Test: Engineering Surveys For Highway Alignment

The surveys are completed in 4 stages namely map study, reconnaissance, preliminary survey and detailed survey.

All the maps related to topography in India are prepared by survey of India, NHAI is for highway alignment and geological survey of India for any rocks exploration, government of India is the finance aid for all.

The reconnaissance survey consists of studying the details in the field roughly which are not covered in the map study.

 The preliminary survey consists of collecting topographical data, soil survey and other data, in reconnaissance survey rough survey is done, map study is for plan.

A traverse is a closed loop used for survey purpose, if it is open then it is called as open traverse.

GPS –Global position system is a modern technique used for survey.GIS is also used for the weather report and other applications.

 In the rolling terrain the interval is considered as 50m and in hilly terrain is taken as 30m.

The first step in preliminary survey is to establish primary traverse followed by survey and detailed project report.

 The HFL is the height till which water raised during recent floods, to avoid the flooding of roads they are always kept above HFL.

The key map shows the proposed site and important places, the key map should not exceed 22*20cm in size.