ENGINEERING SURVEYS FOR HIGHWAY LOCATION:-

The surveys to be carried out are:

MAP STUDY: - with the help of topographic map it is possible to suggest the likely routes of the road. In India, topographic maps are available from the survey of India with 15 of 30 m contour interval. The main features like rivers, hills, valleys, etc., are also shown on these maps.

RECONNAISSANCE: - IT IS a rapid and rough survey. During the survey, the physical characteristics of the areal are inspected and the proposed route is thoroughly examined. it is done without accurate instruments. Clinometers are used to determine the slopes of the ground. It provides additional information not available in top sheets.

Objects: -

i. To study the feasibility or practicability of the proposed route

ii. To reduce the number of alternative routes to the minimum to select the best 2 or 3 routes.

PRILIMINARY SURVEY: - This survey can be started on the basis of reconnaissance. It consists of detailed survey of the alternative routes selected. After reconnaissance. It is done by using the instruments such as chain, compass, tape, level & theodolite.

Objects: -

a. To select the best route.

b. To determine the centre line to be followed

c. To collect are additional information found necessary after reconnaissance.

FINAL LOCATION AND DETAILED SURVEY: - The alignment finalized after the preliminary survey is to be first located on the field by established the centre line.

This is done accurately by using instruments. The final route selected after the preliminary survey is surveyed and located on the ground.

Objects:-

1. To establish temporary bench marks

2. To collect information required for

3. The preparation of working drawings

4. The preparation of detailed estimates

5. The design of road & bridges

6. Preparing specifications

7. Land acquisition