LESSON NOTE ON SETTING OUT WORKS - FOUNDATION MARKING

SETTING OUT WORKS - FOUNDATION MARKING

AIM

To set out the foundation marking for the proposed construction of building.

APPARATUS USED

1.Theodolite, 2. Chain (or) Tape 3.Ranging rods, 3. Pegs or Arrows, 4. String.

GENERAL

The operation of the marking on the site the centr e lines of the foundation of a building is called

setting out. Setting out of a foundation is the first step in the construction of any structure.

PROCEDURE

1.

A centre line sketch of the building is prepared. (The centres of cross walls are also to be indicated.)

2.

The base line is set out with reference to given reference points.

3.

The ends of the centre line of the walls, points A and B from the base line are marked.

4.

As the end marks A,B,C,etc. are disturbed during excavation, stakes are fixed at L,M,N etc., a little

away (about 2 to 3 m) for end mark and tied accur ately using a string.

5.

The centre line for all other walls AD,BC,etc  are marked by dropping perpendicular. For small

buildings the perpendiculars may be set out by using a chain or a tape by ‘3-4-5’ method. For an

important and big building when sides are long a Theodolite may be employed to accurately set out the

perpendiculars and to range the lines.

6.

For every wall, the pegs are driven a little away for marking the end and tied accurately using a string.

7.

Diagonals ar e measured and checked with their corresponding calculated lengths.

8.

Width of foundation from the centerline are marked and the corners 1,2,3,4,5 etc., are fix up. Pegs are

driven at these corners. The cord is stretched and lime is spread along the chords.

RESULT:

Thus the trench plan being marked on the ground, and excavation may be started.