Report on Levelling
TABLE CONTENT NO | CONTENTS | PAGES | 1 | Introduction | 2-6 | 2 | Objectives | 6 | 3 | List Of Devices | 6 | 4 | Procedure | 6-7 | 5 | Product and Result | 8-10 | 6 | Analysis | 11-12 | 7 | Conclusion | 13 |
1.0 INTRODUCTION
Linear surveying such as traverse survey, representing the earth’s features in two dimensions on plan. To be practical value, however, the third dimension, namely the height of the feature, must be shown by some means on the plan.
The heights (Reduced level or elevation) of the points are referred to some horizontal plane of reference called the datum (universally employed Mean sea level). In surveying, these heights are found by levelling.
Levelling is the procedure used when one is determining differences in elevation between points that are remote from each other.
Levelling Terminology:
Elevation (Reduced Level) : the vertical distance from a vertical datum
Vertical datum: any level surface to which elevations are referred (i.e. mean sea level)
Mean Sea Level (MSL) : the average height of the sea’s surface for all stages of the tied over a 19-year period.
Temporary Bench Mark (TBM) : is a semi permanent point of known elevation.
Bench Mark (BM): is a permanent point of known elevation. The elevation determine by JUPEM
Back sight (BS) : is a rod reading taken on a point of known.
Intermediate sight (IS): is a rod reading taken at any other point where the elevation is required.
Foresight (FS): is a rod reading taken on a turning point, bench mark or TBM in order to determine its elevation.
Differential Levelling:
LEARNING OBJECTIVE: Upon completing this section, you should be able to determine elevations in the field to locate points at specified elevations.
The most common procedure for determining elevations in the field, or for locating points at specified elevations, is known as differential levelling. This procedure, as its name implies, is nothing more than finding the vertical difference
1.0 INTRODUCTION
Linear surveying such as traverse survey, representing the earth’s features in two dimensions on plan. To be practical value, however, the third dimension, namely the height of the feature, must be shown by some means on the plan.
The heights (Reduced level or elevation) of the points are referred to some horizontal plane of reference called the datum (universally employed Mean sea level). In surveying, these heights are found by levelling.
Levelling is the procedure used when one is determining differences in elevation between points that are remote from each other.
Levelling Terminology:
Elevation (Reduced Level) : the vertical distance from a vertical datum
Vertical datum: any level surface to which elevations are referred (i.e. mean sea level)
Mean Sea Level (MSL) : the average height of the sea’s surface for all stages of the tied over a 19-year period.
Temporary Bench Mark (TBM) : is a semi permanent point of known elevation.
Bench Mark (BM): is a permanent point of known elevation. The elevation determine by JUPEM
Back sight (BS) : is a rod reading taken on a point of known.
Intermediate sight (IS): is a rod reading taken at any other point where the elevation is required.
Foresight (FS): is a rod reading taken on a turning point, bench mark or TBM in order to determine its elevation.
Differential Levelling:
LEARNING OBJECTIVE: Upon completing this section, you should be able to determine elevations in the field to locate points at specified elevations.
The most common procedure for determining elevations in the field, or for locating points at specified elevations, is known as differential levelling. This procedure, as its name implies, is nothing more than finding the vertical difference