Permanent benchmark
These are reference
points
established by Geological Survey
of India, which
represent
the actual
elevation of the specific point with respect to mean sea level (MSL).
Temporary benchmark (TBM)
These are temporary
reference points established on the site, and are used as the reference to which, all the other levels at the site are taken.
Reduced level
(RL)
The reduced level of a place is the numerical representation of the altitude of that place with respect to a benchmark.
Base line
This is the reference line established along one direction
in a site, using
which the rest of the grid lines
are fixed and the marking pillars are established, as per the setting out drawing.
Setbacks:
The minimum
distance between the line of the building
and the outside face of the compound
wall, or, the
distance between
2 building lines,
is called as setbacks.
PCC
Plain Cement Concrete
