Weier Group geotech · MCU17/0523

PO Box 171 Wamuran Qld 4512

: 296 Old North Road, Wamuran Qld 4512
AGNER Phone: 07 5496 6715
Mobile: 0438 924 637

Fax: 07 5496 6717
Email: [email protected]
ABN: 49 416 679 791 Web: www.wagnersoiltesting.com.au

Definitions

Definitions to help you understand your report

Table 2.1
GENERAL DEFINITIONS OF SITE CLASSES

 

Class Foundation

A . Most sand and rock sites with little or no ground movement from
moisture changes
Slightly reactive clay sites with only slight ground movement from
moisture changes
Moderately reactive clay or silt sites, which can experience moderate
ground movement from moisture changes
Highly reactive clay sites, which can experience high ground movement
from moisture changes
Extremely reactive sites, which can experience extreme ground
movement from moisture changes
Ato P Filled sites

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

 

 

 

 

x; S| w

 

 

 

 

 

 

 

Table 2.3
CLASSIFICATION BY CHARACTERISTIC SURFACE MOVEMENT

 

Surface Movement Primary classification of site
Ys < 20 mm Slightly reactive (S)
20 mm < Ys < 40 mm Moderately reactive (M)
40 mm < Ys < 60 mm Highly reactive (H1)
60mm <Ys <75mm Highly reactive (H2)
Ys > 75 mm Extremely reactive (E)

 

 

 

 

 

 

 

 

 

Characteristic surface movement (Ys) is the vertical movement range expected during the life of the house
from a reasonable estimate of dry conditions to a similar estimate of wet conditions and does not take into
account the moderating effect of the footing system. The Standard nominates 50 years as the ‘life’ of the

house and ‘reasonable’ as the level that could be expected for 19 houses out of every 20.

The effects of trees, poor site drainage, leaking plumbing and exceptional moisture-induced movements as
outlined in Clause 1.3.3 of AS2870 are not taken into account in the calculation of Ys.

The purpose of site investigation is to provide sufficient information to enable a site classification to be
made, and to include information on the presence and depth of fill material, natural soil profile, and soil
reactivity where required.

Class A, S, M, H an E sites shall have adequate allowable bearing pressure. The allowable bearing
pressure at a foundation level shall be not less than 100 kPa for strip and pad footings, and under the
edge footing of footing slabs used without tie bars between the edge footing and slab. The allowable
bearing pressure at foundation level shall be not less than 50 kPa under all beams and slab panels and
support thickenings for slab construction.

CONSTRUCTION MATERIALS TESTING