Visayas State UniversityCollege of Engineering

Department of Geodetic EngineeringVisca, Baybay City, 6521-A, Leyte, Philippines

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GEng 111c- GENERAL SURVEYING 1

Laboratory Exercise No. 13

PROFILE LEVELING

Name: De Paz, Charlie May A. Date Performed: October 2, 2015 Score:____

Course & Year: BSCE-2 Date Submitted: October 12, 2015

I. INTRODUCTIONProfile leveling is a method of surveying that has been carried out

along the central line of a track of land on which a linear engineering work is

to be constructed/ laid.

It is important because the operations involved are about determining

the elevation of ground surface at small spatial interval along a line. The route

along which a profile is run may be single straight line, as in case of a short

sidewalk; a broken line, as in the case of a transmission line or sewer; or a

series of straight lines connected by curves, as in case of a railroad, highway

or canal.

II. LEARNING OUTCOMESAt the end of the exercise, the student will be able to:

Determine the elevations of ground points along the center line of a proposed roadway.

To plot the profile along the center line of a proposed roadway

III. MATERIAL AND TOOLS NEEDED

Automatic Level, Stadia rod, measuring tape, crayons or chalk

IV. PROCEDURE

Established stakes at every five (5) meter stationing (horizontal) along the center line of a 100 m or more (proposed).

Set up and level the instrument in some convenient location on one side of the proposed roadway.

Take and record a backsight on a rod held on a nearby bench to determine the height of the instrument.

Take and record intermediate foresights from as many center line points up to within practical limits of sighting.

When the rod has been advanced to a point beyond when further readings to ground points cannot be observed, established a turning point and take foresight on it to determine its elevation.

Transfer and set up instrument in another farther position and take backsight on the turning point just established. Then continue taking rod readings on ground points as before until the end of the roadway is reached; and

Tabulate observed and computed values accordingly.

V. RESULTS AND DISCUSSION

STA BS HI FS IFS ELEV

BM1 0.35 m 30.35 m 30 m

TP1 0.235 28.060 2.25 m 27.825

TP2 2.65 30.425 0.285 27.775

0+00 2.110 28.315

+05 1.545 28.880

+10 0.990 29.435

+15 0.400 30.025

TP3 2.26 32.40 0.285 30.140

0+20 1.695 30.705

+25 1.050 31.350

+30 0.395 32.005

TP4 2.39 34.73 0.060 32.340

0+35 1.645 33.085

+40 0.94 33.790

+45 0.195 34.535

TP5 2.385 36.755 0.360 34.370

0+50 1.723 35.032

+55 0.890 35.865

+60 0.220 36.535

TP6 2.790 39.455 0.090 36.665

0+65 2.250 37.205

+70 1.643 37.812

+75 1.150 38.305

+80 0.600 38.855

+85 0.172 39.283

TP7 1.270 40.554 0.171 39.284

0+90 1.0b2 39.472

+95 0.770 39.784

1+00 0.570 39.984

TP8 1.519 41.138 0.935 39.619

1+05 1.428 39.710

+10 1.260 39.878

+15 0.990 40.148

+20 0.480 40.658

BM2 0.042 41.096

The table above shows the data gathered in the exercise. The computed

value of benchmark two (BM2) which was 41.096 meters and all elevation (except

BM1) were found with the used of the data gathered of the backsight (BS) and

foresight (FS) and that the elevation of the benchmark one (BM1) was assumed to

be 30 meters. The height (HI) of the instrument was equal to the sum of the

elevation and the bakcsight in that specific station. And also, the other elevation

from TP1 to BM2 was computed in which elevation (ELEV) of the current station is

equal to the height of the instrument in the previous station minus foresight (FS) of

the current station (ex. HIBM1 – FSTP1 = ELEVTP1 ). The elevation in each interval of

five meter is equal to the difference between the height (HI) of the instrument and the

intermediate foresight (IFS).

The use of the elevation of each of the interval helps us determine how

inclined a proposed roadway is.

*The plotted profile of the proposed roadway is attached.

Solution:

VI. SKETCH

VII. REFERENCE

http://nptel.ac.in/courses/105107122/modules/module4/html/52/htm