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Report to Johannesburg Development Agency (Pty) Ltd on

the Results of a Shallow Geotechnical Investigation for the

Proposed Central Fire station, Johannesburg, Gauteng

Geotechnical Engineering Services

Engineering Geology

Environmental and Groundwater

Pile Integrity Testing

SANAS Accredited Soil & Rock Laboratory

Earthworks/Materials Supervision & Control

Geotechnical Monitoring Systems

Road Pavement Materials and Design

Project Management

Reference: 015-18.R01

Dated: 20 February 2018

Geosure (Pty) Ltd www.geosure.co.za 015-18.R01

Report to Johannesburg Development Agency (Pty)

Ltd on the Results of a Shallow Geotechnical

Investigation for the Proposed Central Fire station,

Johannesburg, Gauteng

Reference : 015-18.R01

Dated : 20 February 2018

GEOSURE (PTY) LTD Geotechnical, Environmental & Groundwater Engineering Consultants

Civil Engineering Soils Laboratory

Head Office & Laboratory

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Document Control Record

Document prepared by:

Geosure (Pty) Ltd

122 Intersite Avenue

Umgeni Business Park

Durban

South Africa

4001

Tel: 031 266 0458

Fax: 086 689 5506

E-mail: [email protected]

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Document Control

Report Title Report to Johannesburg Development Agency (Pty) Ltd on the Results of a

Shallow Geotechnical Investigation for the Proposed Central Fire station,

Johannesburg, Gauteng Report Reference 015-18.R01 Responsible Person Ms. J. Jacobs

Client Name Johannesburg

Development Agency

Client Contact Details

[email protected]

Revision Date Revision Details/Status Author Reviewer

0 20/02/2018 Geotechnical report with

recommendations Mr N. Govender Mr F. Smith

Current Revision

0

Approval

Author Signature

Reviewer Signature

Name Nishen Govender

Pr. Sci. Nat Name

Francis Smith

Pr. Sci. Nat

Title Technical Manager Title Associate


http://www.geosure.co.za/



Abbreviations and definitions

Abbreviation Definition

AASHTO American Association of State Highway and Transportation

CBR California Bearing Ratio

DCP Dynamic Cone Penetrometer

E East

EGL existing ground level

Geosure Geosure (Pty) Ltd

GM grading modulus

IMC insitu moisture content

IP inspection pit

JDA Johannesburg Development Agency

JMPD Johannesburg Metropolitan Police Department

k Coefficient of Permeability

kN/m2 kilonewtons per metre square

LL liquid limit

LS linear shrinkage

m metre (s)

MDD maximum dry density

mm millimetre

No. number

N North

OMC optimum moisture content

PI plasticity index

SANS South African National Standards

S South

TLB Tractor Loader Backhoe

TRH Technical Recommendations for Highways (1985)

Unified Soil Classification

GC Clayey GRAVEL

SC Clayey sands to sandy silt mixtures

SM Sandy silts and sand-silt mixtures

SP Poorly graded SAND


Report to Johannesburg Development Agency (Pty) Ltd on the

Results of a Shallow Geotechnical Investigation for the Proposed

Central Fire station, Johannesburg, Gauteng

Reference: 015-18.R01 Date: 20 February 2018

TABLE OF CONTENTS

1. TERMS OF REFERENCE ............................................................................................................................. 1

2. SCOPE OF REPORT ...................................................................................................................................... 1

3. GUIDELINES FOR INVESTIGATION ........................................................................................................ 1

4. INFORMATION USED .................................................................................................................................. 2

5. SITE DESCRIPTION ...................................................................................................................................... 2

6. FIELDWORK .................................................................................................................................................. 4

6.1 TERRAIN RECONNAISSANCE .......................................................................................................................... 4 6.2 INSPECTION PITS ............................................................................................................................................ 4 6.3 DYNAMIC CONE PENETROMETER LIGHT (DPL) TESTS .................................................................................. 5

7. INFERRED GEOLOGY AND ANTICIPATED SUBSURFACE CONDITIONS ..................................... 5

8. GROUNDWATER ........................................................................................................................................... 8

9. LABORATORY TESTING ............................................................................................................................ 8

10. DISCUSSION ..................................................................................................................................................10

10.1 PROPOSED DEVELOPMENT ............................................................................................................................10 10.2 UNDERMINING ACTIVITY BENEATH THE SITE ...............................................................................................10 10.3 MATERIAL CLASSIFICATION AND RECOMMENDATIONS FOR USAGE .............................................................10 10.4 EXCAVATION CHARACTERISTICS ..................................................................................................................11 10.5 GENERAL EARTHWORKS ...............................................................................................................................11 10.6 FOUNDING CONDITIONS ................................................................................................................................12 10.7 FOUNDATION RECOMMENDATIONS FOR THE FIRE STATION ..........................................................................12

10.7.1 Reinforced Concrete Strip Footings on Improved Ground ......................................................................13 10.7.2 Reinforced Concrete Raft on Improved Ground ......................................................................................13

10.8 FOUNDATION RECOMMENDATIONS FOR THE TOWER ....................................................................................14 10.9 DRAINAGE ....................................................................................................................................................14

11. SUPPLEMENTARY GEOTECHNICAL INVESTIGATION FOR THE PROPOSED TOWER

STRUCTURE ANCHORING POINTS ........................................................................................................15

12. SUMMARY AND OBSERVATIONS ...........................................................................................................15

13. REFERENCES ................................................................................................................................................16

Appendix A: Inspection Pit Profiles

Appendix B: Results of Dynamic Cone Penetrometer Light (DPL) Tests

Appendix C: Results of Laboratory Tests

Figure 1: Site Plan

1


Report to Johannesburg Development Agency (Pty) Ltd on the Results of

a Shallow Geotechnical Investigation for the Proposed Central Fire

station, Johannesburg, Gauteng

Reference: 015-18.R01 Date: 20 February 2018

1. TERMS OF REFERENCE

Geosure was requested by Johannesburg Development Agency (Pty) Ltd to provide a

proposal and cost estimate to carry out a geotechnical investigation for the construction of

the New Central Fire Station.

In this regard, JDA issued a tender document titled “A full geotechnical investigation for

the construction of the New Fire Station Project” and dated 27 July 2017.

Geosure completed the abovementioned tender document and submitted it to the Client

under cover of a letter dated 07 August 2017 and referenced p450-17 (New Central Fire

Station)/ng.

Subsequently, Geosure was appointed and authorised by JDA, hereafter referred to as “the

Client”, in a letter of appointment dated 03 January 2018 to proceed with the investigation

as proposed.

2. SCOPE OF REPORT

This report details the results of a shallow geotechnical investigation for the proposed New

Central Fire Station in Johannesburg, Gauteng.

The slope and subsurface conditions at the positions profiled on the site are described and

comment is made on the general stability of the site. Recommendations for earthworks,

drainage, materials excavatability, foundations, materials usage and comment regarding

any mining activity beneath the site, are made.

3. GUIDELINES FOR INVESTIGATION

The fieldwork for the investigation was carried out according to guidelines relevant to

geotechnical investigations of this nature.

