Luma Khalid

E-mail : luma.k@coeng.uobaghdad .edu.iq

Engineering Surveying 3rd Stage

Area of Cross ــ Section

C.L

Ground Line

Grade Line

1

S

1

S

اشكال المقاطع العرضية

• Cut Section

• Fill Section

• Side ـــ Hill Section

C.L

C.L

C.L

Computation of Elevation & Distance

• Compute missing Elevation & Distance of cross section

C.L

1

4

1

4

b/2=6 b/2

20 m ???

31.5

29.2

26.4 ???

ΔX2 ΔX1

ΔY1 ΔY2

A

B C D

F

G

Computation of Elevation & Distance

• ΔX2= 20-6 = 14 m

•1

4 = ΔY

ΔX

•1

4 = ΔY2

14

• ΔY2= 3.5 m

• Elevation point F= 31.5 – 3.5 = 28.00 m

• ΔY1= 31.5- Elevation point A =31.5-26.4=5.10 m

•1

4 =

ΔY1

ΔX1 =

5.10

ΔX1

• ΔX1= 20.4m

• Distance from A to G= ΔX1+b/2=20.4+6=26.4 m

Draw of cross- section 𝑓?

12 ,

𝑓3

3.5 ,

𝑓0.8

0.00 ,

0.00

2.0 ,

𝑐2

4.0 ,

𝑐4

?

C..L

0.8

Draw of cross- section

•𝑓?

12 ,

𝑓3

3.5 ,

𝑓0.8

0.00 ,

0.00

2.0 ,

𝑐2

4.0 ,

𝑐4

?

C..L

0.8

2.0

Draw of cross- section 𝑓?

12 ,

𝑓3

3.5 ,

𝑓0.8

0.00 ,

0.00

2.0 ,

𝑐2

4.0 ,

𝑐4

?

C..L

0.8

2.0

4.0

2

•𝑓?

12 ,

𝑓3

3.5 ,

𝑓0.8

0.00 ,

0.00

2.0 ,

𝑐2

4.0 ,

𝑐4

?

Draw of cross- section

C..L

0.8

2.0

4.0

2

b/2=3

???

4

C..L

0.8

2.0

4.0

2

b/2=3

???

4

Draw of cross- section 𝑓?

12 ,

𝑓3

3.5 ,

𝑓0.8

0.00 ,

0.00

2.0 ,

𝑐2

4.0 ,

𝑐4

?

Draw of cross- section

•𝑓?

12 ,

𝑓3

3.5 ,

𝑓0.8

0.00 ,

0.00

2.0 ,

𝑐2

4.0 ,

𝑐4

?

3

3.5

C..L

0.8

2.0

4.0

2

b/2=3

???

4

???

12

Draw of cross- section

•𝑓?

12 ,

𝑓3

3.5 ,

𝑓0.8

0.00 ,

0.00

2.0 ,

𝑐2

4.0 ,

𝑐4

?

C..L

0.8

2.0

4.0

2

b/2=3

???

4

???

12

3

3.5

Draw of cross- section C..L

0.8

2.0

4.0

2

???

4

???

12

3.5

3

Arithmetic Means

Shape of ground

Fora level section

fora three level section

fora Multi level section

One slope Two slope One slope Side ـــ Hill

C.L

C.L C.L

C.L

C.L

C.L

Fora level section

•1

𝑠 = ΔY

ΔX

•1

𝑠 = d

ΔX

• ΔX=s*d

• A= d(b+s.d)

C.L

S 1 d 1

S

b

ΔX =S.d S.d b

ΔY = d

fora three level section

• A= ½[b/2(dR+dL)+d(xR+xL)]

d

C.L

dR dL

xR xL

b/2 b/2

fora Multi level section

• Compute Area by coordinate

D

C

B

A

E

F

G

C.L

X - axis

Y - axis Y - axis

(0,0) (0,0)

One slope

• A= (h+𝑏

2𝑠)2(

𝑛2. 𝑠

𝑛2−𝑠2) - 𝑏2

4𝑠

h

n

1 1:n

b/2 b/2 C.L

1

S

1

S h

Two slope

• A=𝑊

2ℎ +

𝑏

2𝑠−

𝑏2

4𝑠

• W=w1+w2

• W1=𝑛1.𝑠

𝑛1+𝑠(ℎ +

𝑏

2𝑠)

• W2=𝑛2.𝑠

𝑛2−𝑠(ℎ +

𝑏

2𝑠)

1:n1

n2 1

1:n2

b/2 b/2 C.L

1

S

1

S h

1 1:n1

h1

h2

w1 w2

+

-

Two slope

• h1=𝑛1ℎ−

𝑏

2

𝑛1+𝑠

• h2=𝑛2ℎ+

𝑏

2

𝑛2−𝑠

• A=1

2ℎ +

𝑏

2𝑠

2(

𝑛1𝑠

𝑛1+𝑠+

𝑛2𝑠

𝑛2−𝑠) −

𝑏2

4𝑠

One slope Side ـــ Hill

• Ac=ℎ𝑐

2(

𝑏

2− 𝑑)

• Af=ℎ𝑓

2

𝑏

2+ 𝑑

• hc=𝑏

2−𝑛.ℎ

𝑛−𝑠𝑐

• hf=𝑏

2+𝑛.ℎ

𝑛−𝑠𝑓

h,wالاشارة موجبة والجزء الثاني سالب في حساب ال hاين يقع ال •

1:n b/2

b/2 C.L 1

Sc

1

Sf

h

hc

hf wc

wf

d