Pad Foundation Lectured by Ms Noorhidayah Sunarti School

Pad Foundation Lectured by: Ms. Noorhidayah Sunarti School of Quantity surveying & Construction Management

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

Functions 1. 2. 3. 4. 5. 6. Prevent settlement (including differential settlement) of a structure Prevent possible movement of structure due to periodic shrinkage and swelling of subsoil Allow building over water or water-logged ground Resist uplifting or overturning forces due to wind Resist lateral forces due to soil movement Underpin (support) existing or unstable structures

Classification of Foundation in general can be classified into a number of ways, such as: 1. Simple, Shallow and Deep foundation 2. Pad/strip type and piled foundation

Examples of shallow foundation

Shallow and piled foundation

Shallow foundation n This type of foundation usually refers to those being rested on stratum with adequate bearing capacity and laid less than 3 m 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 Foundation

Raft Foundation n 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 Foundation

Balanced base Foundation

MEASUREMENT PRINCIPLES ELEMENT: PAD FOUNDATION **refer to drawings – plan , section view n Components: – Reinforced foundation base / concrete pad – Column stump

TAKING-OFF LISTS (items to be measured) n Reinforced foundation base / concrete pad – Concreting works n Reinforced concrete Grade __ in concrete pad / foundation base. (m 3) n Lean Concrete blinding Grade _ under concrete pad / foundation base. (m 2) – Formwork n Sawn formwork to sides of concrete pad / foundation base. (m 2) – Reinforcement works (not available in this task) n High tensile reinforcement bar in concrete pad (kg/m) n Mild steel reinforcement bar in concrete pad (kg/m)

Plan of Pad Foundation 300 mm 1250 mm Nos. of foundation base = 4 nos. Nos. of column stump = 4 nos.

Section of pad foundation G. L 750 mm Column stump 6 R 8 -225 4 Y 20 300 mm Reinforced concrete pad 25 mm Thick lean concrete

TAKING-OFF LISTS (items to be measured) n Reinforced column stump – Concreting works n Reinforced concrete Grade _ in column stump (m 3) – Formwork n Sawn formwork to sides of column stump (m 2) – Reinforcement works (not available in this task) n High tensile reinforcement bar in column stump (kg/m) n Mild steel reinforcement bar in column stump (kg /m)

Piled foundation n n 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 pile

Classification of Piled Foundation n 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 Nonpercussion Piles (form by augering, boring or drilling) 4. Displacement or replacement piles