Attempts to make use of
permanent elements of
construction works to
provide rigidity and bracing
against loadings from ground
Removes need for
temporary support
structures
Speedy and
economical solution to
formation of deep
basements
Possible to commence
formation of
superstructure
simultaneously with
basement construction
Bottom up
Conventional method
Substructure and
superstructure
constructed
sequentially
Bottom of
substructure /
lowest level of
basement to top
of the
superstructure
Not feasible for gigantic projects
with limited construction time
and / or site constraints
Construction approaches
Open excavations
Excavation with temporary support
Excavation with permanent
retaining walls formed prior to
main excavation
Contiguous piles
Secant piles
Diaphragm walls
Foundations
Types
Piled
Strip
Pad
Raft
Soil types
Rock
Gravel and sands
Silts and clays
Functions
Safely transmit building loads to supporting strata,
spreading them over a sufficient area to ensure that
safe load bearing capacity of soil is not exceeded