Engineering Surveying Levelling By Mohd Arif Sulaiman Faculty of Civil Engineering & Earth Resources mdarif@ump.edu Introduction To Survey Engineering, by Mohd Arif

Chapter Description Expected Outcomes Able to explain the theory of differential levelling Able to explain the techniques of levelling Able to calculate the reduce level in profile and cross section levelling. References Barry F. Kavanagh, "Surveying with Construction Application", 0-13- 048215-3 Pearson, Prentice Halll, 2004. Bannister, Raymond, Baker,"Surveying",0-582-30249-8, Prentice Hall 1998. William Irvine, "Surveying for Construction", 4th  Ed.,0-07-707998- 1, McGraw-Hill,1998.

WHAT IS LEVELLING?? is the procedure used when one is determining differences in elevation between points that are remote from each other. The process of measuring the difference in elevation between two or more points. is the operation required in the determination or, more strictly, the comparison, of heights of points on the surface of the earth.

TERMINOLOGY BACK SIGHT – The first reading taken by observer after setting out the instrument FORE SIGHT – the last reading taken by observer before move the instrument INTERMEDIATE SIGHT – the reading taken between back and foreword reading

BS FS BS IS FS F E B C A D

METHOD USED TO MEASURED ELEVATION Taping Method Barometric Leveling Trigonometric Tacheometry Leveling Differential Leveling GPS

Principle

Actual levelling

Levelling Instrument

Setting up the instrument Temporary Permanent (Two-peg test) C A B

Differential Leveling Method or Procedure leveling between two points flying leveling (for vertical control survey) series leveling (for profile/longitidul and cross- section leveling) inverted staff reading for determine the reduced levels of point above the height of the instrument (the soffit level of bridge or headroom bridge) Reciprocal leveling

leveling between two points

flying leveling (for vertical control survey)

series leveling (for profile/longitidunal and cross-section leveling)

inverted staff reading

Method of booking Rise and fall HOC

Method of booking

– Rise and fall method BS IS FS RISE FALL REDUCE LEVEL REMARKS 2.543 13.877 TBM 2.211 0.332 14.209 A 2.087 0.124 14.333 B 2.976 1.988 0.099 14.432 C 2.143 2.562 0.414 14.846 D 4.223 2.888 0.745 14.101 E 4.230 0.007 14.094 F 5.332 1.102 12.992 G 0.922 4.410 17.402 H 11.885 8.360 5.379 1.854 - 8.360 -1.854 -13.877 3.525

HOC method BS IS FS HOC REDUCE LEVEL REMARKS 2.543 16.420 13.877 TBM 2.211 14.209 A 2.087 14.333 B 2.976 1.988 17.408 14.432 C 2.143 2.562 16.989 14.846 D 4.223 2.888 18.324 14.101 E 4.230 14.094 F 5.332 12.992 G 0.922 17.402 H 11.885 8.360 - 8.360 -13.877 3.525

Author Information Dr Idris bin Ali Dr Cheng Hock Tian