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LEVELING SURVEY

LEVELING SURVEY. CONCEPTUALIZING SURVEYING AND LEVELING. QUESTION NUMBER 2. Illustrate the leveling process D escribe the principle of leveling and its applications in survey process. CONCEPTUALIZING SURVEYING.

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LEVELING SURVEY

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  1. LEVELING SURVEY CONCEPTUALIZING SURVEYING AND LEVELING

  2. QUESTION NUMBER 2 • Illustrate the leveling process • Describe the principle of leveling and its applications in survey process

  3. CONCEPTUALIZING SURVEYING • Surveying is art of determining the relative position of different objects on the surface of the earth by measuring the horizontal distance between them, and by preparing a map to any suitable scale. Thus, in this discipline linear and angular measurements are taken either in the horizontally or vertically plane. In such that, surveying has four types which are chain survey, prismatic compass survey, plane table survey, and leveling survey.

  4. CONCEPTUALIZING LEVELING • Meaning of leveling according to Basak N.N (1994), Leveling is the art of determining the relative vertical distance of different points on the earth’s surface • Meaning of leveling according to Niwa (2004), This is branch of surveying the object of which is to find the elevation of given points with surface of the earth. Therefore, in leveling measurement in leveling are taken only in vertical plane respect to or assumed datum and to establish point at a given or assumed datum.

  5. CONCEPTUALIZING LEVELING CONTI’D • Generally leveling refers to the process of determining the height of one level relative to another. • It is used to established the elevation of appoint relative to a datum or to establish a point at a given elevation relative to a datum, or is a branch of surveying in civil engineering to measure level of different point with respect to a fixed point such as elevation of building height on a point from ground.

  6. TYPES OF LEVELING • Leveling As a method of surveying, it has been divided into four types according to Niwa (2004) where there are differences between those types. Those four types of leveling are follows; • Direct leveling, is the most common used method of leveling in this method measurement are observed direct from leveling instrument. Based on the observation point and instrument, direct leveling is divided into various types that are explained below.

  7. TYPES OF DIRECT LEVELING • Simple leveling. • Is a simple and a basic form of leveling in which the leveling instruments are placed between the points which elevation is to be found. It is performed only when the point are nearly to each other without any obstacle. • It can be well illustrated through the diagram below;

  8. SIMPLE LEVELING DIAGRAM

  9. TYPES OF DIRECT LEVELING (b) Differential leveling • Is the term applied to any method of measuring directly with graduated staff the difference in elevation between two or more points. It performed when the distance between two points is more. In this process number of inter stations are located and instruments are shifted to each station and observed the elevation of their station points. Finally difference between original two points is determined.

  10. DIFFERENTIAL LEVELING DIAGRAM

  11. TYPES OF DIRECT LEVELING ( c) Precise leveling  Is similar to differential leveling but in this case higher precise is wanted. So serious observation procedures are performed. (d)Profile leveling Is generally adopted to find elevation of points along a line such as of roads, railways or river.

  12. TYPES OF LEVELING 2. Trigonometric leveling It is the process of leveling in which the elevation of points or the difference between points is measured from observed horizontal distance and vertical angles in the field. In this method trigonometric relations are used to find the elevation of a point from angle and horizontal distance. it is also called as indirect leveling. •  it has been more illustrated in the diagram below;

  13. TRIGONOMETRIC LEVELING DIAGRAM

  14. TYPES OF LEVELING 3. Barometric leveling Barometer is an instrument used to measure atmosphere at any altitude. So in this method of leveling, the atmospheric pressure at two different points are observed. Based on which the vertical difference between two points is determined, it is a rough estimation and used rarely.

  15. TYPES OF LEVELING 4. Stadia Leveling it is a modified form of trigonometric levelling in which tacheometer principle is used to determine the elevation of point .in this case the line of sight is inclined from the horizontal. It is more accrue suitable for surveying in hilly terrains.

  16. EQUIPMENTS USED IN LEVELING • The following are the equipments that are used in leveling process; • Levelling staff or the levelling road, levelling staff is a suitably graduate staff for reading vertical height,so this is a graduate wooden staff for reading vertical height • Telescope is an instrument that is used for sighting the levelling staff and obtain angles • Tripod stand- it is used to fix the telescope

  17. EQUIPMENTS CONTI’D • Level, the level is an instrument used to accurately determine the different in elevation between two points on the earth surface. Example water level and surveyors level. It give a truly horizontal line.  

  18. PRINCIPLE OF LEVELING & APPLICATION Principle of levelling • It is applied in survey to measure the two points with different elevation on the earth surface. So due to this principle of levelling can help the man to measure these point like point A has a higher elevation than point B you can measure those elevations by using simple leveling to create some level of this points. According to Yonge Deng (1968), when level is placed between point A and point B horizontal sight line respectively

  19. PRINCIPLE AND APPLICATION CONTI’D intersected leveling staff of leveling point A and point B. • For example, in the figure below if we select horizontal and the level surface through point A to analyze, suppose the horizontal surface intersect line BB at BO, and suppose the level surface intersect the line BB+ at B+ the based on AA.

  20. DIAGRAM

  21. CONCLUSION • Generally, leveling has importance in the field work including, it helps the surveyor or cartographer to make contour maps of the land sea surface. This is because it determines the benchmark, also it help in construction of routes of transport like roads and railways also helps constructors to lay a level ground on which they can elect a level building, also helps pipes transport engineers to ensure appropriate slope of the land that will allow smooth moment of the liquid in transit. For example, water and liquid.

  22. REFERENCES Basak N.N (1994) Surveying and Leveling. Tata McGraw-Hill. New Delhi, India. Bhavikatti S.S (2010) Surveying and Leveling, Volume 1, I.K. International Pvt Ltd. http://www.chem.tottori-u.jp/niwa/tpd/tpd-index.htm/google

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