Footings & Foundations

FOUNDATIONS (WORKING DRAWING)

P.BY:

Ar. ANMOL GARG (Lecturer, Deptt. of Architectural Assistantship)

GOVT. POLYTECHNIC COLLEGE, BATHINDA

Cont.: 09914410599

Footings & Foundations

INTRODUCTION TO FOUNDATIONS

Function of a foundation is to transfer

the structural loads from a building

safely into the ground.

A larger and heavier building of

masonry, steel, or concrete would

require its foundations to go deeper

into earth such that the soil or the rock

on which it is founded is competent to

carry its massive loads.

Footings & Foundations

Foundation Components

Footing

Footings & Foundations

Foundation Components

(to attach wood stud sill plate)

(to keep water off of foundation wall)

(separates slab from foundation wall)

(to keep water off of slab)

(to keep water off of slab & moisture barrier) (moves water away from building)

(moves water away from building)

Footings & Foundations

Site Preparation

•Remove trees and any debris

•Remove top soil (4-6” below surface)

Footings & Foundations

Site Layout

•Ensure lot lines are known & setbacks are complete

•Layout building perimeter

•Use batter boards

•Establish building corners & building perimeter

•Use surveying instruments

Footings & Foundations

Excavation

•Excavate foundation along line created by batter boards

•Excavate remainder of soil inside perimeter

•Don’t excavate inside soil if slab on grade

•If deep foundation, taper edges to prevent collapse

•If soil unstable, or very deep - use shoring

Footings & Foundations

Pour Footings •Construct formwork (if required)

•Install reinforcement (rebar) for footings

•(protrudes above footing to tie-into

foundation wall)

•Pour concrete footings

•Smooth / finish surface

Footings & Foundations

Rules of Thumb

•Footing shall be below frost line

•Footing width usually 2x height

•Typical size (24” wide x 12” tall)

•Rebar is usually 3” from edge of concrete

•Crawl spaces should have rigid insulation

along the interior face of the foundation wall

Footings & Foundations

TYPES OF FOUNDATION

Major Building Parts

Superstructure

Substructure

Foundation

Footings & Foundations

TYPES OF FOUNDATION

Two types foundations : Shallow and

Deep –

Depends on whether the load transfer is at

deeper depths or shallower depths

- Need for these two types (soil strength,

ground water conditions, foundation loads,

construction methods and impact on

adjacent property)

Footings & Foundations

TYPES OF FOUNDATION

Shallow foundations (column footings

without or with tie/grade beams, individual

or combined wall footing, slab on grade,

raft)

- Deep foundations (caissons with or

without sockets, end bearing or friction

piles, pile groups), made of concrete

(regular or site-cast) or steel or wood

Footings & Foundations

Shallow Foundations

� Requirements

–Suitable soil bearing capacity

–Undisturbed soil or engineered fill

� Basic types or configurations

–Column footings

–Wall or strip footings

Footings & Foundations

Combination Spread & Strip Footing

Footings & Foundations

Shallow Foundations

Stepped strip

footings

Grade Beams

/// \\\

\\\ \\\

///

///

Footings & Foundations

Shallow Foundations

�Mat foundation

�Floating (Mat)

foundation

Footings & Foundations

Deep Foundations - Purpose

Transfer building loads deep into the earth

Basic types

– Drilled (& poured)

– Driven

Footings & Foundations

Pile material

� Steel; H- piles, Steel pipe

� Concrete; Site cast or Precast

� Wood; Timber

� Composite

Footings & Foundations

Driven Piles

Footings & Foundations

Precast Concrete Plies

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

Footings & Foundations

P.BY:

Ar. ANMOL GARG (Lecturer, Deptt. of Architectural Assistantship)

GOVT. POLYTECHNIC COLLEGE, BATHINDA

Cont.: 09914410599