Question

1. Steel tapes must be maintained and checked regularly for damages such as kinks and breakages. If a damaged steel tape is used for measurements describe the type of error(s)that would be observed. (0.5marks)

2. To meet the tolerance required for a surveying project, it is necessary to use a total station. An obstacle makes it impossible to obtain a direct line of sight. Explain one technique that you would use to establish the line of sight past the obstacle. Use a sketch if necessary (0.5marks)

3.Watch the video below which demonstrates the process of transferring levels or elevations.

https://www.youtube.com/watch?v=hAN9SAR7RZ4a.

a.Identify all the safety precautions taken by the survey crew.(1 mark)

b.The lead surveyor describes at least four challenges that the survey crew had to overcome during the survey process. Identify these challenges, and describe the errors associated with them. (1 mark)

c.Identify all activities performed by the survey party to ensure accuracy. Classify these activities according to the categories outlined in the Guidelines for Accurate Surveying. (3marks)

4.A surveyor completes a levelling circuit from a known BM at point A ( RL = 37.730 m). At the end of the survey, the surveyor finds out that the rod person moved the graduated staff before a BS value was taken at the third change point. The levels obtained are as follows: 1.857 ( RL = 37.567 m), (0.983, 0.354), 0.571, 1.011, 2.151, (1.124, x), 0.890, (0.543, 3.178), 3.808.

a.Assuming that the misclosure for the level circuit is 0.000 m, find the probable value of the missing BS value x.(2marks)

b.Is the value of x in part (a) acceptable? Explain.(1mark)

c.Book the levels, including the value of x calculated in part (a) using the HPC method and show all arithmetic checks. (1mark)

5.A surveyor conducted a cadastral survey of a property outlined by survey pegs at points A, B, C and D.The total station was used to measure the length of lines AB and DA however due to battery failure, lines BC and CD were measured using asuspended30-metre steel tape. The measurements obtained are given in the table below:

Line	Measured length(m)	Instrument used	Measured temp (0c)	Applied tension
AB	156.034	Total Station	22.2	-
BC	253.109	Taping	22.4	90
CD	121.198	Taping	22.1	90
DA	106.075	Total Station	22.0	-

a.If the tape was standardised under a tension of 50 N at 20°C, apply the necessary corrections and compute the actual length of lines BC and CD.(1mark)

b.It is known that angle DAB is 102°15′40′′. After the survey, it is observed that the total station at point A is off the survey peg, coinciding with a point A′such that angle DA′B is 102°26′42′′. Find the length of distance AA′.(2mark)

c.Determine the actual length of lines AB and DA. (2marks)

Take:

Gravitational acceleration,g= 9.81 m/s2

Cross-sectional area of the tape, A= 3.15 mm2

Mass of the tape, m= 0.02 kg/m

Coefficient of linear thermal expansion, K= 0.9 × 10–6per °C

Young’s modulus, E= 14.8 × 104MN/mm2

Answer 1

Questuin 1

Types of error occurred are

(1) Instrument error: this type of error occurred by use of faulty chain due to defect in its manufacturing or some other damages

(2) Natural errors: This types of errors caused by

• defect in steel tape due to change in temperature
• elongation of tape due to tension

(3) Personal errors:

• poor alignment while surveying
• holding of tape is not straight due to defect
• faulty reading Measurements of tape

(4) Compensating errors:

• this types of errors occurred in one direction due to defects of tape and tend to compensate
• it is not make the results too large or too small
• Fractional parts of tape is not correct or damaged

(5) Cumulative errors:

• this types of error occur in same direction and are tend to add up or increasing
• if the total length of tape is too shorter than standard length because of some defects
• if the total length of tape is too longer than standard length