Profiles (longitudinal section) & cross sections

In this lecture we will cover
Applications of levelling
Equipment and procedures
Purposes of levelling
Some definitions
Applications
Longitudinal sections and cross sections
Plotting the profile
Procedure of profile
Procedure of cross-section:
Plotting the cross-section:
Prepared by:
Asst. Prof. Salar K.Hussein
Mr. Kamal Y.Abdullah
Asst.Lecturer. Dilveen H. Omar
Erbil Polytechnic University
Technical Engineering College
Civil Engineering Department

1. Profiles (longitudinal section) & cross sections
1
Erbil Polytechnic University
Technical Engineering College
Civil Engineering Department
Surveying Engineering
Prepared by
Asst. Prof. SalarKhudhurHussein
Asst. Lecturer Mr. Kamal Yaseen
Asst. Lecturer Ms. DilveenH. Omar

2. In this lecture we will cover
Applications of levelling
Equipment and procedures
Purposes of levelling
Some definitions
Applications
Longitudinal sections and cross sections
Plotting the profile
Procedure of profile
Procedure of cross-section:
Plotting the cross-section:

3. Profiles (longitudinal section) and
cross sections
ThemainpurposesofthelevellingprocessisProfile(longitudinal)
andcrosssections,whichcanobtaintheformandthenatureofthe
earth'ssurfacealongthedesiredslopeline.Thislinemaybestraight
orcurvedandtheirrepresentationonamapwithasuitablescale.
Anditisrequiredtoobtain(find)formoftheearth'ssurfacewith
gettingtheelevationsofsomepointslocatedalongtheline,in
additiontothedistancesbetweenthosepoints.
Primaryuseisforutilities:
1-Highways2-Canals3-Sewers4-Watermains5-Sidewalks
etc..

4. Profiles Layout a 100 m long straight line (starting at your starting point)
and mark out stations by 20 m intervals along it
cross section
Mark out the reference line at 10 m wide cross section perpendicular to
the line at each of the 20 m stations.

5. Introduction abut Profiles (longitudinal section(:-
Profiles are the sections resulting from the leveling
process, which takes place in the longitudinal
direction of the project and along the path project
(central line). This can be done by measuring the
1-distances between the point
2-determining the elevations of those points.

6. Purpose of the profile
1 -Explain the nature of the earth's surface along the
project (along the central line).
2 –Calculate the quantity of volumes in the earth to
construct the project.
Specify the distancebetween the stations dependingon:
1 -The nature of the earth's surface.
2 -The cost of the survey process.
3 –The importance of the project (According to the
accuracy).

8. Site

9. Procedure of profile:
1 -Specify the direction of the longitudinal section (path section) by
selecting the location of the station, which should be equal in distances
(10-15, 20, 25, and 50) m according the nature of the earth's surface.
Scale 1/1000 horizontal and 1/100vertical

10. Setupthe instrument 40 to 50 m from your initial BM and take a BS and
Intermediate Fore Sights (IFS) of each of the 20 m stations and the
associated cross sections

12. 2 -Start leveling processby levelingthe stations fromknown
Bench mark (B.M)and this process is closed in order to
confirmthe accuracy of thesurvey process.

14. Point BS IS FS HI RL DistanceNote
1 - BM
HI = RL + BS
R.L=H.I-(I.S,F.S)

16. 3-Calculatedtheelevation(RL)ofthestationsinthe
tableandarecheckedfortheaccuracyofthework.
Point BS IS FS HI RL DistanceNote
1 0.663 99.42398.760 - BM
A 1.946 97.477 0
B 1.008 98.415 20
C 1.153 98.270 40
RL = HI -IS

18. Point BS IS FS HI RL DistanceNote
1 0.663 99.42398.760 - BM
A 1.946 97.477 0
B 1.008 98.415 20
C 1.153 98.270 40
D 1.585 97.838 60

20. Point BS IS FS HI RL DistanceNote
1 0.663 99.42398.760 - BM
A 1.946 97.477 0
B 1.008 98.415 20
C 1.153 98.270 40
D 2.787 1.585100.62597.838 60 TP
HI = RL + BS

22. Point BS IS FS HI RL DistanceNote
1 0.663 99.42398.760 - BM
A 1.946 97.477 0
B 1.008 98.415 20
C 1.153 98.270 40
D 2.787 1.585100.62597.838 60 TP
E 2.270 98.355 80
F 1.218 99.407 100
G 0.646 99.979 120

23. Point BS IS FS HI RL DistanceNote
1 0.663 99.42398.760 - BM
A 1.946 97.477 0
B 1.008 98.415 20
C 1.153 98.270 40
D 2.787 1.585100.62597.838 60 TP
E 2.270 98.355 80
F 1.218 99.407 100
G 0.646 99.979 120
SUM 3.4507.5952.231
Check 1
No. of BS = No. of FS
No. of BS = 2
No. of FS = 2

