Pad FoundationPad Foundation

Lectured by:Lectured by:

Ms. Noorhidayah SunartiMs. Noorhidayah Sunarti

School of Quantity surveying & School of Quantity surveying & Construction ManagementConstruction Management

What is Foundation?What is Foundation?

Foundation is the element of a structure that serves to support the loads super-imposed to it through the transmitting elements (such as columns).

FunctionsFunctions

1. Prevent settlement (including differential settlement) of a structure

2. Prevent possible movement of structure due to periodic shrinkage and swelling of subsoil

3. Allow building over water or water-logged ground

4. Resist uplifting or overturning forces due to wind

5. Resist lateral forces due to soil movement6. Underpin (support) existing or unstable

structures

Classification of Foundation Foundation in general can be classified into a number of ways, such as:

1. Simple, Shallow and Deep foundation2. Pad/strip type and piled foundation

Examples of shallow Examples of shallow foundationfoundation

Shallow and piled Shallow and piled foundationfoundation

Shallow foundationShallow foundation

This type of foundation usually refers to those being rested on stratum with adequate bearing capacity and laid less than 3m below ground level.

Common examples include pad, strip or raft foundations.

A combination of two or three type of shallow foundation in one single structure is not uncommon.

Types of Shallow Types of Shallow FoundationFoundation

Raft FoundationRaft Foundation

Raft foundation is a large combined thick slab designed to seat and support the whole or a large part of a structure.

A raft is usually used when subsoil is weak, or columns are closely located and with deviated loadings.

It also serves as a transfer slab to combine and tie up all the vertical loading elements to the plate-form foundation. By doing so, differential settlement can be avoided.

Types of Shallow Types of Shallow FoundationFoundation

Balanced base Balanced base FoundationFoundation

MEASUREMENT MEASUREMENT PRINCIPLES PRINCIPLES

ELEMENT: PAD FOUNDATIONELEMENT: PAD FOUNDATION

**refer to drawings – plan , section **refer to drawings – plan , section viewview

Components:Components:– Reinforced foundation base / Reinforced foundation base /

concrete padconcrete pad– Column stumpColumn stump

TAKING-OFF LISTS TAKING-OFF LISTS (items to be measured)(items to be measured)

Reinforced foundation base / concrete padReinforced foundation base / concrete pad

– Concreting worksConcreting works Reinforced concrete Grade __ in concrete pad / Reinforced concrete Grade __ in concrete pad /

foundation base. (m3)foundation base. (m3) Lean Concrete blinding Grade _ under concrete pad / Lean Concrete blinding Grade _ under concrete pad /

foundation base. (m2)foundation base. (m2)

– FormworkFormwork Sawn formwork to sides of concrete pad / foundation Sawn formwork to sides of concrete pad / foundation

base. (m2)base. (m2)

– Reinforcement worksReinforcement works (not available in this task)(not available in this task) High tensile reinforcement bar in concrete pad High tensile reinforcement bar in concrete pad

(kg/m)(kg/m) Mild steel reinforcement bar in concrete pad (kg/m)Mild steel reinforcement bar in concrete pad (kg/m)

Plan of Pad FoundationPlan of Pad Foundation

1250mm

1250mm

300mm

300mm

Nos. of foundation base = 4 nos.

Nos. of column stump = 4 nos.

Section of pad foundationSection of pad foundation

6R8-225

4Y20

G.L

25mm Thick lean concrete

300mm

750mm

Reinforced concrete pad

Column stump

TAKING-OFF LISTS TAKING-OFF LISTS (items to be measured)(items to be measured)

Reinforced column stumpReinforced column stump

– Concreting worksConcreting works Reinforced concrete Grade _ in column stump (m3)Reinforced concrete Grade _ in column stump (m3)

– FormworkFormwork Sawn formwork to sides of column stump (m2)Sawn formwork to sides of column stump (m2)

– Reinforcement worksReinforcement works (not available in this task)(not available in this task) High tensile reinforcement bar in column stump High tensile reinforcement bar in column stump

(kg/m)(kg/m) Mild steel reinforcement bar in column stump (kg /m)Mild steel reinforcement bar in column stump (kg /m)

Piled foundationPiled foundation

Piled foundation is a form of foundation using piles to transfer the loads of a structure down to a firm soil stratum with sufficient load-taking capacity.

Materials for the piles can be of:– Timber– Pre cast concrete (sometimes also pre-

stressed)– In-situ reinforced concrete– steel piles in ‘H’ or circular section

Loading supports to Loading supports to pilepile

Loading supports to Loading supports to pilepile

Classification of Piled Foundation Piled Foundation can be classified into:

1.End Bearing pile or Friction pile (or of combined nature)

2.Piles formed by manual or mechanical methods

3.Percussion Piles (driven by hammer) or Non-percussion Piles (form by augering, boring or drilling)

4.Displacement or replacement piles