Appendix D Geotechnical report · MCU18/0013

Project No. 304-2014
November, 2004 Page 13

6.4 Slab On Ground

6.4.1 General

The field test results indicate that the existing natural soils, along with any controlled fill,
are suitable for slab on ground construction provided that site preparation earthworks are

carried out in accordance with recommendations in Sections 6.1 and 6.2.

In addition, as noted in Section 6.3.1, the slab on ground floor should be designed to

accommodate the anticipated potential ground surface movement.

6.4.2 Sub-Base

It is suggested that a 150mm layer of sub-base be provided under all concrete slabs.
The sub-base material should be compacted to a density not less than 95% of maximum
dry density in accordance with AS.1289 5.2.1 (Modified compaction). The sub-base is

provided under a concrete slab to:-

* Provide a stable ‘working platform’ on which to operate construction equipment;

* Facilitate the provision of a uniform bearing surface under the slab.

Sub-base material should be of good quality conforming to requirements (minimum) of
Material Type 2.4 as specified in the Queensland Department of Transport, Standard
Specification MRS 11.05, Unbound Pavements (December, 1993).

6.5 Retaining Walls
6.5.1 General

It is understood that retaining walls would be required for the construction of the
proposed ground floor. We understand the expected maximum retained height will be up

to 6 metres.

The lateral earth pressure distribution that effects the retaining walls on the site will

depend upon the following parameters :-

¢  Insitu and backfill material properties

* Design water regime at the rear of the wall
¢ Wall and cut geometry

* Surcharges effecting the wall

¢ Wall type

* The structural bracing of the wall and the timing of backfilling behind the wall

 

#F SOIL SURVEYS ENGINEERING