The formation and weathering of geological materials are discontinuous processes and

unexpected variations in soil, rock and groundwater regimes may occur even on sites

where the conditions seem to be uniform or consistent. Variations in what is reported here

may become evident during construction and it is thus imperative that an appropriately

qualified and experienced Competent Person inspects all critical stages of development

including, but not limited to, excavations to assess the conditions encountered and to assist

in the interpretation of observations at variance with the information supplied in this report.

This report was prepared for use by the Client and their professional team for the purpose

stated and should not be relied upon for any other purpose.

2


4. INFORMATION USED

The following information was referenced to assist with the fieldwork and preparation of

this report in the investigation:

i. A digital copy of a survey drawing no. AAM/12814A/01, titled “Topographic

Survey of Proposed Central Johannesburg Fire Station”, dated 02 August 2017

and prepared by Geomatics to a scale of 1:500;

ii. A 1:250 000 Regional Geological Map titled “2628 Eastrand”, dated 1986 and

published by the Council for Geoscience of South Africa; and

iii. Low resolution aerial imagery sourced from Google Earth (2018).

5. SITE DESCRIPTION

The site is located within the Johannesburg Central Business District at approximate

latitude and longitude 26.209913 S and 28.043734 E, respectively. Existing development

comprises an impound parking area which is managed by Johannesburg Metropolitan

Police Department (JMPD).

Two structures were observed on site, namely, a newly developed office block and a guard

house.

Significant rutting was observed along the parking areas with many areas being water

logged from recent rainfall activity. Palisade fencing surrounds the site with the JMPD

grounds forming the southern boundary and office blocks forming the northern and eastern

boundaries.

Topographically, the site is relatively flat to gently sloping towards the north, after a

significant infilling exercise to raise ground levels to their present levels.

Plate 1 overleaf provides an indication of the site locality whilst Plates 2 and 3 overleaf

provide a general view of the site.

3


Plate 1: Locality Plan (sourced from Google Earth)

Plate 2: View of the site from the south showing the water logged areas on site

N

4


Plate 3: View of the site from the west

6. FIELDWORK

The fieldwork for the investigation was carried out over the period 29 January 2018 to 02

February 2018 and comprised the following:

i. Terrain Reconnaissance;

ii. Inspection Pits; and

iii. Dynamic Cone Penetrometer Light (DPL) tests.

6.1 Terrain Reconnaissance

A walkover reconnaissance was carried out to gauge site accessibility, for the investigation

activities, and to map and photograph features of major geotechnical significance,

including general earthworks carried out, landform, surface geology and general drainage

patterns.

6.2 Inspection Pits

Twelve inspection pits, designated IP1 to IP12, were excavated using hand tools at the

approximate positions given in Figure 1, included at the end of this report. The inspection

pits were advanced to 1.2m below EGL. Thereafter, a hand auger was used to extend the

pits to refusal/final depths in the range 1.0m (IP11 refers) to 2.7m (IP1 refers) below EGL.

The inspection pits were profiled using the South African Geoterminology Guidelines

(Brink and Bruin, 2002). Disturbed samples were retrieved and the inspection pits were

reinstated on completion of profiling and sampling. Copies of the detailed profiles are

given in Appendix A.

5


6.3 Dynamic Cone Penetrometer Light (DPL) Tests

Twelve Dynamic Cone Penetrometer Light (DPL) tests, designated DPL1 to DPL12, were

carried out at the approximate positions given in Figure 1, attached. The DPL tests were

advanced to refusal depths in the range 0.6m (DPL8 refers) to 3.6m (DPL7 refers).

The results of the DPL tests comprising plots of blow counts versus depth are given in

Appendix B.

7. INFERRED GEOLOGY AND ANTICIPATED SUBSURFACE

CONDITIONS

According to the 1:250 000 regional geological map of East Rand referenced “2628

Eastrand”, the general area of the site is underlain by quartzite and conglomerate of

Central Rand Group (Rjo). An extract of the above geological map is included below as

Plate 4.

Plate 4: Extract of Regional Geological Map of the Site (“2628 Eastrand”, by the Council for

Geoscience)

The materials observed from EGL on site at the positions profiled comprise a 100mm thick

layer of asphalt covering a thick sequence of fill material.

The following soil horizons in order of increasing depth have been observed in the

inspection pits excavated on site:

i. Fill Layer 1 - The fill layer can be described generally as slightly moist, light orange

brown to dark brown, medium dense to dense, coarse grained, clayey sandy

GRAVEL. This fill layer generally extends to approximate depths in the range 0.25m

(IP7 refers) to 0.4m (IP12 refers) below EGL.

ii. Fill Layer 2 - The fill layer can be described generally as slightly moist, reddish

orange brown, loose to medium dense, gravelly clayey SAND. This fill layer

!(Proposed Firestation Site

GISCOE

N

Key:

Pv – Vryheid Formation sandstone

Msy – Mokolian age syenite Ra – Feldspary porphyry of Klipriviers Group

Rj – Shale, quartzite, conglomerate of West Rand

Group

Rjo - Quarzite, conglomerate of Central Rand Group

Gold Mine

Gold Mine

6


generally extends to approximate depths in the range 0.6m (IP7 refers) to 2.7m (IP3

refers) below EGL.

iii. Fill Layer 3 - The fill layer can be described generally as slightly moist, yellowish

brown, loose, slightly gravelly clayey SAND. This fill layer generally extends to

approximate depths in the range 0.8m (IP8 refers) to 1.9m (IP5 refers) below EGL.

iv. Fill Layer 4 - The fill layer can be described generally as slightly moist, orange

brown, loose to medium dense becoming dense with depth, gravelly clayey SAND to

gravelly SANDY CLAY. This fill layer generally extends to approximate depths in

the range 1.2m (IP4 refers) to 2.7m (IP1 refers) below EGL.

v. Fill Layer 5 - The fill layer can be described generally as slightly moist to moist,

dark grey, medium dense, gravelly SAND. This fill layer generally extended to an

approximate depth of 1.0m (IP4 refers) below EGL.

vi. Fill Layer 6 - The fill layer can be described generally as slightly moist, pale red,

dense, slightly clayey GRAVEL with rock fragments. This fill layer generally

extended to an approximate depth of 1.7m (IP8 refers) below EGL.

vii. Fill Layer 7 - The fill layer can be described generally as slightly moist, light brown

to dark grey, medium dense, SANDY GRAVEL. This fill layer generally extended to

an approximate depth of 0.6m (IP11 refers) below EGL.

viii. Fill Layer 8 - The fill layer can be described generally as slightly moist, yellowish

brown, medium dense, silty SAND with brick paving and boulders. This fill layer

generally extended to an approximate depth of 0.6m (IP11 refers) below EGL.

Plates 5 to 8 below and overleaf provide an indication of the typical subsoil encountered on

site.

Plate 5: Fill soils encountered in IP1

7




8



8. GROUNDWATER

No groundwater seepage was observed in the inspection pits during this investigation.

Given the artificially raised nature of the site and the former lower ground elevations prior

to infilling to the present levels, there is the potential for a deep perched groundwater

condition associated with the former ground levels. This condition may be exacerbated by

climatic controls both during and after periods of rainfall.

