Element of Civil Engineering Bridge course

1. AREA & VOLUME CONCEPTS
Kaustubh J. Sane
HJD institute of Technical Education &
Research, Kera

2. • Calculating area and volume of simple geometrical shapes
• This is an analytical method for computing the area of plot
and converted to graphic method.
• The area is divided into suitable geometrical figures like
triangle, square, rectangle.
• Area of triangle= √s(s-a)(s-b)(s-c)
• Area of triangle= ½*b*h
• Area of triangle= ½*a*b*sin Ө, Ө is angle between two
sides of triangle.

3. • Calculating area of plot with irregular boundary from
field notes
• Area of field can be directly calculated from
field notes.
• During survey work whole area is divided into
some geometrical figures like triangles,
rectangles, square, or trapezium.

4. • Calculating area of plot with irregular boundary
• The area may be calculated in following ways
– Considering entire area
• By dividing the area into triangles
• By dividing the area into squares
• By drawing parallel lines and converting them to
rectangles
– Middle area+ boundary area

5. • Triangle area= ½* base* altitude

6. • Preparing squares of equal area 1cm or 1m
• Area= nos. Of square * unit area

7. • Area= ∑length of rectangles*constant depth

8. Linear measurement
• To measure a horizontal distance between two
points in surveying work is called as linear
measurements.
• Two methods
– Direct- computing the actual distance with help of
chain and tape
– Indirect- computing is carried out with help of
optical instruments in areas where to reach and
measure is difficult to carried out.

9. • Use of linear measurements
– Area calculation of site
– Volume calculation of site
– Dividing the site in regular shapes with
measurements.
• Instruments used for linear measurement
• Chain
• Tape

10. • Chain
– Metric chain- length of link is 20cmmay be of 20m
or 30m in total length.
– Gunter’s chain- 66feet long consist of 100 links
each of 0.66feet. Here 10square chains = 1acre;
10chains = 1 furlong, 8 furlong= 1mile
– Engineer’s chain- 100ft long, 100 links, each link is
of 1ft.
– Revenue chain- 33ft long, with 16 links, used for
distance measurements in ft and inches
– Steel band chain- more accurate than others, it
may be of 20m, 30m. And have marking at every
20cm

11. • Tapes-
– Cloth tape- 10, 20, 25 or 30m
– Fiber glass tape- flexible non conductive
– Metallic tape
– Steel tape
– Invar tape

12. • ELEVATION:
• Introduction to leveling & contours
• Define contour line
• Uses of contour map