Report to Malani Padayachee & Associates (Pty) Ltd on the … · 2019-10-24 · Geosure Gauteng...

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LEVEL 1 BEE CONTRIBUTOR

Report to Malani Padayachee & Associates (Pty) Ltd on the

Results of a Deeper Geotechnical Investigation for the

Proposed Tower Structure for the 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: JHB015-19.R01

Revision 0

Dated: 27 June 2019

Geosure Gauteng (Pty) Ltd www.geosure.co.za JHB015-19.R01.docx

Report to Malani Padayachee & Associates (Pty) Ltd

on the Results of a Deeper Geotechnical

Investigation for the Proposed Tower Structure for

the Central Fire station, Johannesburg, Gauteng

Reference : JHB015-19.R01

Revision 0

Dated : 27 June 2019

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

SANAS Accredited Soil and Rock Laboratory

Head Office & Laboratory

122 Intersite Avenue, Umgeni Business Park, Durban, 4001, South Africa

PO Box 1461, Westville, 3630

Head Office

Tel.: 031 266 0458 (International +2731 266 0458)

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Cell: +27 (0)82 784 0544

E-mail: [email protected]

Civil Engineering Laboratory Gauteng Branch

Tel: 031 701 9732 Postnet Suite 457, Private Bag X29,

Gallo Manor, 2052

Fax: 086 684 9785 Tel: 0861 GEOSURE (4367873)

Cell: 072 870 2621 Cell: +27 (0)82 557 0473

E-mail: [email protected] Fax: +27 086 689 8327


www.geosure.co.za

mailto:[email protected]


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Document Control Record

Document prepared by:

Geosure Gauteng (Pty) Ltd

44 Andries Street

Wynberg

Sandton

2019

Tel: 0861 436 7873

Fax: 086 689 5506


Website: www.geosure.co.za

A person using Geosure Gauteng (Pty) Ltd documents must take note of the following:

a) Electronic copies to be checked against original hard copy version to ensure accuracy.

b) Using the documents or data for any purpose not agreed to in writing with Geosure

(Pty) Ltd is prohibited.

Document Control

Report Title Report to Malani Padayachee & Associates (Pty) Ltd on the Results of a

Deeper Geotechnical Investigation for the Proposed Tower Structure for


Report Reference JHB015-19.R01 Responsible Person Mr D. Gertzen

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

E East

EGL existing ground level

Geosure Geosure Gauteng (Pty) Ltd

GM grading modulus

IMC insitu moisture content

JDA Johannesburg Development Agency

JMPD Johannesburg Metropolitan Police Department

kN/m2 kilonewtons per metre square

LL liquid limit

LS linear shrinkage

m metre (s)

MDD maximum dry density

mm millimetre

MPA Malani Padayachee & Associates

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)


Report to Malani Padayachee & Associates (Pty) Ltd on the

Results of a Deeper Geotechnical Investigation for the Proposed

Tower Structure for the Central Fire station, Johannesburg,

Gauteng

Reference: JHB015-19.R01 Revision 1 Date: 27 June 2019

TABLE OF CONTENTS

1. INTRODUCTION AND TERMS OF REFERENCE .......................................................................... 6

2. SCOPE OF REPORT .............................................................................................................................. 6

3. GUIDELINES FOR METHODOLOGY OF INVESTIGATION ....................................................... 6

4. INFORMATION USED .......................................................................................................................... 7

5. SITE DESCRIPTION ............................................................................................................................. 7

6. FIELDWORK .......................................................................................................................................... 9

6.1 GEOTECHNICAL BOREHOLE ............................................................................................................................. 9

7. INFERRED GEOLOGY AND ANTICIPATED SUBSURFACE CONDITIONS ...........................10

8. GROUNDWATER .................................................................................................................................12

9. DISCUSSION ..........................................................................................................................................12

9.1 PROPOSED DEVELOPMENT ..............................................................................................................................12 9.2 MINING ACTIVITY BENEATH THE SITE ...........................................................................................................12 9.3 GLOBAL STABILITY ........................................................................................................................................14 9.4 TRENCHABILITY ASSESSMENT ........................................................................................................................14 9.5 EARTHWORKS .................................................................................................................................................14 9.6 FOUNDING CONDITIONS ..................................................................................................................................16 9.7 FOUNDATION RECOMMENDATIONS FOR THE PROPOSED FIRE STATION ..........................................................16

9.7.1 Pad/Strip Footings on Rock .....................................................................................................................16 9.7.2 Piled Foundation .....................................................................................................................................16 9.8 DRAINAGE ......................................................................................................................................................18

10. SUMMARY AND OBSERVATIONS ...................................................................................................18

11. REFERENCES .......................................................................................................................................18