Due cognisance of the potential for groundwater flows will need to be taken into account

during design and construction.

9. LABORATORY TESTING

The following laboratory tests were carried out on soil samples retrieved from the site:

Grading Analysis to 0,075mm sieve with Atterberg Limit Determinations;

Modified AASHTO tests;

California Bearing Ratio (CBR) tests;

Hydrometer Analysis; and

Falling head permeability testing.

The results of the laboratory tests are given in Appendix C and summarised in Table 1

overleaf.

9


Table 1: Summary of Laboratory Test Results: Indicators, Atterburg Limits, Moisture Contents, Permeability and Material Classification

IP

N

o

.

Depth

(m)

Description

Particle Size %

Atterberg

Limits % OMC

(%) GM

MDD

kg/m3

CBR Values Swell

%

Insitu

Moisture

Content

%

Permeability

k (m/s)

Material

Code &

Classification Clay Silt Sand Gravel LL PI LS

Compaction MDD %

90 93 95 97 98 100

IP1 0.1-0.3 Light orange brown, sandy

GRAVEL – Fill.

14 18 68 22 8 3.5 5.8 2.3 2196 17 37 62 90 108 155 0 - - A-2-4 (0)

G5

GC

IP1 0.3-0.7

Reddish orange

brown, clayey

SAND – Fill.

32 41 27 20 7 3.0 8.1 1.37 2097 12 24 35 39 41 46 0.1 - -

A-2-4(0)

G7

SM-SC

IP1 0.7-1.7 Yellowish brown, slightly clayey

SAND – Fill.

30 62 8 18 5 2.5 2088 8.1 2088 8.1 14 20 26 29 36 0 - - A-2-4(0)

G9

SM-SC

IP1 1.7-2.7

Orange brown,

gravelly clayey SAND – Fill.

12 17 47 24 24 8 4.0 - 1.34 - - - - - - - - 16.0 -

A-2-4(0)

SC *Low

IP2 0.3-2.0 Reddish orange brown, clayey

SAND – Fill.

14 20 59 7 21 8 3.0 - 0.93 - - - - - - - - 9.7 7.39x10-6 A-4(0)

SC

*Low

IP3 0.3-2.7

Reddish orange

brown, clayey

SAND – Fill.

42 33 25 24 9 4.0 11.9 1.18 2031 3.3 6.5 10 14 17 23 1.3 - -

A-4(1)

G10

SC

IP5 0.1-0.3 Light orange brown, sandy

GRAVEL – Fill.

22 28 50 23 10 4.0 6.3 1.9 2116 12 19 27 39 48 72 0.2 - - A-2-4(0)

G7

GC

IP6 0.3-1.7

Yellowish brown,

slightly clayey SAND – Fill.

- - - - - - - - - - - - - - - - - 1.60X10-4 -

IP8 1.6-1.7 Pale red, gravelly

SAND – Fill. 4 7 51 38 18 5 2.0 - 1.99 - - - - - - - - 3.0 -

A-1-b(0) SP

*Low

LL - Liquid Limit OMC - Optimum Moisture Content *Low - Expansiveness According to van der Merwe (1964)

PI - Plasticity Index LS - Linear Shrinkage G7 - Classification in Terms of TRH14 (1985)

A-4(1) - AASHTO Classification - - Not tested MDD - Maximum Dry Density

IMC - Insitu Moisture Content SC - Unified Classification GM - Grading Modulus

k - Co efficient of Permeability

10


10. DISCUSSION

10.1 Proposed Development

Information received by Geosure indicates that fire station and tower structures are

proposed for the site. Information supplied by the Engineers indicate that the fire station

and tower will have an approximate foundation load of 41 kN/m2 and 34kN/m

2,

respectively. No further structural details of the proposed building structures were made

available to Geosure at the time of preparation of this report.

Geosure will need to be given the opportunity to review the recommendations in this report

once detailed information regarding the design and layout of the proposed development is

available.

10.2 Undermining Activity beneath the Site

The geological map (refer to Plate 4) indicates at least three gold mines within close

proximity of the site.

Information supplied in electronic mail correspondence by the Administrative Department

of the Chamber of Mines on 21 February 2018, provides an indication that the Ferreira

Deep Gold Mines operates within the area. However, the Chamber of Mines has indicated

that the Council for Geoscience has the relevant information to confirm this activity.

Information regarding the current or abandoned mining activity and risks posed to the

environment was not available at the time of preparation of this report from the Council for

Geoscience.

10.3 Material Classification and Recommendations for Usage

The materials occurring on site have been classified in terms of the laboratory tests results.

The general assessment of these materials for use in the construction of fills has been based

on the results of the laboratory tests and the visual assessment made on site. The

characteristics of the materials and their suitability for use in construction is summarised in

Table 2 overleaf.

11


Table 2: Field Characteristics of Materials and Recommended Usage (BS 6031, 1981)

Material Type

and

Laboratory

Test Number

USC &

(TRH14)

Drainage

Characteristics

Sh

rin

ka

ge

or

Sw

elli

ng

Pro

per

ties

Va

lue

as

a

Ro

ad

Fo

un

da

tio

n

Co

effi

cien

t o

f

Bu

lkin

g %

Recommended Usage

FILL

Sandy

GRAVEL

(T07482 and

T07488)

GC

(G5 to G7)

Practically

impervious Very slight Excellent

10 to

20

Good subgrade material,

can be used as a select fill

layer, subject to further

laboratory testing during

construction.

Clayey SAND

(T07483 and

T07484)

SM (G7)

Fair to

practically

impervious

Almost

none to

medium

Fair to

good 5 to 15

Clayey SAND

(T07487) SC (G7)

Practically

impervious Very slight

Good to

excellent 5 to 15

Clayey SAND

(T07489) SP Excellent

Almost

none

Fair to

good 5 to 15

10.4 Excavation Characteristics

It is considered that the fill soils will be easily excavatable to final depths of the field tests

carried out. These materials classify as SOFT in terms of SANS 1200 DA criteria which

can easily be removed by hand tools or a TLB of flywheel power approximately 0,10kW

per millimetre of tined bucket width.

It is recommended that a contingency amount be allowed for Intermediate and Hard

excavations to address potential anomalies such as rubble, pipe services and foundation

remnants.

10.5 General Earthworks

Although extensive site earthworks are unlikely due to the relatively level nature of the

site, specifications are provided below in the event that levelling for platforms is carried

out.

All earthworks should be carried out in a manner to promote stable development of the

site. It is recommended that earthworks be carried out along the guidelines given in SANS

1200 (current version).

Where natural ground slopes are steeper than 1 vertical to 6 horizontal (≥ 9 degrees), the

fill must be benched into the slope. Benches should be 0.5m deep and 2.0m wide.

Placement of fill layers should be undertaken in layers not exceeding 200mm thick when

placed loose and compacted using suitable compaction plant to achieve 93% of Modified

AASHTO maximum dry density within 1-2 percent (wet/dry) of Optimum Moisture

Content (OMC).

Terraces should be graded to direct water away from the fill edges, and small earth bunds

should be constructed along the crests of fills, to prevent overtopping and erosion of fill

embankment slopes. These bunds should be a minimum 450mm wide and 300mm high.

