ROAD PROFILING, CROSS SECTION & SETTING OUT SEWER LINE REPORT

1. JJOOMMOO KKEENNYYAATTTTAA UUNNIIVVEERRSSIITTYY OOFF
AAGGRRIICCUULLTTUURREE AANNDD TTEECCHHNNOOLLOOGGYY
Setting Trends in Higher Education, Research and Innovation
School of Civil Engineering and Geospatial Engineering
Bachelor of Geomatics Engineering and Geospatial Systems
Bachelor of Geospatial Information Science
INTERNAL ATTACHMENT
Group 4
Fieldwork 4 Report
ROAD PROFILING, CROSS SECTION & SETTING OUT
SEWER LINE
Student Name Registration Nº
Gavin Kendo ENC221-0330/2016
Stildon Kimani ENC222-0337/2016
Tarri Halakhe ENC221-0159/2016
Calvin Kiplimo ENC222-0168/2016
Ivy Njeri ENC221-0157/2016
Raymond Rawlings ENC222-0362/2016
Sharon Mwanza ENC221-0098/2016
Barasa Samuel ENC222-0351/2016
Faith Mwende ENC221-0311/2016
Kosgei Antoney ENC222-0354/2016
Paul Akelo ENC222-0331/2016

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Introduction
In profile leveling, you determine the elevations of a series of
points lengthwise along a road. Profile are plotted such that the
vertical scale is exaggerated in relation to the horizontal scale so
that the difference in the elevation are accentuated. The line along
which the profile is to be taken may be marked prior to the survey.
This is normally done in 100-foot stations. A rod reading is taken at
each full station and at each major break in the ground slope. This
procedure differs from the running of a circuit level in that more
foresights are taken from each set-up. The stations of the breaks in
slope are taped and referenced from the full stations established
along the profile line
In cross-section leveling, you determine the elevations of
points on a succession of lines running at right angles to the
lengthwise line of the highway. Cross sections are necessary for
measurement of earthwork volumes in roadway construction. They
are profile views of the ground, perpendicular to the centerline or
base line, and indicate ground elevations at points of change in the
ground slope. Original cross sections indicate the profile of the
original ground before the ground is disturbed. These
measurements may be used for primary design, estimating
volumes, etc. Borrow pit original cross sections are taken after
stripping has occurred.
Cross sectioning is a method of leveling to know the nature of
ground on either side of the centerline of the proposed route and
leveling is carried out along this cross section. During location and
construction of highways, Rail tracks sewers and canals mark are
placed at various aligned points.
Cross sections are the sections run at right angles to the
centerline and on the either side of it they are taken at each 5,10m
station on the centerline. The length of cross section depends upon
the nature of the work.
Manhole is a small covered opening in a paved area allowing
access beneath, especially one leading to a sewer.
Drainage set-out surveys generally provide the set-out
required for the designed horizontal and vertical alignment of a road

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or drain. Survey can consist of a peg or mark placed indicating an
offset and level at incremental distances along the designed
alignment. This information will determine the required cut/fill
required, to meet the design criteria. Both road and drainage set-out
generally will require as-built surveys to be carried out. This
information can be used to calculate how close the road has been
built to design, and if it meets the design tolerances and standards.
Volumes of material used and required can also be determined from
these surveys and are useful in accounting for materials used and
also forecast what cut or fill volumes remains.
Objectives:
 To determine the elevations of the ground surface.
 To set out sewer line and Manholes.
 Carry out accurate setting out.
 Carry out all the necessary calculations to establish
the setting-out points.
 Work as a team in order to execute a large-scale
surveying work.
 Produce and present an engineering report on an
engineering survey work.
 To find elevation of longitudinal and transverse
stations for making profile and cross sections.
Instruments to be used:
1. Level.
2. Staff.
3. Tripod.
4. Measuring Tape.
5. Ranging Rod.

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Fig1.0 Area of work
Procedure
1. Fix the stations for the centerline 20m each from 0+00 to
0+400 by measuring tape.
2. Then for each station mark 5R, 10R, 5L and 10L
perpendicular to the longitudinal line.
3. Instrument level is setup at convenient positions near bench
mark.
4. First sight of B.M (point of known elevation) is taken and
reading is entered in back Sight column.
5. If distance is large instrument is shifted, the instrument
becomes turning point (or) changing point.
6. After setting up instrument at new position,
performing temporary adjustment and Take back sight as
turning point.
7. Thus, turning point will have both back sight and fore sight
readings.
8. Take readings for near stations and enter the readings in
intermediate column.
9. Then take another turning point and shift to new location for
other stations.

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10. Lock the leveling operation by returning to the first point
(BM).
11. Readings are entered in a tabular form given below and
Reduced levels are calculated by height of instrument method.
Sources of Error
 They are staff readings and tilt of the pole or staff. Observer
tends to make wrong observation when observing the staff
reading, they might misread the staff marking scales and this
brought to the crucial error along the booking process.
Besides, the tilting of the staff rod can influence the accuracy
of the height readings taken from the staff. When the staff is
not truly vertical (90º) or almost to it, the reading taken is
incorrect and lead to the failure of tachometry process.
 Errors in conducting tachometry survey also caused by
natural causes. These include errors due to high winds.
During high winds, it is difficult to keep the staff vertical and
read it accurately. Works should be undertaken during hot
mid-day period. In very hot conditions, the instrument should
be protected with an umbrella to avoid errors due to the
unequal expansion of different parts of instruments. Work
may also be hampered by bad visibility due to strong sunlight
and glare.
 Error due to manipulation and sighting are inaccurate leveling
of the instrument, inaccurate reading of horizontal line and
vertical angles, poor focusing errors, inaccurate bisection of
the target, inaccurate reading of the staff intercept and lastly
due to errors in holding the staff.
 Instrumental errors. They are those caused by the adjustment
of the instruments used or faults in them. Any errors in these
measurements have serious implications in the heights and
distances measured with the instruments. To avoid such
errors, the following points should be taken care of:

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a) The level should be in perfect adjustment for taking
observation.
b) The altitude bubble should be at the centre of its run
while reading the vertical circle for angles. Any index
error should be detected and eliminated or accounted for.
c) The multiplying and additive constants of the instrument
should be periodically checked to see that they indeed
have the values that are being used.
d) The stadia rod (staff) should be accurately divided into
parts. The graduations should be uniform and free of
errors. They should be marked bold for greater visibility
from a large distance.
Conclusion
In this experiment we worked in field and we obtained desired
data. From the profile run, we know the center-line elevation at
each station. And we take cross-section elevations at (0+20 m) for
center line and both sides of the center line.
On the plot of the profile we note that the road line is slope, it
decreases when we move from left to right.
From the field sheet we see the cross-section of the road and
we note that the center line is higher than both sides (right and
left).