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SETTING OUT WORKS – FOUNDATION MARKING
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AIM
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To set out the foundation marking for the proposed construction of building.
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APPARATUS USED
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1.Theodolite, 2. Chain (or) Tape 3.Ranging rods, 3. Pegs or Arrows, 4. String.
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GENERAL
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The operation of the marking on the site the centr e lines of the foundation of a building is called
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setting out. Setting out of a foundation is the first step in the construction of any structure.
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PROCEDURE
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1.
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A centre line sketch of the building is prepared. (The centres of cross walls are also to be indicated.)
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2.
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The base line is set out with reference to given reference points.
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3.
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The ends of the centre line of the walls, points A and B from the base line are marked.
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4.
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As the end marks A,B,C,etc. are disturbed during excavation, stakes are fixed at L,M,N etc., a little
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away (about 2 to 3 m) for end mark and tied accur ately using a string.
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5.
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The centre line for all other walls AD,BC,etc are marked by dropping perpendicular. For small
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buildings the perpendiculars may be set out by using a chain or a tape by ‘3-4-5’ method. For an
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important and big building when sides are long a Theodolite may be employed to accurately set out the
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perpendiculars and to range the lines.
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6.
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For every wall, the pegs are driven a little away for marking the end and tied accurately using a string.
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7.
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Diagonals ar e measured and checked with their corresponding calculated lengths.
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8.
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Width of foundation from the centerline are marked and the corners 1,2,3,4,5 etc., are fix up. Pegs are
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driven at these corners. The cord is stretched and lime is spread along the chords.
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RESULT:
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Thus the trench plan being marked on the ground, and excavation may be started.
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