12


Density control testing of placed fill material at regular intervals during fill construction as

part of process control construction is recommended as “best practice”.

Boulders larger than 200mm diameter or 2/3 of the layer thickness when loose should be

removed from the fill material as these could complicate the compaction works, and also

cause piping within fills. Furthermore, large boulders in fills could cause later problems

during construction of foundations.

Cut and fill slopes in soils may be formed to a batter of up to 1 vertical to 2 horizontal

(≤ 26 degrees) and to a height not greater than 1.5m where retaining walls are not

provided. Engineered fill slopes should be over constructed and thereafter trimmed back to

the required position.

Cut and fill heights greater than 1.5m would need to be inspected and approved by

geotechnical professional.

Sidewall collapse of excavations exceeding the above-mentioned configuration and not

battered back or shored is considered likely.

Workers should not enter any excavation deeper than 1.5 metres that is not shored or

battered back as specified above. Steeper batters can be considered but will be subject to

inspection and approval by a geotechnical professional on site during construction.

10.6 Founding Conditions

Due to loose consistencies inferred from DPL tests carried out these soils are considered to

be highly compressible. As such, the fill is considered to be unsuitable as founding

horizons for the use of shallow concrete foundations. Inferring from DPL tests and noting

the variation in founding conditions at the positions investigated, it is considered that the

option of shallow foundation solutions will necessitate ground improvement to

geotechnical specification to reduce the extent of compression related foundation

settlements.

10.7 Foundation Recommendations for the Proposed Fire Station

Information supplied to Geosure indicates that an approximate foundation load of 41kN/m2

is proposed for the site.

Accordingly, taking into account the likely proposed development and inferred founding

conditions, it is recommended that the following foundation types be considered:

i. Reinforced concrete strip footings on Improved Ground; and/or

ii. Reinforced Concrete Raft on Improved Ground.

13


10.7.1 Reinforced Concrete Strip Footings on Improved Ground

The option of strip footings on improved ground to support relatively light structural loads

is to allow for a limited undercut exercise as follows:

i. Undercut the soils to a depth of 1.6m below underside of EGL and to a plan area

equal to 1.5 times the least width of the foundation. If fill soils are encountered

beneath the foundation footprint, ensure that all fill is removed which may

necessitate increasing the depth of undercut, as verified during construction on site

by the geotechnical professional.

ii. If groundwater seepage is present, allow for the placement of a bed of coarse clean

(river type) sand for a layer thickness of at least 250mm vibrated with an

immersion type needle vibrator.

iii. Once the founding media at undercut levels have been certified satisfactory by the

geotechnical professional, backfill the excavation up to proposed founding level

with G6 or G5 quality material (TRH14 refers) imported to site, in loose layer

thicknesses of 200mm and compacted to a density of 95% Modified AASHTO

maximum dry density within 1-2 percent (wet/dry) of OMC.

iv. Provided the above is carried out, a maximum net allowable bearing pressure of

75kN/m2

is considered applicable for strip foundations.

v. Footings should not be placed more than 0.6m below final platform level to ensure

that footings are established on improved ground developed in line with the above

requirements to a thickness of at least 1.0m.

Strip foundations placed on improved ground developed in line with the above

specifications and net permissible foundation pressure design limit are likely to experience

total theoretical settlements in the approximate range 10mm to 15mm with differential

settlement taken as 50%.

10.7.2 Reinforced Concrete Raft on Improved Ground

It is considered that a raft foundation on improved ground will be equally suited to the

anticipated founding conditions for the proposed compact lightly loaded single storey

building structure. The raft should be designed to engineer’s detail to cater for potentially

active clay founding conditions associated with the residual clay.

The raft envisaged comprises a grid of reinforced concrete beams cast integrally with the

floor slab. By virtue of its stiffness, the raft can be designed to reduce the differential

heave movements of the supporting soil to a level that can be tolerated by the

superstructure. In general, it is uneconomical/impractical to construct a raft stiff enough to

allow the use of solid brickwork without ground treatment movement joints. Therefore, a

limited ground improvement exercise in conjunction with articulated brickwork to

engineer’s detail are recommended.

Allowance for the development of improved ground comprising well engineered select

inert gravel developed for an engineered thickness of 0.5m to underside of the raft soffit in

line with Section 10.7.1, paragraph i) through iii) above, will assist in limiting potential

14


differential settlements arising from applied structural loads and heave/shrinkage related

movements associated with any active profiles.

The raft should be constructed on a graded terrace to promote drainage. Excavations for

the raft beams are then formed into the terrace.

An approved damp proof plastic should be provided below the entire raft, and the slab and

beams should be cast as a single unit.

10.8 Foundation Recommendations for the Tower

Information supplied to Geosure indicates that an approximate foundation load of 34kN/m2

is proposed for the site.

The founding solutions as discussed in Section 10.7.1 and 10.7.2 above are also considered

applicable to this structure.

However, the foundation for the proposed tower structure will need to take into

consideration the effects of wind loading on the structure. Therefore, consideration would

need to be given to anchoring the tower into the subsurface. This would need to be carried

out to engineer’s detail.

In order to determine a suitable anchor horizon, a deeper geotechnical investigation would

need to be carried out.

10.9 Drainage

A critically important factor in the stable development of the site is the control and

removal of both surface and groundwater and wastewater from the site.

Earthworks and drainage measures should be designed in such a way as to prevent ponding

of, or high concentrations of, stormwater or groundwater anywhere on the site, both during

and after the development. Stormwater from roofed and paved surfaces is to be led off site

into the nearest municipal stormwater connection facility or approved disposal position.

Under no circumstances is disposal by soakaway for stormwater and wastewater to be

considered.

Any terrace(s) should be shaped to a gradient to prevent water ponding on the surface and

should be graded to direct water away from the fill edges and foundations.

The need for subsoil drains and dewatering will need to be assessed on site during

construction in consultation with the geotechnical professional.

15


11. SUPPLEMENTARY GEOTECHNICAL INVESTIGATION FOR THE

PROPOSED TOWER STRUCTURE ANCHORING POINTS

In order to gain adequate information on the likely subsurface conditions at the proposed

tower structure with respect to the design of suitable anchoring points, it is recommended

that a deeper geotechnical investigation be carried out. It is considered that allowance be

made for either a number of deep inspection pits formed by tracked excavator or the

drilling of rotary boreholes.

The proposed supplementary investigation should also make provision for evaluation and

comment regarding potential effects of the mining activity on the in-situ material on site.

12. SUMMARY AND OBSERVATIONS

i. The site at the position investigation comprises a thick sequence of fill material of

variable nature and quality down to final depths of the field tests.

ii. Groundwater seepage was not encountered in any of the inspection pits excavated on

site, nonetheless, there is a risk for an elevated groundwater conditions, exacerbated

during and after periods of rainfall.

iii. Considering that the site is underlain by a thick sequence of fill material of varying

consistency, the inferred founding character in these fill horizons on site is not

considered suitable for shallow foundations without allowance for ground

improvement.

iv. Founding options for the various structures are discussed in Sections 10.7 and 10.8.

