Cross Sectioning

In many projects, terrain information transverse to the longitudinal section (through profile leveling) is also required such as for highways, railways, canals etc. In those cases, surveying is carried out at right angle to the central line, generally, at regular interval is being carried out and is termed as cross- sectioning. If, for any reason, a cross-section is run in any other direction, the angle with the centre line is required to be noted. The observations are then recorded as being to the left or right of the centre line. The notes of the readings are maintained as shown in Table 14.2 for taking a cross-section along the stake point 4. Reduction of levels, Plotting etc. can be done as in case of profile leveling. A plotting of the cross section at stake 4 is as shown in Figure 14.3.

Table 14.2 Field book for Reduction of level

Pegs

Distance(m)
Direction
Staff reading (m)
Difference in elevation (m)
H.I (m)
R.L (m)
Remark
B.S.
I.S.
F.S.
Rise (m)
Fall (m)

A

 

 

3.005

 

 

 

 

108.620

105.615

B.M.

:

 

 

 

 

 

 

 

 

 

 

4

0+30

 

 

2.105

 

 

0.320

 

106.515

0m

 

 

 

 

1.850

 

 

 

 

106.770

2m left

 

 

 

 

1.725

 

 

 

 

106.895

4m left

 

 

 

 

1.680

 

 

 

 

106.940

6m left

 

 

 

 

1.985

 

 

 

 

106.635

2m right

 

 

 

 

1.875

 

 

 

 

106.745

4m right

 

 

 

 

1.780

 

 

 

 

106.840

6m right

B

0+40

 

2.875

 

3.105

 

1.000

108.390

105.515

T.P.1

:

 

 

 

 

 

 

 

 

 

 

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