1. Faculty of Applied Engineering and Urban Planning Civil Engineering Department First Semester 2010/2011 Surveying Chain Surveying Part I Lecture 4 - Week 3

2. Previous Contents Errors in Surveying Sources of Errors Types of Errors Blunders Systematic Errors Random Errors

3. Contents Common Methods for Measuring Distances Equipment Used in Chain Surveying Processes in Chain Surveying

4. Common Methods for Measuring Distances Pacing Taping Tachometry EDM (Electronic Distance Measurement)

5. TypeRelative PrecisionUse Pacing1/50 to 1/200Reconnaissance Taping1/1,000 to 1/5,000Land surveys EDM±0.04 to 1/300,000All types of surveying Measuring Methods

6. Equipment Used in Chain Surveying Measurement of Lines Chain Tapes Invar Tapes Making Right Angles Optical Prism Cross Staff

7. Equipment Used in Chain Surveying Others Ranging Rods Arrows Pegs Plumb bobs Clinometers Abney Level

8. 1- Equipments used for the measurements of lines : A- The chain B- Tapes: synthetic, glass fiber, coated steel or plain steel of lengths: 10m, 20m, 30m, 50m., tapes are more accurate than chain. C- Invar Tapes: accurate tape made of steel (65%) & Nickel (35%) but they are very expensive. Equipment Used in Chain Surveying

9. 2- Equipments used for making right angles : A- The cross staff: B- Site square: consists of two telescopes, their lines of sight at 90º. C- The optical square : There are two types: mirrors & prism

10. 3- Other equipments: a- Ranging Rods: 2m, 2.5m, 3m long & painted red and white each 0.5m with a pointed steel shoe. b- Arrows: 40cm long & 3- 4 mm in diameter. c- Pegs: wooden (square or circular cross-section) & steel Equipment Used in Chain Surveying

12. 12 Equipment Used in Chain Surveying d- Plumb Bob: a metallic cone object used to erect vertical lines. e- Clinometer & Abney level: used to measure the inclination angle of slope lines.

13. 13 Measuring wheels Tapes in lengths up to 100 ft Some Taping Instruments

14. Two Measurement are performed ranging and measurement of lines setting out of right angles Processes in Chain Surveying Take the following points in mind when doing measurements: the measurement should be in a straight line the tape should be reasonably pulled systematic way should be followed

15. Processes in Chain Surveying Ranging and Measurement of Lines Level Ground Uniformly Sloping Ground Uneven Ground

16. Level Ground ABA1A1 A2A2 A3A3 A4A4 Rod

17. Uniformly Sloping Ground

18. Uneven Ground

20. Questions?!