In this regard, founding conditions on site suit reinforced concrete shallow strip

footings on improved ground and a raft on improved ground.

v. Information regarding the potential effect of existing mining activities beneath the

site is not known at the time of preparation of this report. Comment should be

allowed as part of a supplementary investigation regarding the potential effects of

mining activity in the general area of the site.

vi. All construction activities on site need to be carried out in accordance with the

current version of SANS 1200.

The ground conditions given in this report refer specifically to the field tests carried out on

site. It is therefore, quite possible that conditions at variance with those given in this report

could be encountered elsewhere on site during construction. It is therefore important that

Geosure be appointed to carry out periodic inspections during construction. Any change

from the anticipated ground conditions could then be taken into account to avoid

unnecessary expense. Allowance should also be made for conducting a supplementary

geotechnical investigation of deep founding requirements for the proposed Tower anchor

points and obtaining advice on mining activities in the general vicinity of the site.

16


13. REFERENCES

i. Brink, A., & Bruin, R. (2002). Guidelines for Soil and Rock Logging in South

Africa. Proceedings of the Geoterminology Workshop. South Africa: Association of

Engineering Geologists, South African Institute of Civil Engineering and South

African Institute for Engineering and Environmental Geologists.

ii. Google earth. (2018). AfriGIS (Pty) Ltd. Retrieved 20 02, 2018, from Google earth:

www.googlearth.com

iii. South African Bureau of Standards. (1990). Standard Specification for Civil

Engineering Construction, D: Earthworks. South Africa: South African Bureau of

Standards.

iv. British Standards (1981). Codes of Practice for Earthworks.

v. Electronic mail corespondance from Chamber of Mines on 21 February 2018.

APPENDIX A

●●●●●●●●●●●●●●●●●●●●●

INSPECTION PIT PROFILES

●●●●●●●●●●●●●●●●●●●●●●●●●●●●

Geotechnical, Environmental & Groundwater Engineering Pile Integrity Testing & Civil Engineering Laboratory P O Box 1461, Westville, 3630, South Africa Tel: (031) 266-0458 Fax: 086 689-5506 email: geosure@ iafrica.com www.geosure.co.za

0.10--0.30

0.30--0.70

0.70--1.10

1.70--2.70

Johannesburg Development AgencyProposed New CentralFire Station Project, Johannesburg,Gauteng

HOLE No: IP1Sheet 1 of 1


JOB NUMBER: 015-18JOB NUMBER: 015-18

0.10

0.00

0.30

0.70

1.10

2.70

Asphalt.

Slightly moist, light orange brown to dark brown, medium dense to dense, coarse grained,sandy GRAVEL. FILL. (G5)

Slightly moist, reddish orange brown, loose to medium dense, clayey SAND. FILL. (G7)

Moist, yellowish brown, loose, slightly clayey SAND. FILL. (G9)

Slightly moist, orange brown, loose, gravelly slightly clayey SAND with dolerite/sandstonerock fragments. FILL.

Scale1:25

NOTES

1) No groundwater seepage observed.

2) Samples taken at:S1 0,10--0,30 (2 x Bulk)S2 0,30--0,70 (2 x Bulk)S3 0,70--1,10 (2 x BulkS4 1,70--2,70 (Ind)

3) Hand augered from 1,20m.

4) Refusal on hard material at 2,70m.

5) Refusal depth at 2,70m.

CONTRACTOR :MACHINE :

DRILLED BY :PROFILED BY :

TYPE SET BY :SETUP FILE :

-

N.Govender

K.NaidooSTANDARD.SET

INCLINATION :DIAM :DATE :DATE :

DATE :TEXT :

--30 Jan to 01 Feb 201830 Jan to 01 Feb 2018

23/02/18 11:43..C:\LOGS\PITS.TXT

ELEVATION :X-COORD :Y-COORD :

1743m-26.2099328.04352

dotPLOT 6008 PBpD069 Geosure (Pty) Ltd

HOLE No: IP1HOLE No: IP1


0.30--2.00





0.10

0.00

0.30

2.00

Asphalt.

Slightly moist, light orange brown to dark brown, medium dense to dense, coarse grained,sandy GRAVEL. FILL.

Slightly moist, reddish orange brown, loose to medium dense, clayey SAND. FILL.

Scale1:25

NOTES


2) Sample taken at:S1 0,30--2,00 (Ind)


4) Refusal hard subsurface at 2,70m.





-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1742m-26.2096028.04349




0.30--2.700.30--2.70





0.10

0.00

0.30

2.70

Asphalt.


Slightly moist, reddish orange brown, loose to medium dense, clayey SAND. FILL. (G10)

Scale1:25

NOTES


2) Samples taken at:S1 0,30--2,70 (Ind)S2 0,30--2,70 (2 x Bulk)







-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1735m-26.2097728.04382




1.50--2.60





0.10

0.00

0.30

0.80

1.00

1.50

2.60

Asphalt.



Slightly moist, dark grey, medium dense, gravelly SAND. FILL.

Slightly moist, orange brown, loose, gravelly slightly clayey SAND with dolerite/sandstonerock fragments. FILL.

Slightly moist, light orange brown, medium dense, gravely SAND with sandstonefragments. FILL.

Scale1:25

NOTES









-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1740m-26.2098628.04393




0.10--0.30





0.10

0.00

0.30

0.70

1.90

Asphalt.

Slightly moist, light orange brown to dark brown, medium dense to dense, coarse grained,sandy GRAVEL. FILL. (G7)


Moist, yellowish brown, loose to medium dense, slightly clayey SAND. FILL.

Scale1:25

NOTES


2) Sample taken at:S1 0,10--0,30 (2 x Bulk)

3) Hand auger from 1,20m.






-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1736m-26.2100028.04374




0.30--1.70





0.10

0.00

0.30

1.70

2.00

Asphalt.



Slightly moist, orange brown, medium dense, gravelly slightly clayey SAND withdolerite/sandstone rock fragments. FILL.

Scale1:25

NOTES








-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1734m-26.2101728.04358








0.10

0.00

0.25

0.60

1.00

1.80

2.60

Asphalt.





Slightly moist, orange brown, loose to medium dense, gravelly slightly clayey SAND withdolerite/sandstone rock fragments. FILL.

Scale1:25

NOTES







-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1744m-26.2098128.04364




1.60--1.70





0.30

0.00

0.70

0.80

1.60

1.70

Slightly moist, light orange brown, loose to medium dense, slightly clayey SAND with roots.FILL.



Slightly moist, orange brown, loose to medium dense, gravelly slightly clayey SAND withdolerite/sandstone rock fragments. FILL.

Slightly moist, pale red, dense, gravelly SAND to sandy GRAVEL with sandstone/quartzitefragments. FILL.

Scale1:25

NOTES








-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1739m-26.2095228.04384








0.10

0.00

0.35

1.70

Asphalt.



Scale1:25

NOTES







-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1727m-26.2095028.04412








0.10

0.00

0.40

1.00

2.70

Asphalt.



Slightly moist, light orange brown, medium dense, gravely SAND with sandstonefragments. FILL.

Scale1:25

NOTES








-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1742m-26.2101328.04400








0.10

0.00

0.60

1.00

Asphalt.

