01.1 - Geotechnical Report · OPW18/0008

Page 2

HRDESIGNGROUP

Cromar Winning Consulting Engineers Pty LTD T/A
ABN30 169 626 957 DESIGN @ROUP

Office: Suite 8, 137 Brisbane Road, Mooloolaba QLD 4557
Postal: PO Box 7117, Sippy Downs, QLD 4556
Phone: (07) 5444 5578

 

 

 

 

 

Email: [email protected]

Web: www.hrdesigngroup.com.au

Client: Ryan Designer Homes

Job Number: 17-0417

Site: Lot 120 Seamount and Mermaid Quays, Noosa Waters
Date Investigated: 42" July 2017

1.0 INTRODUCTION

The purpose of this report is to classify the residential site identified above, in accordance with AS2870-2011 -
"Residential Slabs and Footings".

Boreholes have been drilled in the area of the proposed development to obtain a sample, representative of the surface
and sub-surface soil strata for laboratory testing and evaluation of characteristic surface movement.
2.0 SITE DESCRIPTION

See the attached report No.11481 by “CSI: Construction Site Investigations”.

3.0 SITE SKETCH

See the attached.

4.0 SOIL PROFILE

Two (2) boreholes were drilled in the proposed building envelope, positions shown on attached site sketch. The soil
profiles are as shown on the attached borelogs by “CSI: Construction Site Investigations’.

No water table was encountered during site investigation.

The site was found to be filled to 1900mm below test surface level. After examining the fill on site and the results of
investigation, it is apparent that an attempt was made to compact the fill under controlled conditions. However as
certification is not available to define this fill as “Controlled Fill", we are required by AS2870 to classify this site as
Class 'P’.

5.0 SITE CLASSIFICATION

Based on the soil profiles encountered during site investigation, and the results of field and laboratory testing, the
natural classification of this site is Class 'S'.

However, due to the presence of uncontrolled fill which currently exists on this site, we are required by AS2870 to
classify this site as Class ‘P’.

§.1 Effect Of Earthworks On Site Classification
This site classification is based on the soil profile encountered. The extent of further earthworks is unknown.

The classification must be reconsidered if the depth of cut varies by more than 300mm or the depth of fill varies by
300mm or exceeds the limits provided in Clauses 2.5.3 and 6.4.2 of AS2870-2011

 

HRDESIGNGROUP Reference No: 17-0417 Page 7 of 5

 

Page 3

aa)

DESIGN GROUP <

    
 

 

6.0 RECOMMENDATIONS

Due to the shape and size of the proposed house we recommend that footings are designed based on an appropriate
waffle raft slab deepened with steel screw piers founded in dense natural sands. Alternatively, foundations could be
designed as a conventional stiffened raft slab subject to further geotechnical investigation to confirm the adequacy
and consistency of the existing sand fill.

After the final building platform is created, ensure that positive drainage exists away from the house area. Use a
minimum surface gradient of 1 in 10, or 50mm, away from the footing beams for at least one (1) metre.

Existing or proposed trees shall be kept a minimum distance equal to their mature height away from the footings.
Where rows or groups of trees are involved, the distance from the building should be increased. Root barriers are to
be installed if these trees are likely to affect foundation performance.

Contact this office for full foundation details once house plans are completed.
7.0 QBCC COMPLIANCE

This building site foundation investigation and classification has been undertaken in accordance with AS 2870
“Residential slabs and footings”. The Queensland Building and Construction Commission’s Rectification of Building
Work policy has a requirement for the following information to be supplied to us by the builder, and that we consider
this information in determining the site classification. (Information available at time of classification is indicated by KX]
below)

EX] Information to correctly identify and locate the site;
&X] Contours of the site;

KX Location of existing trees;

LI Overland flow paths;

(J Building footprint and platform level;

( Relevant land search information.

8.0 DRAINAGE
At no time during construction, or after, is water to be permitted to pond in or near footings. Ensure all fill batters away
from the final house, making sure all surface runoff is directed away from the house. (Maximum batters are to be -

1:1.5 for clay soils, and 1:1.7 for sand soils.)

All roof drainage to be discharged either to the street, or into the Local Authority's stormwater system or in accordance
with the Local Authority's requirements.

All external patio, carport and verandah slabs to be graded at not less than 1 in 100 to remove all surface water away
from the house area.

9.0 OWNER’S RESPONSIBILITIES

Stable moisture conditions near the footings, is the responsibility of the owner/occupier of the dwelling. Large changes
in moisture conditions around the structure’s footings, will cause movement, and may lead to damage of the house.
This report must be read in conjunction with the attached report, "Guide to Home Owners on Foundation Maintenance
and Footing Performance", sheet No. 10-91, produced by Dr P.F. Walsh of the CSIRO.

10.0 REPORT LIMITATIONS

Recommendations given in this report are based on the findings of the soil investigation attached. Any change to the
building location may require further investigation and analysis.

Every reasonable effort has been made to locate test sites so that the bores are representative of the soil conditions
within the area of construction. The client should be made aware that exploration is limited by time available and by

 

HRDESIGNGROUP Reference No: 17-0417 Page 2 of 5

 

Page 4

a)

DESIGN GROUP.

