Foundations

Question 1

What is a Pad Foundation?

Answer 1

Generally a concrete slab (Pad) To support single point loads such as columns, groups or columns for framed structures.

Starter bars are left sticking out of the concrete pad so they can be connected to the column started bars

Question 2

Why would you use a strip foundation?

Answer 2

Strip foundations are used to provide a continuous strip of support to a linear structure such as a wall or closely-spaced rows of columns built centrally above them

Question 3

What is a raft foundation?

Answer 3

Raft foundations are formed by reinforced concrete slabs that cover the entire footprint of a building.

They spread the load imposed by a number of columns or walls over the area of foundation, and can be considered to ‘float’ on the ground as a raft floats on water.

Question 4

Why would you use a raft foundation?

Answer 4

Generally used when ground conditions are poor and there is a risk of settlement or differential settlement

Or when it is impractical to create a large number of strip or pad foundations

Question 5

When would you use a pad foundation?

Answer 5

Generally suitable where the bearing capacity of the ground is sufficient at relatively low depths and minimal excavation is required

Pad foundations are an econicaly / cheap solution

The CANNOT be used in bad soil conditions or point loads are high - Not suitable for a high rise building