1. USE OF PLANIMETER,COMPUTATION OF VOLUME FROM CROSS SECTION
MR.VRAJESH PATEL1 MR.JAY PRAJAPATI2 MS.KINJAL SHAH3
MS.POOJA SHAH4
(1) Student,Civil engg.Department [ ]
(2) Student,Civil engg.Department [ ]
(3) Student,Civil engg.Department [ ]
(4) Student,Civil engg.Department [ ]
VADODARA INSTITUTE OF ENGINEERING
Guided by :- Prof.Pranav. D. Bhangaonkar

2. CONTENTS Introduction Use of Planimeter Computation of volumes
Volume of cross section

3. Introduction, Use of Planimeter

4. Introduction It is also known as Amsler’s Planimeter.
Used to find areas of irregular figures.
e.g.:- Areas of Contour in determining the capacity of reservoir
It gives great accuracy

5. Finding Area of given Plan
Make adjustment of tracing arm.
Anchor should be placed conveniently so that tracing is done accurately.
Before starting the tracing work, initial and final reading should be noted.
While moving the tracing around periphery note the number of times zero of counting disc has passed the fixed index marks
Compute area by:
A=M(F.R-I.R+-10N+C)

7. Zero Circle
The zero circle is obtained by moving the tracing arm point in such a way that the tracing points make an angle of 90 with anchor arm.

8. Computation of Volumes
Introduction , Classification: Methods of Calculation
Computation of Volumes

9. Introduction: Computation of Volume
Computation of volumes is required for heavy earth work for roads and channels.
Methods of computation of volume are as below:
1. Average height method
2. Average area method
3. Trapezoidal formula
4. Prismoidal formula

10. Average Height Method

11. Average Area Method

12. Trapezoidal Formula

13. Prismoidal Formula

14. Note
Prismoidal formula can be applied for odd number of sections only.
Prismoidal formula is more accurate than the trapezoidal formula.
To have more accuracy by trapezoidal formula, prismoidal correction should be applied.

15. Prismoidal Correction

16. Volume of cross section
Introduction, Classification of Cross-Section: Level Section, Two-Level Section, Side hill two-level Section, Three-level Section, Multi-level Section
Volume of cross section

17. Introduction: Volume from Cross-Section
Most widely used method
It is carried out by dividing the total volume into series of solids by planes of cross-section.
Area along the line is calculated by standard formula and volumes of the prismoids is calculated either by Trapezoidal Rule or Prismoidal Rule.

18. Classification of Cross-Section
Level Section
Two-Level Section
Side hill two-level Section
Three-Level Section
Multi-Level Section

19. Computation of volume from cross section
For estimation of the volume of earthwork, cross-section are taken at right angle to a fixed line which runs longitudinally through out the earthwork.
The spacing of the cross-sections will depend upon the accuracy required and character of the ground
The volume of earthwork between successive is determined from the areas of various cross-section

21. Computation of volume can be done by following Three method.
(1)from cross section
(2)From spot level
(3)From contours
First method is useful for computing earthwork involving in road/rail/canal/sewage works.

22. Second method is useful for finding earthwork in foundation of large building.
And third method are useful for finding capacity of reservoirs.

23. Level Section It is used when ground is well leveled. where,
A= Area of ABDE
b=width at formation level
h=depth of cutting on centre line
s=inclination of side slopes

24. References Surveying and Leveling- By N. N. Basak
Surveying and Leveling-By T.P Kanetkar and S.V Kulkarni

25. Thank You