Question

Briefly describe the use of profile boards in setting out works in a construction site. Use clear sketches for explanations. b) a) Describe the setting out method for a rectangular structure using a theodolite and tape. c) What is meant by a slope stake? Briefly describe how the position of a slope stake can be established for a road embankment by using a tape and a levelling instrument. d) Calculate the data that are required to establish a batter rail for use with a 1.2 m long traveller, which will define an embankment that would slope upwards at 1 in 2 from a formation level of 55.475 m.

Answer 1

Extented site Profile Board External Boundaries Peg Site

While doing the setting out work we mark the points with the pegs after ranging the point This can be seen in the case of marking the corners and external boundary line of the site But, sometimes there are situations when we have to remove the pegs out of the point. This situaton may appear when we have to do the excavation activity at that point or through that point. Sometimes the machinery has to move inside or outside the site area Profile Board |so these pegs are to be removed in these cases. This removing of pegs may lead to the improper marking of the points and levels.Thus, to counter this problem the profile boards are used. The purpose of these profile board is to ensure a permanent marking of the point and levels during the setting out work and also during the construction. These profile boards are placed

at certain distance away from the original point which may affect the markings.The point is marked as at a location which is secured from any disturbances by extending the line of sight such that the top edge of the peg or ranging rod coincides with the top edge of the profile board. This thereby helps in maintaining the level mark during the setting out of the site.