  
   

 

economic constraints. If soil conditions differ from those of the log sheet attached during excavation or construction,
please notify this office immediately for further inspection and recommendations.

The Local Authority and/or property owner/builder should check their records and advise this office of any elements
that they are aware could influence the site classification, eg. Cutting and filling of the site.

Our definition of rock in this case is the same as the definition in AS2870 “A strong material including shaley material
and strongly cemented sand or gravel that does not soften in water. Materials that cannot readily be excavated by a
backhoe may be taken to be rock”. Therefore, in our opinion, a backhoe using a 300mm wide bucket will have
difficulty in excavating below the depth where we were unable to penetrate. We assume that the backhoe is in good
condition and is similar in power to a Case 580 series (or a MF50).

In writing this report we have considered all the information supplied to us by our client. Should the client or his agent
have omitted to supply us with relevant information, our report may be irrelevant and/or inappropriate. We do not take
responsibility for the consequences in such cases, and we will make an additional charge if as a result, more testing or
re-writing of the report is necessary.

This report has not taken into consideration the long term effect of any previous, current or potential subsurface work
by mining companies. At the time of writing this report, neither our client, (or his agent) or the Local Authority had
made us aware that surface mining may be affecting this allotment in any way.

11.0 REPORT OWNERSHIP

This report has been prepared for the client/s listed at the beginning of the report. Use of this report by any other party
is prohibited without the express written permission of HR Design Group. HR Design Group retains the ownership of
this report until such time that all outstanding fees and monies have been received at the office of HR Design Group.

HR Design Group
Cromar Winning Consulting Engineers Pty Ltd T/A

 

Dated: 1 August, 2017.

 

HRDESIGNGROUP Reference No: 17-0417 Page 3 of 5

 

Page 5

WIND CLASSIFICATION TO AS4055-2012 a

 

 

Client: Ryan Designer Homes
Job Number: 17-0417
Site: Lot 120 Seamount and Mermaid Quays, Noosa Waters

The following parameters have been applied to AS 4055 — Wind Loads for Housing, in order to evaluate the design
wind classification for the building site. If the building is not a residential house, then AS 4055 does not apply, and
the parameters described herein are a guide only to the determination of a design wind velocity and pressures based
only upon AS/NZS 1170.2-2011.

Building Region: B
Terrain Category: Tc3
Topographic Classification: TO
Shielding Classification: FS

DESIGN WIND CATEGORY: N2

Should you require any more assistance, please do not hesitate to contact my office.

HR Design Group
Cromar Winning Consulting Engineers Pty Ltd T/A

 

Barry R Cromar B€ng (civil), MiEAust CPEng RPEQ NPER
wae
ABN

Dated: 1 August, 2017.

 

HRDESIGNGROUP Reference No: 17-0417 Page 4 of 5

 

Page 6

a io

DESIGN GROUP

 

 

APPENDIX

e SITE INVESTIGATION REPORT

 

HRDESIGNGROUP Reference No: 17-0417 Page 5 of 5

 

Page 7

CsI sou TESTING

What are you Building on ?

 

SITE INVESTIGATION REPORT

 

 

Client: HR Design Group HR17-0417

CSI Job No: 11481

Site Address: Lot 120 Cnr Seamount & Mermaid Quays, Noosa Waters
Council: Noosa Shire

Field Work By: BAC

Date of Field Work: 10/07/17

Reported By: BAC

Report Date: 12/07/17

In accordance with AS1726-1993 AS2870-2011

 

CSI: 11484Lot120CnrSeamount&MermaidQuaysNoosaWaters

Creabian p/l atf....abn 17108178312 ....PO Box 1128, BUDDINA Q 4575
1300 762 240, 0418 708 636 / 07 5493 5966. [email protected] www.csisoiltesting.com.au

 

 

Page 8

CSI sou TESTING

What are you Building on ?

 

 

 

Site Report
CLIENT: HR Design Group HR17-0417 CSI JOB NUMBER: 11481
SITE ADDRESS: Lot 120 Cnr Seamount & Mermaid Quays, Noosa | DATE TESTED: 10/07/17
Waters TESTED BY: BAC
TEST METHOD: Hydraulic Rig IN ACCORDANCE WITH
AS1726-1993 AS2870-2011

 

 

 

VEGETATION: Well grassed. Medium/large trees near boundaries of adjacent block(s)
TOPOGRAPHY: Low lying, filled, alluvial area. Marine clay possible in area. Canal to rear. Fair drainage
STRATA SUMMARY: Sand fill over natural alluvial sand

CROSS FALL: Approx. level. Embankment at rear, falling to canal. See contour plan

WIND RATING: Region B, TC2.5, TO, PS

This report does not constitute a slope stability assessment, if the local authority deem it necessary for a slope
stability assessment to be done, a specialist Geo-technical engineer will need to be consulted.

