SOIL MECHANICS-1 DEEP FOUNDATIONS PRESENTATION TOPIC MEMBERS O8-CE-29

FOUNDATION The lowest artificially built part of a structure upon which it directly rests is called foundation Total load is distributed uniformly over a large area to bring intensity of loading within the safe bearing capacity of soil

PURPOSE Distributes the load at a uniform rate over the surface to prevent unequal settlement Prevent the lateral movement Secure a level and firm bed Increase the stability of the structure

FACTORS FOR SELECTION OF FOUNDATION Types and intensity of loads (live load, dead load etc) Nature and bearing of soil on which structure rests

DEEP FOUNDATION The structure which is constructed with some artificial arrangements such as piles , wells etc. at their base TYPES Pile foundations

PILE FOUNDATION A foundation which is supported on piles Piles distribute the load either by friction or by friction combined with bearing at end

APPLICATIONS Used where Soil is soft and hard strata is far below the ground Shallow foundation is expensive High buildings and concentrated loads Buildings along seashore and river bed

TYPES OF PILES Bearing Friction Friction and bearing Batter Guide Sheet

BEARING PILES Rest on hard strata and act as columns to bear load of the structure Application: To bear vertical loads Where hard stratum is easily approachable

FRICTION PILES Bear loads on account of frictional resistance between their outer surface and soil in contact Application: Soil is soft and hard strata unavailable upto considerable depth

FRICTION & BEARING Rest on soft strata and resist load partly by bearing and partly by friction Application: Where bearing capacity of soil under piles is not sufficient to resist load

BATTER PILES Driven at an inclination to resist inclined loads Application: In retaining walls & abutments etc to resist lateral forces

GUIDE PILES Application: In the formation of coffer dams Temporarily constructed for foundations under water

SHEET PILES Thin sheets driven into the ground to enclose an area Application: Are not required to carry loads but to enclose soil and prevent leakage of soft material

METHODS OF CONSTRUCTION Drop hammer method Steam hammer method

METHODS OF CONSTRUCTION Boring

METHODS OF CONSTRUCTION Screwing Water jet

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