Slightly moist, light brown to dark grey, medium dense, SANDY GRAVEL. FILL.

Slightly moist, yellowish brown, medium dense, silty SAND with brick paving and boulders.FILL.

Scale1:25

NOTES


2) Refusal depth at 1,00m on concrete slab.




-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1745m-26.2104528.04334








0.10

0.00

0.40

0.80

1.50

Asphalt.




Scale1:25

NOTES








-

N.Govender



DATE :TEXT :


23/02/18 11:43..C:\LOGS\PITS.TXT


1743m-26.2104528.04394



APPENDIX B

●●●●●●●●●●●●●●●●●●●●●

RESULTS OF DYNAMIC CONE

PENETROMETER LIGHT (DPL)

TESTS

●●●●●●●●●●●●●●●●●●●●●●●●●●●●

GEOSURE (PTY) LTD.Geotechnical Engineering Consultants

Tel: 0861 436 7873 Fax: 086 689 5506 Email: [email protected]

Client: Johannesburg Development Agency Ref.No. 015-18

Project: Proposed New Central Fire Station Project Date: 30/01/18-01/02/2018

Section: Johannesburg, Gauteng Operator: N.Govender

L i g h t D y n a m i c P e n e t r o m e t e r P r o b e --------------- T e s t N o. DPL 1

THE INSITU STRENGTH DEPENDS ON SOIL MOISTURE CONTENT AND GRAIN STRUCTURE WHICH HAVE NOT BEEN ASSESSED AND

MAY CHANGE. THE VALUES GIVEN ARE THEREFORE INDICATIVE ONLY AND SHOULD BE VERIFIED BY TEST OR OBSERVATION

Hammer: 10kg falling 550mm

Cone: 25mm diameter with 60 degree apex angel

Depth Blows Inferred Rods: 16mm diameter, 22mm diameter couplings

metres per 300mm Consistency

0

0.3 29 Med.Dense 34 deg



1.2 9 Loose <30 deg

1.5 7 Loose <30 deg

1.8 9 Loose <30 deg

2.1 12 Loose <30 deg

2.4 45 Dense 36 deg

Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm

\\GEOSURE-SERVER\Geosure\2018\015-18 (New Central Fire Station JHB)\DPLs\DPL1













0



0.9 8 Loose <30 deg

1.2 2 Very Loose <29 deg




2.4 8 Loose <30 deg


3 25 Med.Dense 33 deg

Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0

0.3 -







Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0







2.1 43 Dense 36 deg


Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0







Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0






1.8 53 Dense 37 deg

2.1 61 Dense 37 deg

Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0



0.9 8 Loose <30 deg

1.2 8 Loose <30 deg

1.5 8 Loose <30 deg

1.8 9 Loose <30 deg


2.4 9 Loose <30 deg


3 35 Med.Dense 35 deg

3.3 42 Dense 36 deg

3.6 45 Dense 36 deg

Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0



Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0

0.3 60 Dense 37 deg

0.6 46 Dense 36 deg




1.8 9 Loose <30 deg


Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0








Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0







Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm














0

0.3 -




Refusal

Insitu Shear

Strength

-15

-14.4

-13.8

-13.2

-12.6

-12

-11.4

-10.8

-10.2

-9.6

-9

-8.4

-7.8

-7.2

-6.6

-6

-5.4

-4.8

-4.2

-3.6

-3

-2.4

-1.8

-1.2

-0.6

0

0 10 20 30 40 50 60 70 80 90 100

Dep

th (

m)

Blows per 300mm


APPENDIX C

●●●●●●●●●●●●●●●●●●●●●

LABORATORY TEST RESULTS

●●●●●●●●●●●●●●●●●●●●●●●●●●●●

of 16

CLIENT : Geosure (Pty) Ltd PHYSICAL ADDRESS : 122 Intersite Avenue, Springfield Park, Umgeni Durban, 4001 ATTENTION : Mr D. Naidoo PROJECT : Central JHB Firestation

TEST REPORT REFERENCE NUMBER: 34356 Dear Sir/Madam, Enclosed herewith, please find the original reports pertaining to the above-mentioned project. Date Received 07.02.2018 Date Tested 08.02.2018 to 19.02.2018

Sample Location Refer to Report

Sampling Method N/A

Sample Condition Moist

Sampling Environmental Condition N/A

Sampler(s) Name Client

Total Number of Pages 16

Test Carried Out TMH1 Method A1 & A5

TMH1 Method C3

TMH1 Method A2, A3, A4

TMH1 Method C4a

TMH1 Method A7

TMH1 Method B6

TMH1 Method A8

Hydrometer Analysis - ASTM D422

TMH1 Method A10(b) SANS 5863

TMH1 Method A13T + A14app SANS 5862-1

TMH1 Method A15d SANS 5860, 5861-1, 5861-2, 5861-3

TMH1 Method A13T + A16T TMH1 Method B9

- Tick denotes tests that were carried out. We would like to take this opportunity of thanking you for your continued support. Should you have any queries please do not hesitate to contact me. Yours faithfully ___________________ Technical Signatory, Bradley Hariram for Geosure (Pty) Ltd. This report may not be reproduced except in full, without written permission from Geosure (Pty) Ltd. While every care is taken to ensure the correctness of all tests and reports, neither Geosure (Pty) Ltd or its employees shall be liable in any way whatsoever for any error made in the execution or reporting of tests or any erroneous conclusions drawn there from or any consequence thereof. This report relates only to the sample/s tested. Head Office 122 Intersite Avenue, Umgeni Business Park, Durban 4091, South Africa PO Box 1461, Westville, 3630, South Africa Tel.: +27 (0)861 GEOSURE / 0861 436 7873 Fax: +27 (0)86 689 5506 Mobile: +27 (0)82 784 0544 E-mail: [email protected]

Civil Engineering Laboratory 122 Intersite Avenue, Umgeni Business Park, Durban, 4091, South Africa PO Box 1461, Westville, 3630, South Africa Tel: 031 701 9732 Fax: +27 (0) 86 684 9785 Mobile: 072 870 2621 E-mail: [email protected]

Gauteng Branch P. O. Box 32381, Kyalami 1684 Tel.: 0861 GEOSURE / 0861 436 7873 Fax: 086 689 8327 Mobile: 083 377 6559 Email: [email protected]




User

New Stamp

LABORATORY AND HEAD OFFICE ADDRESS: 122 Intersite Avenue, Umgeni Business Park, Durban, 4091

LABORATORY CONTACT INFO.: Tel.: +27(0) 31 701 9732 Fax: 086 684 9785Mobile: +27(0) 72 870 2621 e-mail: [email protected]

HEAD OFFICE CONTACT INFO.: Tel.: +27(0) 31 266 0458 Fax: 086 689 5506Mobile: +27(0) 82 784 0544 e-mail:[email protected]

WEBSITE: www.geosure.co.za

Client : Geosure (Pty) Ltd Our Ref. : 34356Project : Your Ref. : 015-18

Date Tested : 08.02.2018 to 19.02.2018Attention : Mr D. Naidoo Date Reported : 19.02.2018

T07485 T07486 T07489IP 1 IP 2 IP 8

Layer 5 Layer 3 Layer 51.7-2.7 0.3-2.0 1.6-1.7

75.0 mm 100 100 10063.0 mm 100 100 10053.0 mm 100 100 10037.5 mm 100 100 10026.5 mm 100 100 9619.0 mm 100 97 9313.2 mm 100 97 834.75 mm 92 95 69

Sieve Analysis ( Wet Preparation ) - TMH1 - Method A1 (a) - Percent Passing Sieve Size

Sample No.

