Unit-1 Overview and classification of survey:
Includes linear angular measurements :
• We can locate boundaries of plot Dfow MAP - MAP, PLAN, GPS, GIS (Satellite)
Civil engineer can prepare a layout plan in which planning of any building project work can easily be done
Purpose or object of surveying:
1) before starting any construction work or any structure or project; the surveying of land the ground is done
2) Surveying is the method of taking the measurement of the relative positions of the points on above, or beneath the earth surface
3) In short surveying deals with linear and angular measurement in horizontal plane and in vertical plane
Types of surveying
1) Plane surveying
2) Geodetic Surveying
1) Plane surveying:
In this type of surveying the mean surface of the earth is considered as a plane and the spheroidal shape is neglected
2) Geodetic Surveying:
I this type of surveying the shape of earth is taken into account all lines lying in the surface are curved lines
Secondary classification of surveying
A) Based on nature of field of survey
1) Land Surveying
2) Marine Surveying
3) Astronomical Surveying
B) Based on object of survey
C) Based on instruments used
A) Based on nature of field survey :
1) Land Surveying-
a) Topographical surveys:-
This is made to determine the Natural features of country such as rivers, streams lakes etc and Artificial features as roads, railways, canals, towns and villages
b) Cadstral surveys:-
Cadstral surveys are made for fixing of property lines, the calculation of land area or the transfer of land property from one owner to another
c) City surveying:-
City surveying are made in connection with construction of streets, water supply system etc.
2) Marine survey:
Marine survey or hydrographic survey deals with bodies of water for purpose of navigation water supply etc.
3) Astronomical Survey:
It is used to determine absolute location of any point or the absolute location and direction of any line on the surface of the earth.
B) Classification based on object of survey :
1) Engineering survey-
Used to determine or to collect the data for designing the various engineering works such as roads, railways, reservoirs, dams etc.
2) Military survey-
Carried out by MSD (Military Survey Department)
MSD provides all kinds of Spatial Data and geographic information
3) Mine survey:
Carried out to determine the relation positions and elevation of mines, shafts, adits, bore holes etc (For underground works)
4) Geological survey:
Carried out to obtain information about different states of Earths surface
5) Archeological survey:
These are done to unearth relics of antiquity
C) Classification based on instrument used :
1) Chain surveying
2) Theodolite surveying
3) Traverse surveying
4) Triangulation surveying
5) Tacheomatric surveying
6) Plane table survey
7) Photographic survey
8) Ariel survey
Syllabus topics
1) Layout survey:
•In layout survey the dimensions from Layout plans are transferred to the ground
•Carried out to establish location of structure objects or property corners according to proposed design plans
•intersecting the constitution plans and marking the location of proposed new project
2) Control Survey:
It consists of establishing the horizontal and vertical positions of widely spaced control points using the principle of Geodetic survey
3) Topographic survey:
In this survey horizontal and vertical location of the object or the features on the surface of the earth are determined
4) Route survey:
It is the survey which carried out along a narrow strip of Territory for location and construction communication lines like roads, highways, railways, canals, sewer line etc.
Route survey can be carried out in following stages:
1) Reconnaissance Survey
2) Preliminary Survey
3) Location Survey
4) Construction Survey
• Principles of Surveying
1) To work from whole to port
- It is essential to establish control points with High precision first and then establish Minor control points
- Any inner details can further be located within the minor control points
- To work from whole to part means that entire area or very large area from the area to be surveyed is first consider and then it's smallest parts are considered
- It can be used to prevent thr accumulation of errors
2) To fix or to locate a new point or station by atleast two independent measurement
- The relative position of the points to be surveyed should be located by measurement from atleast two points of reference the position of which have already been fixed
- Position of two points from the two known points can be fixed or located by taking
a) Angular measurement
b) Both linear and angular measurement
•Plan
- A plan graphically represent the features on or near the Earth's surface as projected on a horizontal plane
- a plan is drawn on a relative large scale
•Map
- If the scale of the graphical projection on a horizontal plane is small the plan is termed as Map
Representative fraction (R.F.)
- It is the ratio of the distance on the map to the corresponding distance on ground
R.F. = Distance on plan or map/Corresponding distance on ground
Example:
If plain scale is 1cm = 5cm
1cm - on plan or map
5cm - on ground
∴ R.F. 1/5 = 1cm/5×100cm = 1/500
Example:
If plain scale is 1cm = 5cm
1cm - on plan or map
5cm - on ground
∴ R.F. = 1:500
Note: 1:500 means we need to reduce both numerator and denominator to same unit
- larger the denominator smaller is the scale of map
Diagonal scale :
With the help of diagonal scale three dimensions like metres, decimeters and centimetres or units tenths and hundreths can be measured
- Based on Principle of similar triangle
Engineer scale:
Distance ln plan and distance on ground mentioned numerically
e.g. 1cm = 10cm
