Land Survey

Welcome to all reader's now we are starting first topic of our Quantity Survey and Estimation.



1. Name of Work and Description

Land Survey is the 1st process of our project, this activity will be executed after land purchase, or any government future plan are reviewed. with the help of land survey all plot levels, contour line, topographical plan will prepare. with the help of Land survey all points are clearly understand by architecture or any authorities because land survey sheet clearly mention exact points of Road, River, Nallah, Well, Highlighted area and deep area. it can be show's trees, light pole, drainage line, man made structures, buildings, developments, etc. any survey is valid only for 10 year's.

There are different types of Land Survey.
1. ALTA/ ACSM Survey
ALTA: American Land Title Association
ACSM: American Congress on Surveying and Mapping
2. Boundary Survey
3. Location Survey
4. Site Planning Survey
5. Sub Division Survey
6. Topographic Survey


2. IS Code No.

Land Survey is worked under survey of india.

3. Which Drawing need to read.

Following drawings are prepared after land survey.
1. Topographic Survey Drawing
2. Plain Table Survey Drawing
3. Contour Drawing
4. Reduced Level (RL) Drawing
5. RL Section Drawing



4. Location of Work

Land survey is generally done on open ground but in some cases it will be done in different locations like From sea underwater survey, basement of building, Metro or road tunnel, in vally for bridge construction, on agricultural land to mark boundaries, etc.


5. Standard Procedure of Work (Step by Step)

There are many types of Survey here we will read on important and daily used survey types and it's procedures.

1. Plain Table Survey:

1. Arrange the table Equipment on tripod. fix the Drawing sheet on table.
2. After fixing the Drawing with the help of clips, fix the plum bob at the center of table.
3. Put the cross hairs and compass on sheet.take the scale in one hand.
4. Mark 1 point on sheet where plum bob is spotted.
5. Now you can start the survey, 1st take the measurements of 0 point to building corner or Compound wall corner. after focus by crosshair on corner of building or corner of compound wall  With the help of scale draw the line and convert this line in 1:10 scale i.e. if distance is 100 meter you need to draw the line 10 cm. mention scale on right side bottom of drawing with date.
6. Focus on all visible and draw the line as per previous procedure.
7. close the survey after completed all drawing.

2. Dumpy Level/ Auto Level Survey

1. Set the Dumpy /Auto Level on Tripod
2. Level it, measure the height of Dumpy/Auto Level with the help of tape.
3.With the Help of Staff take the reading at 1st point which RL is known to you. which is Back sight.
4. Then take all the staff reading and note down as per given format.
5. If you want to shift the Dumpy/Auto Level Please take last reading again.
6. After taking all points reading please close the survey after taking first point reading.
7. Dumpy/Auto level work in X Y axis, ie only Horizontal axis.

3. Total Station/Theodolite.

Both are different but result is same
1. Fix the Total station on tripod in known point whose coordinate are already known.
2. Level it horizontally and Vertically. (This will take little bit time)
3. input all the points coordinate in the Total Station
4. now with the help of prism mark the exact point of your co ordinate.
5. Total Station/Theodolite is work in X Y and Z axis, i.e
Horizontal and vertical axis.



6. Checkpoints.

1. Plain Table Survey
Cross check the Scale and Plot measurements.
Cross check area of plot

2. Dumpy/Auto Level Survey
Cross Check RL and Height of Instrument HI and cross check with tape.
After close the survey Difference in RL must but less than 5mm

3. Total Station/Theodolite
Check Coordinate values
Cross check distance between 2 points by tape.
Cross check Diagonal of any 2 perpendicular lines.



7. Equipments and Machinery Required.

With the help of advanced technology there are lot of tools and Machines are available to prepare land survey.
Following are some equipment which are use in land survey
1. Cosmolabe
2. Dioptra
3. Theodolite (18 types)
4. Tachymeter
5. Graphometer
6. Universal Instruments
7. Transit
8. Total Station
9. Alidade
10. Alidade Table
11. Plane Table
12. Dumpy Level
13. Measurement Tape
14. Pole
15. Surveyor Chain
16. Engineer Chain
17. Level Staff
18. Ramsden Surveying Instruments
19. Ranging Rod
20. Prism
21. Tripod
22. Prismatic Compass





8. Measurement and Quantity Survey.

Dumpy/Auto Level Measurements Procedure
Please prepare table as per given format. and enter the reading one by one.
1. First reading is always Back Sight(BS).
2. Last reading is always Foresight(FS)
3. other all reading are always Intermediate Sight(IS)
4. RL : Reduced Level and TBM: Total Bench Mark is Given or need to assume as 100.00
5. HI : Height of Instrument. RL+BS= HI
6. Next point RL = HI- IS
7. Last Point RL = HI - RL
8. Please take all Reading on 10mx10m Interval after that we can create contour drawing.
9. Connect the all points on a same RL is called contour line, which is showing ups and downs in ground.

Plain Table Survey

1. After creating a drawing as per above procedure.
2. Make geometric shapes on drawing by pencil.
3. Mark those area 1, 2, 3 , 4 , 5 etc.
4. Write the value as per area. like if triangular shape write 1/2×base x height, etc.
5. Calculate the area as per all shape, use right formulas for shape.
6. After calculate all area add it. and multiply it by 100 times or what ever you have assumed the scale while survey, for that you can check the drawing.
7. This is your plot area.

Total station survey

1. This is automatically check all the point and export it in Autocad software.
2. As we discussed is Contour survey,
3. On this principal Total station is working and giving you directly output of drawing of given points as well as contour line.
4. This is big discussion point we will discuss on it after this course. if any one want please drop us Mail.



9. Check list:

Dumpy Level/Theodolite/Total Station/Auto Level.
1. Set Tripod at on ground, where you can cover by maximum area visibility.
2. Connect dumpy level/Auto level to tripod, fix and tight it properly.
3. Now adjust tripod on assumed point, and keep it in level.
4. Level the instrument with the help of bottom screw, level is visible at spirit level bar.
5. Turn 90° of instruments with last adjusted level, one one screw adjust the level.
6. After reading All RL calculation should be cross check.
7. Before prepare drawing convert it in proper scale.
8. When draw the line on paper please keep exact measurements on scale ratio.
9. Use good and Sharp pencil while doing plain table survey, which is helpful for Exact measurements.
10. While plain table survey, Fix drawing on exact center, and don't remove it until survey is complete.
11. While total station survey keep one battery in spare, there are main issue of battery discharge while big plot survey.
12.Calibration Report of Total station/Dumpy Level/ Auto level/Theodolite, etc.



10. On site Experience:

Readers Experience : In Mumbai while surveying a plot one major problems we faced regarding the theodolite,Ground level different is more than 6 meter so we can't use line as well as diagonal by tape, so that time we used theodolite, but due to some calibration issues in theodolite, All point are given us by us is Wrong and shifted by 75mm. all columns are need to do jacketing due to that issue, so guys please update your instruments on time and do calibration from good agency periodically. Thank you.
Mr. Sunil (Surveyor)

Please share your experience.

For More details of maintain the Reading record watch Video.






Team
CBEC India