Appendix A: Borehole Profile

6


Report to Malani Padayachee & Associates (Pty) Ltd on the Results of a

Deeper Geotechnical Investigation for the Proposed Tower Structure for


Reference: JHB015-19.R01 Revision 0 Date: 27 June 2019

1. INTRODUCTION AND TERMS OF REFERENCE

Geosure was appointed by Johannesburg Development Agency (Pty) Ltd (JDA) in

January 2018 to carry out a geotechnical investigation for the construction of the New

Central Fire Station. A shallow geotechnical investigation was carried out which entailed

inspection pits being excavated by hand to a maximum depth of 1.5m below existing

ground level (EGL). A recommendation given in the shallow geotechnical report was to

drill an additional borehole at the proposed elevated tower site to confirm rock levels for

the proposed foundations. The report arising from the above investigation is dated 31st July

2018 and titled “Report to Johannesburg Development Agency (Pty) Ltd on the Results of

a Shallow Geotechnical Investigation for the Proposed Central Fire station,

Johannesburg, Gauteng” and reference 015-18.R01. Revision 1.

In May 2019, JDA requested Geosure to provide a cost estimate to carry out the

supplementary investigation. Geosure issued a proposal and cost estimate under cover of a

letter referenced p339-19 (Central fire Station)/ng and dated 21 May 2019.

Subsequently, Geosure was authorised by Malani Padayachee & Associates (Pty) Ltd

(MPA), hereafter referred to as “the Client”, in a letter of appointment dated 30 May 2019

to proceed with the investigation as proposed.

2. SCOPE OF REPORT

This report details the results of a deeper geotechnical investigation for the proposed tower

structure for the 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, and comment regarding any mining

activity beneath the site, are made.

3. GUIDELINES FOR METHODOLOGY OF 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

7


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 MPA and their professional team for the purpose

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

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;

iii. Digital copy of a underground mine survey drawing, titled “Underground Mine

Plan”, prepared by Village Main Reef G.M. Co. (1934) Ltd to a scale of 1:2000.

(Information supplied by JDA).

iv. 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.

8


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

9


Plate 3: View of the site from the west

6. FIELDWORK

The fieldwork for the investigation was carried out over the period 10 June 2019 to

14 June 2019 and comprised the drilling of a single borehole.

6.1 Geotechnical Borehole

A single geotechnical borehole, designated BH1 was carried out by Roelf Fourie

Geotechnical Services at the approximate positions given in Plate 4. The borehole was

advanced through the subsurface using an NWD4 core barrel to a final depth of 10.5m

below EGL.

The latitude and longitude coordinates as well as the approximate elevations and

approximate final depths of the borehole is given in Table 1 below.

Table 1: Latitude and Longitude Coordinates, Approximate Elevation and Final

Depths of borehole

BH No. Latitude Longitude

*Approximate

Elevation

above MSL (m)

Final Depth

below EGL

(m)

Final

Elevation

above MSL

(m)

BH1 26.21044 S 28.04347 1745 10.5 1734.5

*- Elevations measured using a hand held GPS device

The borehole was profiled using the South African Geoterminology Guidelines (Brink &

Bruin, 2002). Copies of the detailed borehole profiles are given in Appendix A.

10


Plate 4: Location of the borehole drilled on site

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 5.

Plate 5: Extract of Regional Geological Map of the Site (“2628 Eastrand”, by the Council for

Geoscience)

!(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

N

11


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

inspection pits excavated on site:

i. Unit 1: Fill Layer 1 - The fill layer can be described generally as dark grey, dense,

coarse, GRAVEL. This fill layer generally extended to an approximate depth of 0.5m

below EGL.

ii. Unit 2: Fill Layer 2 - The fill layer can be described generally as Pale brown to dark

grey, soft, fine grained, sandy SILT. This fill layer generally extended below the fill

of Unit 1 to an approximate depth of 1.0m below EGL.

iii. Unit 3: Residual Sandstone - The fill layer can be described generally as reddish

orange, medium dense, medium to coarse grained, sandy GRAVEL with rock

fragments. The residual layer generally extended to rock level at an approximate

depth of 1.95m below EGL.

iv. Unit 4: Weathered Quartzitic Sandstone Rock - The weathered rock can be

described as pale pink to cream with yellowish orange stains along joints, completely

weathered, medium to coarse grained, highly fractured, very soft rock from a depth

of approximately 3.0m below EGL. Between a depth of 3.0m and 8.2m below EGL,

it becomes a highly weathered, highly fractured, soft to medium hard rock with

coarse quartzitic inclusions, and a medium hard rock from 8.2m to the final depth

drilled of 10.0m below EGL.