Central JHB Firestation

Orange brown gravelly slightly

clayey SAND. Fill

Pale red gravelly SAND. Fill

Reddish orange brown clayey SAND.

Fill

% P

assi

ngReg.No.: 92/03145/07

Field No.Position in FieldDepth (m)

Material Description

2.00 mm 76 93 620.425 mm 57 76 270.075 mm 33 38 12

0.060 mm 29 34 110.050 mm 26 32 110.040 mm 23 29 100.026 mm 19 26 100.015 mm 16 22 80.010 mm 15 21 80.0074 mm 15 20 70.005 mm 14 18 50.002 mm 12 14 40.0015 mm 11 13 3

% 25 18 56

% 10 14 13% 9 14 7% 13 13 5% 43 41 19

1.34 0.93 1.99

Liquid Limit % 24 21 18Plasticity Index % 8 8 5Linear Shrinkage % 4.0 3.0 2.0AASHTO Classification (Group Index)* A-2-4 (0) A-4 (0) A-1-b (0)

SC SC SP-??Moisture Content % 16.0 9.7 3.0Remarks: Date Received:07.02.2018

This report relates only to sample(s) received. This report shall not be reproduced, except in full, without the prior consent of GEOSURE (PTY) LTD.

Medium Fine SandFine Fine Sand

Version 06/09/2016

*Opinions expressed herein fall outside the scope of SANAS accreditation.

Coarse Fine SandCoarse Sand

Mechanical analysis - TMH1 - Method A5 - Percent of Soil Mortar (<2 mm) for Grain Size range

% P

assi

ng

Hydrometer Analysis - ASTM - D422 - Percent Passing Particle Diameter (<0.425mm)

Sampled by Client.

Atterberg Limits - TMH1 - Methods A2, A3, A4 (<0.425mm)

Page 2 of 16

Unified Classification*

Silt & ClayGrading Modulus


mailto:e-mail:[email protected]

http://www.geosure.co.za





Client : Geosure (Pty) Ltd Job No. :Project : Central JHB Firestation Your Ref.No. :

Date Tested :Attention : Mr D. Naidoo Date Reported :

Sample Number : T07485 : IP 1

Sample Description : Orange brown gravelly slightly clayey SAND. FillEquivalent PI : 5 : 12

Reg.No.: 92/03145/07

POTENTIAL EXPANSIVENESS GRAPH

34356015-1808.02.2018 to 19.02.201819.02.2018

Clay fraction of whole sample (% <2µ)

Field No.

152025303540455055606570

Equi

vale

nt P

I

Medium

HighVery High


Version 24/03/2016 Page 3 of 16

PARTICLE SIZE DISTRIBUTION CHART

05

1015

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

Clay fraction of whole sample ( % <2µ )

0

10

20

30

40

50

60

70

80

90

100

110

0.000 0.001 0.010 0.100 1.000 10.000 100.000

% F

iner

Tha

n

LowMedium

FINE COARSE FINE MEDIUM COARSEMEDIUM FINE MEDIUM COARSE

CLAY FRACTION SILT FRACTION SAND FRACTION GRAVEL FRACTION











Sample Description : Reddish orange brown clayey SAND. FillEquivalent PI : 6 : 14

Reg.No.: 92/03145/07


34356015-1808.02.2018 to 19.02.201819.02.2018


Field No.

25303540455055606570

Equi

vale

nt P

I

HighVery High




05

10152025

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

Equi

vale

nt P

I


0

10

20

30

40

50

60

70

80

90

100

110

0.000 0.001 0.010 0.100 1.000 10.000 100.000

% F

iner

Tha

n

LowMedium













Sample Description : Pale red gravelly SAND. FillEquivalent PI : 1 : 4

Reg.No.: 92/03145/07

Field No.



25303540455055606570

Equi

vale

nt P

I

HighVery High




05

10152025

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

Equi

vale

nt P

I


0

10

20

30

40

50

60

70

80

90

100

110

0.000 0.001 0.010 0.100 1.000 10.000 100.000

% F

iner

Tha

n

LowMedium






LABORATORY: Reg. No. : 92/03145/07 HEAD OFFICE:122 Intersite Avenue, Umgeni Business Park, Durban, 4091 122 Intersite Avenue, Umgeni Business Park,P.O. Box 1461, Westville 3630 Durban, 4091, KwaZulu Natal, South Africa.Mobile: +27(0)72 870 2621 Fax: 086 684 9785 Tel: +27 (0)31 266 0458 Fax: 086 689 5506Tel.: +27 (0)31 701 9732 email: [email protected] email: [email protected] www.geosure.co.za

Client : Your Ref No. : 015-18Project : Our Ref No. : 34356Attention : Date Reported : 19/02/2018

Sample_No1 Sample_No2 Sample_No3 Sample_No4 Sample_No5

Sample No. T07482 T07483 T07484 T07487 T07488Field No. IP 1 IP 1 IP 1 IP 3 IP 5Position Layer 2 Layer 3 Layer 4 Layer 3 Layer 2Depth ( m ) 0.1-0.3 0.3-0.7 0.7-1.7 0.3-2.7 0.1-0.3

Material DescriptionLight orange brown sandy GRAVEL. Fill


Fill

Yellowish brown slightly clayey SAND.

Fill


Fill

Light orange brown sandy GRAVEL. Fill

75.0063.0053.00 100 10037.50 84 92 100 10026.50 73 92 94 9619.00 61 86 100 88 8013.20 48 82 99 86 684.750 37 79 97 81 572.000 32 73 92 75 500.425 25 58 71 65 39

Central JHB FirestationGeosure (Pty) Ltd

Mr D. Naidoo

Test Report

Sieve Analysis ( Wet Preparation ) TMH1 - Method A1 (a) - Percent Passing Sieve Size

Siev

e A

pert

ure

(mm

)

0.425 25 58 71 65 390.075 14 32 30 42 22

Grading Modulus 2.30 1.37 1.07 1.18 1.90

Coarse Sand 2.000 - 0.425 23 21 23 13 23Coarse-Fine Sand 0.425 - 0.250 12 13 15 8 12Medium-Fine Sand 0.250 - 0.150 11 11 15 10 11Fine-Fine Sand 0.150 - 0.075 11 12 15 13 11Silt and Clay < 0.075 42 44 32 56 43

Liquid Limit % or symbol 22 20 18 24 23Plasticity Index % or symbol 8 7 5 9 10Linear Shrinkage % 3.5 3.0 2.5 4.0 4.0

Maximum Dry Density (kg/m³) 2196 2097 2088 2031 2116Optimum moisture content (%) 5.8 8.1 8.1 11.9 6.3

CBR @100% Compaction % 155 46 36 23 72CBR @ 98% Compaction % 108 41 29 17 48CBR @ 97% Compaction % 90 39 26 14 39CBR @ 95% Compaction % 62 35 20 10 27CBR @ 93% Compaction % 37 24 14 6.5 19CBR @ 90% Compaction % 17 12 8.1 3.3 12Swell @100% Compaction % 0.0 0.1 0.0 1.3 0.2TRH 14 Classification (1985)** G5 G7 G9 G10 G7AASHTO Classification (Group Index)** A-2-4 (0) A-2-4 (0) A-2-4 (0) A-4 (1) A-2-4 (0)Unified Classification ** GC SM-SC SM-SC SC GCThis report relates only to sample(s) received. This report shall not be reproduced, except in full, without the prior consent of GEOSURE (Pty) Ltd.

