NCC 2019 Volume Two
Part 3.2.4 Site classification

Part 3.2.4 Site classification

3.2.4.1 Site classification

The foundation where the footing is to be located must be classified in accordance with AS 2870.

Explanatory information:

Explanatory information:

Table 3.2.4.1 provides a general description of foundation soil types that will assist in the classification of the site. More detailed information, including differentiation between classifications, can be found in AS 2870 or alternatively contact the appropriate authority.

Due to the limitations of this Part, if a site is classified as E or P then reference must be made to AS 2870 for design and construction information.

Table 3.2.4.1 General definition of site classes

Class

Foundation

A

Most sand and rock sites with little or no ground movement from moisture changes

S

Slightly reactive clay sites with only slight ground movement from moisture changes

M

Moderately reactive clay or silt sites which can experience moderate ground movement from moisture changes

H

Highly reactive clay sites which can experience high ground movement from moisture changes

E

Extremely reactive clay sites which can experience extreme ground movement from moisture changes

A to P

Filled sites — see AS 2870

P

Sites which include soft soils, such as soft clay or silt or loose sands; landslip; mine subsidence; collapsing soils; soils subject to erosion; reactive sites subject to abnormal moisture conditions or sites which cannot be classified otherwise

Note to Table 3.2.4.1: For classes M, H and E further division based on the depth of the expected movement is required. For deep-seated movements, characteristic of dry climates and corresponding to a design depth of suction change Hs, equal to or greater than 3 m, the classification shall be M-D, H-D or E-D as appropriate. For example, H-D represents a highly reactive site with deep moisture changes, and H represents a highly reactive site with shallow moisture changes.