CIVIL ENGINEERING FORMULAS

18

B 4

B 4

B

2

b

b

d

B

2

h H

h

B

(approx)

I = l

12

B

2

I = + +

t

4

t

2

3

3 π

16

I

c

2+ h

πB

4

π

I

Section Moment of inertia and section modulus Radius of gyration

+B^2 h h^3

h=H –

πB^3

16

πBh^2

2

+ 2b(h – d)

d^2

4

d^4 +b(h^3 – d^3 )+b^3 (h – d) I

= l

6 h

I

c

=^2 I

H + t

3 π

16

d^4 +b(h^3 + d^3 )+b^3 (h – d)

t

b 2

h

(^2) h^1
H

B

Corrugated sheet iron,

parabolically curved

t

b 1

3 I

t(2B + 5.2H)

r =

I =

=

h 1 =

(b 1 h 13 – b 2 h 23 ), where

(H+t)

h 2 = (H–t)

64

105

2 I

H+t

I

c

1

2

1

2

1

4

1

4

b 1 = (B + 2.6t)

b 2 = (B– 2.6t)