survey report levelling

NO. CONTENT PAGE1 TABLE OF CONTENT 1

2 AIM AND THEORY 2

3 TOOL AND MATERIAL 3

4 PROCEDURE 4

5 DATA OBSERVATION AND CALCULATION

5 - 6

6 CONCLUSION 7

7 REFERENCE 8

ENGINEERING SURVEYING

PROJECT 1 : LEVELLING

AIM:

To measure and investigate the height of structure laboratory.

THEORY:

Levelling is a general term used in land surveying that applies to vertical measurements Vertical measurements are made and referenced to datum, as elevations The reference datum might be an arbitrary elevation chosen for convenience or a very

precise value determined after lengthy studies The standard reference datum used throughout California is mean sea level, based on the

National Geodetic Vertical Datum. Three methods used to measure differences in elevation are direct vertical measurement,

trigonometric levelling, and differential levelling. It is important to understand the procedure, equipment and note keeping format used for

each method. Levelling is the determination of the elevation of a point or difference between points

referenced to some datum. A surveying operation carried out to determined the elevation of points or to find the

difference in elevation of points.

TOOL AND MATERIAL:


TOOL

i. Tilting level

A surveyor's level with a bubble mounted on the telescope and a provision for

slight tilting of the telescope and level.

The upright axis of the unit does not need to be vertical, but the level and

telescope must be precisely aligned.

Features: Clear and easy surveying, high durability, reliable performance.

ii. Tripod stand

A tripod stand is a device used to support any one of a number of surveying

instruments, such as theodolites, total stations, levels or transits.

Features: Customized colors are welcome, with needle locking device, high

precision and portable item.

iii. Staff (Levelling Rod)

A level staff, also called levelling rod, is a graduated wooden or aluminum rod, the

use of which permits the determination of differences in elevation.

iv. Staff bubble

Air bubbles are used to ensure staff erected vertically.

Usually placed on the side of the staff.

PROCEDURES:

1. Place the staff over point A and point B of structure laboratory.


2. The instrument was set up and prepared for the fly levelling process at random distance.

3. A staff was placed on the Temporary Bench Mark (TBM) and take a sight on the staff,

that reading is called Back Sight (BS).

4. Then, move the staff to a new position at point A and take the reading, this will be a

Intermediate Sight (IS).

5. Move the staff to a next position at point B and take the reading, this will be second


6. The staff was then placed at the electric pole to get Fore Sight (FS) reading.

7. After that, move the instrument to a new position at the centre of field and take the

reading on the previous position of the staff. This position of staff is known as Change

Point (CP) and this reading will be Back Sight (BS).

8. Move the staff to a new position at point C and take the reading, this will be third


9. Then, move the staff to a next position at point D and take the reading, this will be fourth


10. The staff was then placed near the fire hydrant to get Fore Sight (FS) reading.

11. After that, move the instrument to a new position and take the reading on the previous

position of the staff. This position of staff is known as Change Point (CP) and this

reading will be Back Sight (BS).

12. The reading is taken at the same Temporary Bench Mark (TBM) as Fore Sight (FS) to

finally complete the flying process.

13. The readings that were taken, were all recorded.

14. The data collected, was then calculated to find the Reduced Level (RL), rise and fall,

correction and correction RL.

DATA AND OBSERVATION:

STATION B.S I.S F.S RISE FALL R.L CORR. CORR. REMAKRS


(m) (m) (m) (m) (m) (m) (m) RL (m)

1 0.80 43.035 TBM (43.035m)

2 0.100 0.700 43.735 +0.128 43.863 A

3 0.130 0.030 43.705 +0.128 43.833 B

4 1.24 1.230 1.100 42.605 +0.128 42.733 C.P

5 0.145 1.095 43.700 +0.256 43.956 C

6 0.120 0.025 43.725 +0.256 43.981 D

7 1.02 0.985 0.865 42.860 +0.256 43.116 C.P

8 1.230 0.210 42.650 +0.385 43.035 E

CALCULATION:

DATA:

STATION BS (m)

IS (m)

FS (m)

RISE(m) FALL(m)

R.L(m) CORR.(m)

CORR. RL(m)

REMARKS

1 0.8 43.035 TBM 43.035

2 0.10 0.7 43.735 +0.128 43.863 Titik A3 0.128 0.13 0.03 43.705 +0.128 43.833 Titik B4 1.24 1.23 1.10 42.605 +0.128 42.733 (C.P)5 0.145 1.095 43.700 +0.256 43.956 Titik C6 0.12 0.025 43.725 +0.256 43.981 Titik D6 1.02 0.985 0.865 42.860 +0.256 43.116 (C.P)7 1.23 0.21 42.65 +0.385 43.035 Titik E

CALCULATION:

Height difference between T.B.M with point A= 0.8 – 0.10= 0.7 m

Point A higher than the T.B.M, the positive (+ ve) listed in the column rises So 0.7 is located at column rise

Height difference between point A with point B


= 0.10 – 0.13= (-0.03)

Point B lower than the point A, the negative (- ve) listed in the column fall So (-0.03) is located at column fall

To find reduce level from point AReduce level from point A = Reduce level T.B.M + Rise= 43.035 + 0.7= 43.735 m

To find reduce level from point BReduce level from point B = Reduce level T.B.M + Fall=43.735 + (-0.03)= 43.705 m

To find a correction:=Point E - Reduce level from T.B.M= 42.65 – 43.035= (-0.385) / 3= 0.128 m

Station 1 = 0.128 m Station 5= 0.128 x 2

= 0.256 m Station 7= 0.128 x 3

= 0.385 m To find a correction reduce level

Station 1 = 43.735 + 0.128 = 43.863 m

Station 5= 43.700 + 0.256= 43.956 m

Station 7= 42.65 + 0.385= 43.035 m

CONCLUSION:

For the conclusion, we can know about a procedure to reading of the levelling. We can get any

knowledge to setup the level of land and to study the shape of earth surface. Accurate reading


sometimes there is an error in the reading; the earth is not flat or uneven terrain. besides that,

there is an error in the way in setting up tools. To study the shape of earth surface at the area on

the topography map and to find difference in level between two points.

We also can use tachymetry to rapid surveying, by which the positions, both horizontal and

vertical of points on the earth’s surface relatively to one another are determine without using a

chain or tape a separate levelling instrument. We can use tachymetry to prepare of topographic

map where horizontal and vertical distances are required to be measure.

And last, we can know about a procedure to reading of the compass. We can get any knowledge

to setup the level of land and to study the shape of earth surface. Accurately reading sometimes

there is an error in the reading; the earth is not flat or uneven terrain. Besides that, there is an

error in the way in setting up tools.

From that we will get an objective of this project.

REFERENCE:

TOOL


TILTING LEVEL STAFF (LEVELLING ROD)

Tripod Stand Staff bubble


survey report levelling

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