29-10-2014, 09:47 PM
Anna University , Chennai
Department of B.E-Civil Engineering
Fourth Semester
CE2254 Surveying-II
(Regulation 2008)
Lecture Notes of Unit 2, 3 , 4 and 5
Horizontal control & its methods:
The horizontal control consists of reference marks of known plan position, from which salient points of designed structures may be set out. For large structures primary and secondary control points are used. The primary control points are triangulation stations. The secondary control points are reference to the primary control stations.
Reference Grid
Reference grids are used for accurate setting out of works of large magnitude.
The following types of reference grids are used:
1. Survey Grid
2. Site Grid
3. Structural Grid
4. Secondary Grid
Attachment : [attachment=17907]