Describe the different surveys to be carried out for the highway projects.
i) Reconnaissance
ii) Preliminary Survey
iii) Location Survey
i) Reconnaissance:
During the reconnaissance survey the following factors have to be taken into consideration.
Ø Obstructions along the route.
Ø Gradients and length of curves.
Ø Cross drainage works.
Ø Soil type along the route.
Ø Sources of construction materials and
Ø Type of terrain.
ii) Preliminary Survey:
The preliminary survey in a highway project is done with the main objectives
Ø Various alternate arrangements
Ø Estimate the quantity of earth work materials and other construction aspects
Ø Compare different proposals.
The following surveys are constructed
Ø Primary transverse
Ø Topographical surveys
Ø Levelling work
Ø Hydrological data
Ø Soil surveys.
iii) Location Survey:
The final alignment decided after the preliminary survey is to be first located on the field by
establishing the centre line. Next the detailed survey should be carried out.
The detailed survey involves:
Ø Fixing temporary bench marks along the route for every 300 m.
Ø The cross sectional details are taken for 30 m on either side of the central line.
Ø All details of cross drainage works are taken.
Ø Topographical details are taken.
Ø Detailed soil survey is carried out.
