Test: Balancing the Traverse - Civil Engineering (CE) MCQ

Since Graphical method involves a rough calculation and plotting of traverse directly from the field notes, it is not necessary for calculating latitudes and departures.

Bowditch’s and Transit method involves the usage of correction of latitude and departure formulae. Graphical method uses Bowditch’s formula for solving graphically whereas Axis method is used in case of length corrections which are having accurate angles.

Due to the equal precision of the linear and angular measurements, it can be termed as compass rule.

While traversing, in most of the cases, the traverse will be closed by polygon. It is the only way of applying corrections for latitudes and departures i.e., ∑L = 0 and ∑D = 0 and for eradicating closing error.

The check applied for finding the sum of interior angles is equal to (2n-4) right angles. Similarly, the check for exterior angles is equal to (2n+4) right angles.

A Traverse computation involves a lot of procedure which requires accurate values for further processing. So, first we need to check and adjust the interior angles for continuing the remaining process.

Due to the precision of angular and linear measurements obtained by Bowditch’s method, it is more commonly used, but Transit method will be able to deliver less affected measurements due to corrections applied. Axis and Graphical methods can be applied whenever rough measurements are necessary.

The consecutive co-ordinates which are obtained from the latitudes and departures will be able to derive independent co-ordinates.

Total error in latitude = -264.97 + 182.96 + 79.62 = -2.39
Total perimeter of traverse = 125.91 + 198.57 + 229.88 = 554.36 m
Sum of latitudes = 264.97 + 182.96 + 79.62 = 527.55
Now, correction for latitude of BC = latitude of BC * total error in departure / sum of latitudes = 182.96 * (- 2.39) / 527.55 = – 0.829 m. If error is negative, correction is positive
Corrected departure = 182.96 + 0.829 = 183.789.

Total error in departure = -228.92 + 326.62 – 98.69 = -0.99
Perimeter of traverse = 114.99 + 217.57 + 319.31 = 567.29 m
Correction for departure of AB = length of AB * total error in departure / perimeter of traverse = 199.85 * -0.99 / 567.29 = -0.349 m. Error is negative then correction is positive i.e., correction = 326.62 + 0.349 = 326.969.