This document discusses different types of foundations used in multi-storey building construction projects. It describes surface excavation to remove vegetation and compressible soils. Shoring and timbering is required for trenches over 2 meters deep. Foundations must not exceed the safe bearing capacity of the soil and include spread, stepped, pad, ring, and raft foundations. Pile foundations transfer load through friction and end bearing, and include driven cast-in-situ concrete piles, bored precast concrete piles, under-reamed piles, and Franki piles. Foundations are chosen based on subsoil conditions and load characteristics.

1. CONSTRUCTION OF
MULTI STOREY
BUILDING

4. EARTHWORK

5. CLASSIFICATION OF SOILS

12. SURFACE EXCAVATION
Surface excavation involves the removal of the exposed layer of the earth surface,
including any vegetation or decaying matter which could make the soil compressible and
therefore unsuitable for bearing structural loads. Hence the depth will be vary from site to
site, usually range of 150-300 mm

13. EXCAVATION IN FOUNDATION
TRENCHES OR DRAINS
(ORDINARY ROCK) Excavation
not exceeding 1.5 m in width or 10
m2 on plan to any depth in
trenches (excluding trenches for
pipes, cables, etc) shall be
described as excavation in trenches
for foundations.

16. SHORING AND TIMBERING 11.1 All trenches
exceeding 2.0 m in depth shall be securely
shored and timbered as determined by the
Engineer-in-charge. The above requirements
do not apply in cases where the sides of the
trenches are sloped to within 1.5 m of the
bottom. The slope that is provided for such
purposes shall be inspected and declared as
stable.

18. FOUNDATION
The general aim of foundation choice and
design is to ensure that the loading
intensity imposed on the soil does not
exceed the safe bearing capacity of the
soil. In addition the materials of
foundation, such as, masonry, concrete, etc,
should not be stressed for more than the
limits specified in appropriate codes
governing the structural design of such
elements. The construction procedures
should enable the aim of design in office to
be realised in the field.

19. SPREAD FOUNDATIONS
In spread foundations transfer of load
is primarily through shear resistance of
the bearing soil and they are normally
laid to a depth of 3 m. Strip
foundations provide continuous and
longitudinal bearing of loads, such as,
wall elements, beams and the like. The
soil bearing capacity is limited for
choice of such foundation. These
foundations could be used for medium
high structures of residential and
commercial occupancy wi

20. STEPPED FOOTING SLOPED FOOTING PAD FOOTING

21. Ring foundation
Ring foundation is a substructure supporting
an arrangement of columns or walls and
transmitting loads to the soil by means of a
continuous Slab. Generally, these foundations
could be used for tall structures, such as,
silos, chimneys, water tanks, etc, which have
a non-uniform distributed loads.

25. RAFT FOUNDATION
Raft foundation is a substructure supporting an arrangement of columns
or walls in a row and transmitting the loads to the soil by means of a
continuous slab with or without openings or depressions. The foundations
are useful where the soil has low bearing capacity.
A raft (mat) foundation slab of
uniform thickness is suitable for
fairly small and uniform column
spacing and when the supporting soil
is not too compressible. The slab
may be thickened for heavily loaded
columns to provide adequate
strength for shear and negative
moment. A slab and beam type of
raft is likely to be more economical
for large column and unequal spacing
of columns; particularly when the
supporting soil is compressible.

26. PILE FOUNDATION The load transfer
mechanism, piles transfer axial load
either by friction along its shaft and/or
subsequently by end bearing.
Construction of pile foundations requires
careful choice of piling system,
depending on the subsoil conditions, the
load characteristics, limitations of total
settlement, differential settlement, etc.

27. Driven Cast in-situ Concrete Pile
Driven cast in-situ piles are formed by driving a casing and filling it in the
hole with plain or reinforced concrete. The casing may be temporary or
permanent. The concrete may be rammed, vibrated or just poured. These
piles find wide application where the pile required is taken to a greater
depth to find adequate bearing strata or to develop adequate skin friction;
and also when the length of individual piles cannot be pre-determined.

28. Bored Precast Concrete Pile
These piles find wide application in chemically agressive soils and in high
ground water conditions. These piles are protected even in such
conditions because they are made by using dense, vibrated matured
construction

29. Under-Reamed-Piles Under-reamed piles find
wide application under the following conditions:
When the site consists of expansive soils, like
black cotton soil, the bulb provides additional
anchorage against uplift due to swelling pressure
impart from the increased bearing. In filled or
otherwise weak strata overlying firm strata,
enlarged base in the form of underreamed bulb
provides larger bearing area and therefore piles
of greater bearing capacity can be constructed.
In loose to medium pervious sandy and silty
strata, the process of compaction increases the
bearing capacity of the pile.

30. FRANKI PILE
The Franki piling system (also
called pressure-injected footing)
is a method used to drive
expanded base cast-in-situ
concrete (Franki) piles