[Solved] The most suitable method for laying a curve is:- (2024)

Concepts:

The methods used in setting out a curve are classified as linear method and angular methods.

1. Linear method adopts the usage of chain or tape in which only distance can be found but not angles. Moreover, this process is used when accuracy is not required and speed of work is concerned.

The following are some of the linear methods used for setting out simple circular curves:

(i) Offsets from long chord

(ii) Successive bisection of chord

(iii) Offsets from the tangents–perpendicular or radial

(iv) Offsets from the chords produced.

2. Angular Methods: In these methods linear as well as angular measurements are used. Hence, the surveyor needs chain/tape and instruments to measure angles. Theodolite is the commonly used instrument.

The following are the angular methods which can be used for setting circular curves:

(i) Rankine method of tangential (deflection) angles.

(ii) Two-theodolite method

(iii) Tachometric method

The suitability of methods depends on the site conditions. For example, when the curve is to be set out over a rough ground then Theodolite method & Tachometric methodis used.

However, in general case two theodolite method is most appropriate as such in this error is not carried forward as each point is fixed independently.