Fieldwork No.
___ Date:______
PROFILE LEVELING
Name:_______________________________________ Course/Year:_____
Group No.:________
I. Objective:
a.) To determine the elevation of ground points along the center line of a
proposed roadway.
b.) To Plot the profile along the center line of a proposed roadway.
II. Equipment/Apparatus:
Engineer’s Level or Automatic Level, Hubs or Pegs, Range Poles, Leveling Rod,
Marker, Steel Tape, Chaining pins.
III. Procedure:
1.)Profile Leveling
a.) Establish stakes at every full station along the center line of a 500 m long
proposed roadway at an interval of 10 meters.
b.)Set up and level the instrument in some convenientlocation on one side of the
proposed roadway.
c.)Take and record a backsight on a rod held on a nearby benchmark to
determine the height of instrument.
d.)Take and record the intermediate foresights from as many centerline points
up to or within practical limits of sighting.
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e.)When the rod has been advanced to a point beyond which further readings to
ground points cannot be observed, establish a turning point, and take a foresight on it
to determine its elevation.
f.) Transfer and set up the instrument in another farther position and take a
backsight on the turning point just established. Then continue taking rod readings on
the ground pointsas before until the end of the roadway is reached.
g.)Tabulate observed and computed values accordingly. Refer to the
accompanying sample format for the tabulation of field data.
Tabulation of Data gathered
Station Back Height of Fore Intermediate Elevatio Remarks
Sight Instrument Sight Fore Sight n
(BS) (HI) (FS) (IFS)
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2.) Plotting the Profile.
a.) Plot the observed and completed data (stationings and elevations of full and
plus stations) on a graphing paper. Horizontal lines represent the intermediate foresight
points with their interval distances. Vertical lines represents the elevation of each
ground points.
b.)Use a scale of 1:1000 for plotting the horizontal distances and 1:100 for the
vertical distances.
c.) Connect the plotted elevations for the profile by a smooth curved line drawn
freehand.
d.)Label the plot of the profile accordingly. The stationings, elevations, horizontal
and vertical scales must be indicated.
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E
L
E
V
A
T
I
O
N
HORIZONTAL DISTANCE OF STATIONINGS AT 10 METERS INTERVAL
E
L
E
V
A
T
I
O
N
HORIZONTAL DISTANCE OF STATIONINGS AT 10 METERS INTERVAL
E
L
E
V
A
T
I
O
N
HORIZONTAL DISTANCE OF STATIONINGS AT 10 METERS INTERVAL
E
L
E
V
4
A
T
I
O
N
HORIZONTAL DISTANCE OF STATIONINGS AT 10 METERS INTERVAL
IV. Computations:
1.) Computing Height of Instrument and Elevation
The theory involved in profile leveling is exactly the same in differential
leveling. A backsight is taken on a benchmark or point of known elevation to
determine the height of instrument and the elevation of the ground points are
calculated by subtracting the corresponding rod readings from the height of
instrument.
2.) Determining difference in elevation.
a. The difference between the sum of all bacsights and the sum of all
foresights is equal to the error of closure, or equal to the difference in
elevation between the initial benchmark and the final point.
b. The intermediate foresight reading subtracted from the height of
instrument gives the ground elevation of a plus station.
c. The difference between the elevation of any two points that are
obtained at the same set up of the instrument is equal to the
difference between the foresights taken on these points.
V.Guide Questions:
1.) In setting the leveling instrument, is it important that the leveling bubbles be
balanced? Why?
2.)What is the implication if the instrument is not well balanced?
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3.)Cite an example of the importance of this fieldwork for you as future
Engineers.
VI. Observations
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VII. Conclusion:
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VIII. Recommendations:
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