Leveling ft. PPT Surveying BSABE 2

• - the process of directly or indirectly measuring vertical distances to determine the elevation of points or their differences in elevation

• - it is necessary to measure accurately differences in elevation and/or determine the elevation of points at measured intervals along a fixed line

• Level surface

• Elevation

• Leveling

is an imaginary surface of the sea which is midway between high and low tides. it is taken as the reference surface to which most ground elevations are referred.

• Elevation

• Datum

• Mean sea level

vertical distance above or below mean sea level or any other selected datum

• Datum

• Elevation

• Mean sea level

is any convenient level surface coincident or parallel with mean sea level to which elevations of a particular area are referred

• Datum

• Elevation

• Mean sea level

difference in elevation between two points is the vertical distance between the two level surfaces in which the points lie

• Datum

• Difference in elevation

• Elevation

• Elevation differences

is a curved surface which is any point perpendicular to the direction of gravity or the plumb line

• Level surface

• Level line

• Horizontal surface

• vertical surface

is a curved line in a level surface all points of which are normal to the direction of gravity and equidistant from the center of the earth

• level surface

• level line

• horizontal surface

• vertical line

is a plane that is tangent to a level surface at a particular point

• level surface

• level line

• horizontal surface

• vertical line

a vertical line at any point is a line parallel to the direction of gravity

• level surface

• level line

• horizontal surface

• vertical line

spirit level is used to fix the direction of the horizontal line of sight. It is commonly employed method of determining the elevation of points some distance apart by series of set ups of a leveling instrument along a selected route.

• Direct or spirit leveling

• Reciprocal Leveling

• Barometric leveling

• Profile leveling