depth ) - {(2nos. × clear cover) + (2nos.× 1/2 dia. of stirrup-2)}]
= [ ( 600mm ) - { ( 2nos. × 40mm ) + ( 2nos. × 1/2 × 8mm )}]
= [ 600mm - { 80mm + 8mm }]
= [ 600mm - 88mm ]
= 512mm.
a2 = [ y + ( 2nos.× 1/2 dia. of mid bar.) + ( 2nos. × 1/2 dia of stirrup-2 )]
First, we will find out the value of y
y = [column width -{(2nos.×cover )+( 2nos.× dia. of stirrup-3)+ (2nos.× 1/2 dia. of outer bar)}] ÷ 3
= [ 750mm - {( 2nos. × 40mm ) + ( 2nos. × 8mm ) + ( 2nos.× 1/2 × 20mm )}] ÷ 3
= [ 750mm - { 80mm + 16mm + 20mm }] ÷ 3
= [ 750mm - 116mm ] ÷ 3
= 634mm ÷ 3
y = 211.33mm.
a2 = [ y + ( 2nos.× 1/2 dia. of mid bar.) + ( 2nos. × 1/2 dia of stirrup-2 )]
= [ 211.33mm + ( 2nos. × 1/2 × 16mm ) + ( 2nos. × 1/2 × 8mm )]
= [ 211.33mm + 16mm + 8mm]
= 235.33mm.
The cutting length for stirrup-2
= [(2nos × a2) + (2nos. × b2) + (2nos. × hook length) - {(3nos. × 90° bend )+ (2nos. × 135° bend)}]
= [ (2nos.× 235.33mm) + ( 2nos. × 512mm ) + (2nos. × 10d ) - {( 3nos.× 2d ) + ( 2nos. × 3d )}]
=[ 470.66mm + 1024mm + ( 2nos. × 10 × 8mm ) - {( 3nos.× 2× 8mm) + ( 2nos. × 3 × 8mm)}]
= [1494.66mm + 160mm - { 48mm + 48mm }]
= [1654.66mm - 96mm ]
= 1558.66mm.
3. Stirrup-3
Cutting length formula for stirrup-3= [(2nos.× a3) + (2nos. × b3) + (2nos. × hook length) - {(3nos. × 90° bend )+ (2nos. × 135° bend)}]
First, we will calculate the value of a3 & b3
a3 = [(column width ) - {(2nos. × clear cover) + (2nos.× 1/2 dia. of stirrup-3)}]
= [ ( 750mm ) - { ( 2nos. × 40mm ) + ( 2nos. × 1/2 × 8mm )}]
= [ 750mm - { 80mm + 8mm }]
= [ 750mm - 88mm ]
= 662mm.
b3 = [(column depth ) - {(2nos. × clear cover) + (2nos.× 1/2 dia. of stirrup-3)}]
= [ ( 600mm ) - { ( 2nos. × 40mm ) + ( 2nos. × 1/2 × 8mm )}]
= [ 600mm - { 80mm + 8mm }]
= [ 600mm - 88mm ]
= 512mm.
The Cutting length of stirrup-3
= [(2nos.× a3) + (2nos. × b3) + (2nos. × hook length) - {(3nos. × 90° bend )+ (2nos. × 135° bend)}]
= [ (2nos.× 662mm) + ( 2nos. × 512mm ) + (2nos. × 10d ) - {( 3nos.× 2d ) + ( 2nos. × 3d )}]
=[ 1324mm + 1024mm + ( 2nos. × 10 × 8mm ) - {( 3nos.× 2× 8mm) + ( 2nos. × 3 × 8mm)}]
= [2348mm + 160mm - { 48mm + 48mm }]
= [2508mm - 96mm ]
= 2412mm.
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