Plate 6 below provides a visual of the borehole core extracted from the site

Plate 6: Borehole core extracted from the borehole

12


8. GROUNDWATER

A standpipe piezometer was installed in the borehole to measure the depth of the

groundwater. The approximate depth to the groundwater level was measured on

14 June 2019 and is given in Table 2.

Table 2: Approximate Depth to Groundwater Levels

BH No. Approximate Depth to Groundwater Levels BH1 5.40m

Seasonal fluctuations in shallow groundwater levels related to rainfall patterns are,

therefore, likely intermittently during the traditionally “wet” season and/or after periods of

sustained rainfall.

The necessity for implementation of subsurface drainage measures or suitable foundation

controls should be assessed during the construction phase of the project in consultation

with the geotechnical professional.

9. DISCUSSION

9.1 Proposed Development

Information received by Geosure indicates that tower structure is proposed for the site.

Information supplied by the Engineers indicate that the tower will be approximately 18m

in height and have an approximate foundation load of 150 kN/m2 respectively. No further

structural details of the proposed building structure was 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.

9.2 Mining Activity Beneath The Site

The geological map (refer to Section 7, Plate 5) indicates at least three gold mines within

close proximity of the site.

Referring to a drawing from the Department of Mine Surveys in Pretoria, confirmed that

the site is undermined from depths between approximately 46m to 244m below EGL.

Plate 7 below is an extract of the Department of Mines building restrictions from 1970.

Plate 8 overleaf (red boundary) is an extract of the underground mine plan for the site.

13


Plate 7: Department of Mines Building Restrictions

Plate 8: Extract of Underground Mine Layout

Referring to the above building restrictions (Plate 7 refers), no building should be

constructed in an area in which mining activities occur or occurred within a depth of

91m below EGL.

14


Taking the above restrictions into account and considering the numerous building activities

located within 100m of the site, it is advised that permission be obtained from the

Department of Mineral Resources for the proposed development on the site.

9.3 Global Stability

On the basis of our observations, the site is considered stable from a geotechnical

perspective in its current condition investigated and suitable for the development a

proposed provided the recommendations set down below in this report are adopted and

certified by Geosure. Measures amount to no more than sound development practices

appropriate to the site conditions anticipated and nature of the architectural scheme known

to Geosure at the time of preparation of this report.

9.4 Trenchability Assessment

“Soft” excavation in terms of SANS 1200 is generally anticipated within the soil cover (fill

and residual sandstone) and very soft sandstone rock.

The soft to medium hard quartzitic sandstone rock are likely to classify as “Intermediate”

to “Hard” material excavation in terms of SANS 1200.

The hard sandstone rock is likely to classify as “Hard” material excavation in terms of

SANS 1200.

Nonetheless, limited “Intermediate” and “Boulder” excavations to the depths investigated

cannot be discounted and it is recommended that a contingency amount be allowed for

“Intermediate” and “Boulder” excavations at shallower depths due to likely geological

variations.

Slow excavation rates beneath the water table are considered likely. Dewatering of

excavations is considered likely.

9.5 Earthworks

It is recommended that all earthworks be carried out in accordance with SANS 1200

(current version). All vegetation, topsoil and unsuitable subgrade material should be

cleared from areas over which fills are to be built. Under fills of more than three metres in

height, further subgrade improvement may be necessary.

9.5.1 General Fills

Fill slopes should be formed to not exceed a batter of 1 vertical to 2 horizontal (≤ 26°) and

a height of 1.5m where retaining systems are not provided. Slopes exceeding 1.5m in

height will need to be designed and inspected by a competent geotechnical practitioner to

ensure long term stability.

General fills should be placed in layers not exceeding 0.25m when placed in loose

condition, and compacted to a minimum of 93% of Modified AASHTO maximum dry

density within 1 – 2 percent (wet / dry) of Optimum Moisture Content (OMC). Boulder’s

larger than 0.2m in size should not be included in the fill material. Large boulders or

15


builder’s rubble within the fill could affect compaction and mask voids into which fines

could later migrate, resulting in subsidence. Boulders / rubble may also adversely affect

foundation excavations.

Density control testing of fill material should be undertaken at appropriate intervals during

fill construction.

The sandy materials on site are considered highly erodible and sloughable due to

uncontrolled surface water runoff and special consideration will need to be given to

prevent erosion by uncontrolled stormwater runoff both during and after construction.

Platforms should also be shaped to direct water away from the fill embankments and

buildings. The use of earth bunds along the edge of fill embankments is recommended to

prevent water from overtopping and eroding fill embankments.

All banks should be grassed as soon as possible, preferably commencing during

construction.

9.5.2 General Cuts

Cuts in insitu soils may be formed to not exceed a batter of 1 vertical to 2 horizontal

(≤ 26°) and a height of not more than 1.5m where retaining systems are not provided.

Slopes exceeding 1.5m in height will need to be designed and inspected by a geotechnical

professional to ensure long term stability.

Cuts in weathered rock may be formed to batters of 1 vertical to 0.75 horizontal and to a

height not greater than 3.0m where retaining walls are not provided. Where daylighting

bedding planes are encountered during construction, it is recommended that a geotechnical

specialist be appointed to inspect the cutting and assess the global stability of the slope.