24. Point BS IS FS HI RL DistanceNote
1 0.663 99.42398.760 - BM
A 1.946 97.477 0
B 1.008 98.415 20
C 1.153 98.270 40
D 2.787 1.585100.62597.838 60 TP
E 2.270 98.355 80
F 1.218 99.407 100
G 0.646 99.979 120
SUM 3.4507.5952.231
Check 2
ΣBS –ΣFS = RL of last point –RL of first point
ΣBS –ΣFS = 3.450 –2.231 = 1.219
RL last –RL first = 99.979 –98.760 =1.219

25. Point BS IS FS HI RL DistanceNote
1 0.663 99.42398.760 - BM
A 1.946 97.477 0
B 1.008 98.415 20
C 1.153 98.270 40
D 2.787 1.585100.62597.838 60 TP
E 2.270 98.355 80
F 1.218 99.407 100
G 0.646 99.979 120
SUM 3.4507.5952.231
Check 3
ΣRL –RL first point = [Σ (No. of IS & FS x HI)]-Σ IS-Σ FS
ΣRL –RL first point = 689.741
[Σ (No. of IS & FSx HI)]-Σ IS-Σ FS
=[99.423x4 + 100.625x3] –7.595 –2.231 = 689.741

27. Plottingtheprofile
After obtainingthe levels ofthe stationson the path ofthe longitudinalsection,
draw thelongitudinalsection
1 -Drawthe elevation differences:
it is astraight horizontal line represents thenumber of horizontal distances
between thepoints (stations) along thehorizontal lineof the paperchartswith
suitable scale. andsetsthose distanceson the drawing
2-Drawtheelevationalongtheverticallineofthepapercharts
atascalelargerbecausethelengthofthesectionisbigcomparingtothe
differenceinelevationbetweenthestationsonthepath.
3-Setsthelocationofeachgroundpointonthepaperchartsbyusingthe
coordinates,whicharehorizontaldistanceandverticalelevations.

28. 4-Connectsthevariouspointsthathavebeendrawnwithsome
straightlineswithconsideringtheslopeoftheearth'ssurface
betweenconsecutivepointsofaregularslope.
5-Usuallytheselectionofhorizontalscaleissmallerthanthe
verticalscalebytentimes(1to10).
6-Drawsalinebelowthelevelofcomparingthreeparallellines
withanequaldistancesbetweeneachotherandusedtowrite
(1-Stations,2-Groundelevations,3-Gradeelevations).

30. Gradeline:-
Itissuggestedthattheelevationsofthegroundsurface(at
theprofileline)isdesignedbytheengineeraccordingtothe
technicalspecificationsoftheprojects.Thedifference
betweenthegradeelevationandgroundelevationatany
stationistheamountofcutandfillatthatstation.
1-Grade A = Ground A
2-Grade B= grade (A) + Slope ×Distance(A & B)
3-Grade C=grade(A) + Slope ×Distance (A & C

36. Cross-Sections
Cross-sectionisthesectionthatis(ortheelevationsaretaken)in
thedirectionperpendiculartothelongitudinalsectionatstations
onbothsidesofthecentrallineandspecifythepointsofthe
establishmentperpendicularonthelongitudinalsectionatthe
stationseitherby1-tape2-opticalsquare3-theodolite).

37. Cross-Sections
•Sections at right angles to the centerline of a proposed or
existing project such as a road
Scale 1/50 or 1/100 for both horizontal and vertical axes.

38. Specifythewidthofthecross-sectionandthedistancebetweenpoints
dependonthe
1-Thenatureoftheearth'ssurface.
2-Widthoftheproject(forexample,roadwidth)
Thepurposeofthecross-section:
1 -Explain the nature of the earth's surface on both sides of the longitudinal
section.
2 -Find the volume quantities of the earth to create the project.

39. Procedure of cross-section:
1 -Specify the direction of the longitudinal section (track section) by
selecting station locations to be at all equal distances (15, 20.25, and
50) m by the nature of the earth's surface.
2 –Specify points of the cross-section on both sides of the longitudinal
section by setting out a perpendicular line from the central points of the
line at the stations with using a right-angled triangle (3,4,5) or (6,8,10)
and specify the distance between the points at every (5 m or 10m
depending on the nature of the ground .

40. 3-Startthelevellingprocessbytakinglevelsofthestations
fromitisknownBenchmarkandthisprocessisclosedto
makesuretheaccuracyofthescanningprocess.
4-Calculatethelevelsofthestationsinthetableandthe
pointslocatedontherightandleftofthelongitudinalsection
istoprovidetheaccuracyofthework.

43. Draw a cross-section
After obtaining the elevations of the stations on the path of the
longitudinal section and the elevation of points, which are
located on both sides of the longitudinal section, and the grade
elevation, the cross sections is drawn.
The cross-sections drawing is similar to longitudinal sections
drawing, but just the same scale is used for both horizontal
distances and elevations of points (because the distance in this
case are not large relative to the elevation difference between
points), but the different scale is used in case of highway.