*Subject to further testing as required by TRH14.Remarks: *Subject to further testing as required by TRH14.

** Opinions and interpretations expressed herein are outside the scope of SANAS accreditationVersion 4.02 - 24 March 2014

Mechanical analysis - TMH1 - Method A5 - Percent of Soil Mortar (<2 mm) for Grain Size range

Atterberg Limits TMH 1 - Methods A2, A3, A4 on <0.425 mm fraction

Maximum Dry Density and Optimum Moisture Content - TMH1 - Method A7

California Bearing Ratio - TMH1 - Method A8

ReportT07482.xls Page 6 of 16





Client : Geosure (Pty) Ltd Your Ref No.:Project : Central JHB Firestation Our Ref No. :Attention : Mr D. Naidoo Date Reported :

0.1 140.2 170.3 210.4 25

2 324.8 3713 4819 6127 7338 8453 1006375

Grading Curve for Sample T07482 – TMH1 Method A1 (a)

015-183435619/02/2018

60

70

80

90

100

% P

assi

ng

Thick Red Line is the Grading Curve (TRH 14 Classification = G5)Sieve Aperture Size 0.075 0.150 0.250 0.425 2.00 4.75 13.2 19.0 26.5 37.5 53 63 75Percentage Passing 14% 17% 21% 25% 32% 37% 48% 61% 73% 84% 100%

0

10

20

30

40

50

0.001 0.01 0.1 1 10 100

% P

assi

ng

Grain Size (mm)







0.1 320.2 410.3 490.4 58

2 734.8 7913 8219 8627 9238 9253 1006375


015-183435619/02/2018

60

70

80

90

100

% P

assi

ng

Thick Red Line is the Grading Curve (TRH 14 Classification = G7)Sieve Aperture Size 0.075 0.150 0.250 0.425 2.00 4.75 13.2 19.0 26.5 37.5 53 63 75Percentage Passing 32% 41% 49% 58% 73% 79% 82% 86% 92% 92% 100%

0

10

20

30

40

50

0.001 0.01 0.1 1 10 100

% P

assi

ng

Grain Size (mm)







0.1 300.2 430.3 570.4 71

2 924.8 9713 9919 1002738536375


015-183435619/02/2018

60

70

80

90

100

% P

assi

ng

Thick Red Line is the Grading Curve (TRH 14 Classification = G9)Sieve Aperture Size 0.075 0.150 0.250 0.425 2.00 4.75 13.2 19.0 26.5 37.5 53 63 75Percentage Passing 30% 43% 57% 71% 92% 97% 99% 100%

0

10

20

30

40

50

0.001 0.01 0.1 1 10 100

% P

assi

ng

Grain Size (mm)







0.1 420.2 510.3 590.4 65

2 754.8 8113 8619 8827 9438 100536375


015-183435619/02/2018

60

70

80

90

100

% P

assi

ng

Thick Red Line is the Grading Curve (TRH 14 Classification = G10)Sieve Aperture Size 0.075 0.150 0.250 0.425 2.00 4.75 13.2 19.0 26.5 37.5 53 63 75Percentage Passing 42% 51% 59% 65% 75% 81% 86% 88% 94% 100%

0

10

20

30

40

50

0.001 0.01 0.1 1 10 100

% P

assi

ng

Grain Size (mm)







0.1 220.2 270.3 330.4 39

2 504.8 5713 6819 8027 9638 100536375


015-183435619/02/2018

60

70

80

90

100

% P

assi

ng

Thick Red Line is the Grading Curve (TRH 14 Classification = G7)Sieve Aperture Size 0.075 0.150 0.250 0.425 2.00 4.75 13.2 19.0 26.5 37.5 53 63 75Percentage Passing 22% 27% 33% 39% 50% 57% 68% 80% 96% 100%

0

10

20

30

40

50

0.001 0.01 0.1 1 10 100

% P

assi

ng

Grain Size (mm)






Client : Geosure (Pty) Ltd Your Ref No. : 015-18Project : Central JHB Firestation Our Ref No. : 34356Attention : Mr D. Naidoo Date Reported

Sample No. : T07482 Field No. : IP 1Depth (m) : 0.1-0.3

Natural/Stabilised : Natural Origin : Layer 2Material Description Compaction Effort : Mod AASHTO

Maximum Dry Density (kg/m³) 2196 5.8

Plotted Values:Moisture (%) 3.9 4.9 5.9 6.9 7.9Dry Density (kg/m³) 2139 2159 2196 2142 2115

: 19.02.2018

Moisture/Density Relationship (TMH1: Method A7)

Optimum Moisture Content (%)

: Lt.Or.Br.sandy GRAVEL. Fill

2220

Remarks:

Ver 4.01 - 13 March 2014

This report relates only to sample(s) received. This report shall not be reproduced, except in full, without the prior consent of GEOSURE (Pty) Ltd.

Page 12 of 16

2100

2120

2140

2160

2180

2200

3 4 5 6 7 8 9

Dry

Dens

ity (k

g/m

³)

Moisture (%)










: 19.02.2018



: Red.Or.Br.clayey SAND. Fill

2150

Remarks:

Ver 4.01 - 13 March 2014


Page 13 of 16

1900

1950

2000

2050

2100

3 4 5 6 7 8 9 10 11 12 13

Dry

Dens

ity (k

g/m

³)

Moisture (%)










: 19.02.2018



: Yell.Br.Sl.clayey SAND. Fill

2150

Remarks:

Ver 4.01 - 13 March 2014


Page 14 of 16

1800

1850

1900

1950

2000

2050

2100

4 5 6 7 8 9 10 11 12 13

Dry

Dens

ity (k

g/m

³)

Moisture (%)










: 19.02.2018



: Red.Or.Br.clayey SAND. Fill

2050

Remarks:

Ver 4.01 - 13 March 2014


Page 15 of 16

1800

1850

1900

1950

2000

7 8 9 10 11 12 13 14 15 16

Dry

Dens

ity (k

g/m

³)

Moisture (%)










: 19.02.2018



: Lt.Or.Br.sandy GRAVEL. Fill

2150

Remarks:

Ver 4.01 - 13 March 2014


Page 16 of 16

1900

1950

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2050

2100

2 3 4 5 6 7 8 9 10 11

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Dens

ity (k

g/m

³)

Moisture (%)




FIGURE 1

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SITE PLAN

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