The document discusses the process and principles of setting out construction projects. It aims to understand the roles of personnel involved, establish horizontal and vertical control, and accurately transfer design plans onto the construction site. Setting out involves using surveying techniques to physically mark design points and ensure all elements are the correct size, position, and level. It requires establishing control grids and points, and using tools like theodolites, tapes, and total stations to lay out foundations, structures, and subsequent construction stages to the specifications. Careful planning, quality checks, and clear communication are emphasized to accurately set out projects and avoid costly mistakes during construction.

1. SETTING OUT
CONSTRUCTION ENGINEERING CE-375
SE SHAHID HUSSAIN

2. Aims - Setting out
• Understand roles of various personnel involved in setting out
• Understand the aims of setting out
• Acquaint with good working practices
• Horizontal/Vertical control requirements of setting out
• Methods of setting out design points on site
• Stages of setting out
• Quality control measures/checks

3. Setting out
• It is simply the physical transfer of the building drawing plans
onto the ground.
• It is one application of surveying , rather the reverse of
surveying.
• Most of the techniques and equipment used in surveying are
also used in setting out.
• Mistakes in setting out can be costly.
• Setting out is the responsibility of the contractor.

4. Principles of Setting Out
The various elements of the scheme must be correct in all three dimensions,
that is each must be its correct size, in its correct plan position and correct
reduced level.
• Horizontal control techniques
• The Easting and Northing coordinates are located by fixing at least two
or three of them so that the work can be independently checked.
• The design points must be set out to the accuracy stated in the
specifications.
• Vertical control techniques
• In order that design points on the works can be positioned at their
correct levels, vertical control points of known elevation relative to
some specified vertical datum are established.

5. Control Points
• Principle of working from the whole to
the part using two different levels of
control is used.
• On some schemes the same control
points that were used in the production
of the site plan prior to design work are
used. These must be re-measured
before setting out as positions may
have changed.
• Horizontal control points should be
located as near as possible to the site in
open positions for ease of working, but
well away from the construction area
and traffic routes to avoid them being
disturbed.

6. Control Points
• Construction and protection of control points is very
important.
• Wooden pegs are often used for non-permanent stations.
• For permanent control points it is recommended that they
be constructed with concrete.

7. Reference Grids
A control grid enables points to be set over a large
area. Several different grids can be used in setting out
• Survey grid is drawn on the survey plan from the
original traverse. Grid points have known Eastings
and Northings related either to some arbitrary origin
or to the national grid.
• Site grid: Used by designer & related in some way to
survey.
• Structural grid is established around a particular
building or structure which contains much detail
such as columns, which cannot be set out with
sufficient accuracy from the site grid.
• Secondary grid is established inside the structure
from the structural grid when it is no longer possible
to use the structural grid to establish internal
features of the building – as the vision becomes
obscured.

8. Tools for Setting out

9. Setting out Techniques
• Setting out using a theodolite and tape

10. Setting out by Total Station
• Total station is levelled and centred over a control point. Orient
it horizontally and vertically to the site coordinate system.
• For horizontal orientation, the coordinates of the control point
at which the instrument is set up are entered into the total
station then it automatically computes the bearing from the
total station to other points.
• For vertical orientation, the height of collimation of the total
station has to be determined. If the height of the control point
at which the total station is known, this is entered into the
instrument .
• Once the total station has been orientated it can be used for
setting out horizontal and vertical positions either using the
coordinates of the points to be set out directly or using bearing
and distance values calculated from these coordinates.

11. Stages in setting out
• First stage setting out.
• In practice, first stage setting out involves the use of
many of the horizontal and vertical control methods
and positioning techniques.
• To locate the boundaries of the works on ground and
define major elements.
• Second stage setting out.
• Second stage setting out continues on from the first
stage, beginning at the ground floor slab, road sub-
base level etc.
• Up to this point, all the control will be outside the
main construction, e.g, the pegs defining building
corners, centre lines and so on will have been
knocked out during the earthmoving work and only
the original control will be undisturbed.

16. Setting out

26. Misc Points/Tips
• Get the overall site handed over to you by the client through competent
authorities as per the site plan.
• Check/Study the block plan and site layout plan carefully before starting
setting out. Specially check for the existing features and their consistency
with the site plan and proposed buildings.
• Walk over the site and check that there is no evidence of hidden features
that might affect the setting-out or construction of the works.
• Don’t trust the existing neighbouring boundary as they may not be
legally/correctly installed. Making them reference will result in faults in
your plans.
• Install permanent bench marks and reference points.
• Clear/Strip the site, remove the trees & their roots, all vegetation and
bushes before setting out as per the contract agreement.

27. Misc Points/Tips
• Check the dimensions of the rooms, walls and building area and compare the
proposed plans with the area available. Do not scale the drawings. Use the
dimensions and check that intermediate dimensions agree with overall
dimensions.
• Calculate the centre lines of the walls if not already shown in drawings.
• Find out the diagonal of the rooms and the building using the centre lines.
Note that Rectangles have same diagonals.
• During excavation, the centre points marked during initial setting may get
removed. Therefore the centre lines are extended and the centre points are
marked about 2m away from the outer edge of excavation.
• Centre lines should be shown clearly by stretched thread or rope.

28. Misc Points/Tip
• If the plan is much too complicated and follows zigzag pattern, then
the centre pegs are kept at suitable positions according to site
conditions.
• One of the classic mistakes is getting the floor plan out of square.
• Adjust the errors internally if exteriors areas are fixed.
• Offset the line around the obstacle.
• Check levels by ‘eyeing-in’ on known levels.
• It is good practice to only square one corner and set out subsequent
walls by parallel measurements. This will ensure that if a true
rectangle is not set out (and all measurements are still accurate), the
shape will be a parallelogram (rhombus) and will therefore be easy to
correct.
• Use spirit level frequently.

29. Misc Points/Tip
• Report any discrepancies found in drawings and/or at site in writing and
keep a copy.
• Confirm any oral instructions in writing.
• Set up a system of recording and communicating information.
• Set up the CAD system to ease in making copies of drawings, getting minor
details/blowups and working out details/angles/radius offsets etc
• Apply manual/traditional checks for work executed using modern survey
equipments.
• Never conceal your errors or your doubts.
• Check pegs from offsets, do not assume they are correct or remain
undisturbed.

32. Any Questions ????