Column Column position positionss are identi identifie fied d by using using grid grid co- ordinates ordinates as in column column lay out drawings. Distances between co- ordinates are also given in drawings. New grid lines can be obtained by using transferred baselines from the lower floor (baseline may be some sort of a off line) In setting out, we normally provide off lines to the column. s we !now the column si"e we can calculate the distance to the off line from the baseline #rid
% #rid &
$ase 'ine ++mm off to grid D
$ase 'ine ++mm off to #rid
100mm of line to the column
#rid Column position
Setting out on the slab
fter concerting the first floor slab, setting out should be carried out to locate the column centers as previously done in the ground floor. In our site we used the plumbing system for this purpose. irst of all we plumb the ground floor column centers to the first floor slab using plum bob. It was mar!ed on the edge of the slab. 'i!e this all the edge column centers were mar!ed on the edge of the first floor slab. hen string lines were pulled between the mar!ed centerlines at the edge of the first floor slab. ith the help of these string lines we can easily mar! the centerlines of the columns at the middle of the first floor slab. hen there is a difficulty to mar! the centerlines we have to mar! an off line ++mm away from the centerline. fter mar!ing this line at the middle of the slab we can easily mar! the centerline of the middle columns. Setting out Beams
his level was set out on the column because it was easy to place beam bottoms reference to that level mar!ed. his is the &+++mm levels, above the structural floor level.
'eveling instrument was set out on the ground and the /taff was held vertically on the benchmar!, represents the structural floor level.
/taff reading was ta!en.
Calculate the reading, which should be observed on the tape.
ape was held vertically along the column bo0 and move up or down according to instructions given by surveyor helper the "ero point of the tape gives &m levels.
Level marked in column
Problems Encountered •
In setting out footings Distances cannot be measures along the ground. $ecause it was not a well leveled surface. here were slopes in the ground floor. imber pegs roughly to a one same level by using concretes.
hen measuring hori"ontal distances the tape can be sag. o overcome this problem, the tape should be pulled and pegs were embedded at closer intervals.
1n the slab some time water was there. /o, water was removed by wiper.