During and after construction, site drainage must direct all surface, subsurface and roof water away from any
construction and toward stormwater run-off areas. It is the owners responsibility to ensure stable moisture
conditions around the structure at all times. Guidance can be found in the CSIRO information sheet ‘Guide to
Home Owners on Foundation Maintenance and Footing Performance’ or the QBCC booklet ‘Guide to Preventing
Structural Damage to your Home’.

The design engineer should be aware of the presence of trees on or near the site and that they may have an effect
on the performance of the footings/slab, whilst in place and after removal. The design engineer should take ail
considerations and satisfy themselves in this regard.

Although marine clays were not encountered in this investigation, the design engineer should always be aware of
the potential, large or small, of deep seated compressible marine clays in the area. Further in-depth investigation
would be required to determine the presence of marine clays.

This report is based on site information as at the time of investigation. A borehole sample is a very small snapshot
of the whole site volume and soil conditions can change over the site. If after excavation of the site footings, the soil
profile is significantly different to that indicated on the attached borelogs, or if the house is situated in a different

location as that marked on the site sketch or if any material change has occurred to the site, this report will become
void. This office is to be notified of such occurrences, so as a new investigation can be carried out (further charges

will apply).

Reported by

B.A.Croke

Assoc Dip Civil Eng

QBCC Site Classifiers Lic No. 1064963

CSI: 14481Lott20CnrSeamount&MermaidQuaysNoosaWaters

Creabian p/l atf....abn 17108178312 ....PO Box 1128, BUDDINA Q 4575
1300 762 240, 0418 708 636 / 07 5493 5966. [email protected] www.csisoiltesting.com.au

 

Page 9

 

_€SI ‘sou TESTING

What are you Building on ?

Field Investigation Data

 

 

 

 

 

 

 

 

 

age oeath dcp (BH) Borehole No.1 Comments
{m)
2 01 . 7 : . .
2 0.2 0.0 Silty SAND (SM), fine to medium grained, dark grey, moist, medium dense (FILL)
4 0.3
6 0.4 0.4 Silty SAND (SM), fine to medium grained, yellow brown, moist, dense (FILL)
9 0.5
5 ae 1.6 Silty SAND (SM), fine to medium grained, dark grey, wet, medium dense
4 ps 2.0 SAND (SP), fine to medium grained, light grey, wet, dense
9 1.0 .
9 44 6.0 Terminated
8 1.2
5 1,3
4 14
3 1.5
3 1.6
3 17
7 1.8
10 1.9
1 2.0
11 2.1
12 2.2
7 23
8 24
15 2.5
15 2.6
13 27
10 2.8
8 2.9
3.0
oF | death | OOP (BH) Borehole No.2 Comments
(m)
1 0.1
3 02 0.0 Silty SAND (SM), fine to medium grained, dark grey, moist, medium dense (FILL)
5 0.3
4 0.4 0.3 Silty SAND (SM), fine to medium grained, brown, moist, dense (FILL)
8 0.5
10 aS 0.7 Silty SAND (SM), fine to medium grained, yellow brown, moist, dense (FILL)
ie 08 1.9 Silty SAND (SM), fine to medium grained, grey, wet, medium dense
14 1.0
419 14 2.5 SAND (SP), fine to medium grained, light grey, wet, dense
16 1.2
14 1.3 7.0 Terminated
14 1.4
10 1.5
5 1.6
6 V7
3 1.8
2 1.9
2 2.0
1 2.1
1 2.2
a 2.3
5 24
8 2.5
10 2.6
7 2.7
7 2.8
7 29
3.0

 

CSI: 11481tLoti20CnrSeamount&MermaidQuaysNoosaWaters

Creabian p/i atf....abn 17108178312 ....PO Box 1128, BUDDINA Q 4575

1300 762 240, 0418 708 636 / 07 5493 5966. [email protected] www. csisoiltesting.com.au

 

 

Page 10

 

 

 

 

60/2 ager | soisza auwNiiunaue PID
aug selon ten, uayemeroon | > Sein

Zoey oat sem TBE | yy Sretoemerrwgt orem tans cate
Sow wore | aenpwuneweasartiot | \,4/

vw acanezt lara ang patodaag Aad st Auedeyy | ewWS}9)

 

spmmeeeioeouren nme -apeeretame aren besos
~uaamgmeemmsiiars meccmemeen| Le te Boe
Sara Se sl seus] wtameneaf ae

  

Rnterpemenst afte pucmaune nap acren ig nett a ee
ecctanen por comaigar eH Ne PANS MPN Ne

 

Page 11

csi sou TESTING

What are you Building on ?

 

Photos

 

CSI: 11481Lot120CnrSeamount&MermaidQuaysNoosaWaters

Creabian pAl alf....abn 17108178312 ....PO Box 1128, BUDDINA Q 4575
1300 762 240, 0418 708 636 / 07 5493 5966. [email protected] www. csisoiltesting.com.au

 

Page 12

CSI sou TESTING

What are you Building on ?

 

 

 

CSE 11481Lot120CnrSeamount&MermaidQuaysNoosaWaters

Creabian pA atf....abn 17108178312 ....PO Box 1128, BUDDINA Q 4575
1300 762 240, 0418 708 636 / 07 5493 5966. [email protected] www.csisoiltesting.com.au