Cut and fill heights greater than 2.0m would need to be inspected and approved by a

geotechnical professional.

Sidewall collapse of excavations not battered back or shored is considered likely. The

construction and selection of appropriate retaining structures to engineer’s detail will be

critical as temporary vertical / oversteep slopes are likely to be unstable.

Where excavations intersect or approach the water table, the sidewalls will tend to become

unstable and need to be drained and laterally supported or battered back at slopes of the

order of 1 vertical in 5 horizontal. Suitable permanent dewatering by a specialist are

recommended to achieve a dry stable and safe working environment for the construction of

the proposed basement.

Workers should not enter any excavations deeper than 1.5m that are not shored or battered

back. Steeper batters can be considered but will be subject to inspection and approval by a

geotechnical professional on site during construction. It remains, however, the

responsibility of the contractor/engineer on site to ensure excavations are safe and shored

in line with requirements as set down in the current “Occupational Health and Safety” Act

85 (1993 as amended).

16


9.6 Founding Conditions

The fill layer is considered to be unsuitable as a founding layer for the tower structure and

the use of shallow concrete foundations. Based on the borehole investigation founding

depths greater 3m below EGL is considered to be suitable founding media.

9.7 Foundation Recommendations for the Proposed Fire Station

Information supplied to Geosure indicates that an approximate foundation load of

150kN/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. Pad/spread footings placed on soft to medium hard rock; and

ii. Piled foundations.

9.7.1 Pad/Strip Footings on Rock

It is recommended that all foundations for the proposed structure be taken down through

the fill and residual material and placed on the weathered sandstone rock where a

maximum net allowable bearing pressure of 200kN/m2 is considered applicable. Soft

sandstone rock was encountered from a depth of approximately 2.0m below EGL.

Total settlement is likely to be in the range less than 5mm with approximate differential

settlement taken as 50% of the total settlement.

Any loose or remoulded material must be removed from foundation trenches prior to the

casting of concrete. All footings and brickwork will need to be reinforced as determined

by a structural engineer. All foundation excavations must be inspected and approved by

Geosure to confirm bearing pressures.

9.7.2 Piled Foundation

Should there be a concern with the structural engineer with regards to upliftment of the

structure due to external forces on the proposed structure, it is considered that the foundation

loads be supported on a piled foundation socketed adequately into rock.

Consideration should be given to the use of the following piled foundation systems:

i) Continuous Flight Auger (CFA) piles; and/or

ii) Driven Cast Insitu (DCI) piles.

Other pile types may be considered if there is adequate assurance that the installation

equipment and procedures can:

i) ensure that the piles will be advanced to the required founding depth;

ii) prove the structural integrity of the pile shafts; and

iii) ensure the absence of disturbed material below the pile base.

17


Typical working loads for various pile diameters are given in Table 3 as a guideline for

budgetary purposes only.

Table 3: Central Fire Station Tower Structure: Guidelines for Typical Pile Diameter

and Allowable Working Loads

Pile Type Pile diameter

(mm)

Typical Working Load

(kN)

CFA

250 250

300 350

350 450

DCI 355 500

410 750

Pile lengths will be dependent on the final platform level and the detailed pile design must

be provided by the piling contractor. For budgeting purposes, pile lengths are anticipated to

be between 5m to 6m in length considering that the piles will be socketed into soft to

medium hard rock by at least 2m to 3m.

The determination of the required diameter, depth and reinforcing of the piles will also be

influenced by factors such as configuration and spacing of the piles in groups beneath the

pile caps, depth of the bottom of the pile cap below ground level and factors of safety or

partial factors in accordance with the design code adopted by the structural engineer.

The levels of the pile caps should be designed as shallow as possible to limit requirements

associated with temporary dewatering of any wet excavations.

Final pile founding levels will need to be reviewed by the pile designer by observing the

piles formed in the field.

It is recommended that static load capacity tests be carried out on selected piles in order to

confirm the pile working loads and pile design. The static load capacity tests should be

carried out prior to the commencement of the piling contract. Geosure’s appointment

should be extended to review the results of such static load capacity tests.

Axial settlement of single isolated piles, excluding settlement that occurs during

construction of the superstructure, should not exceed elastic shortening of the pile shaft

plus 10mm. Additional settlement due to grouping of piles would depend on spacing,

depth and number of piles in each group.

It is also recommended that low energy Frequency Response dynamic pile integrity tests

be carried out on all piles before they are covered by a pile cap. It should be specified in

the tender document that these quality assurance tests be conducted by an independent

specialist consultant to detect potential structural defects such as voids, honeycombing or

cracks that would normally be detected by quality assurance procedures for reinforced

concrete that was accessible after casting.

18


9.8 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 / or 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.

10. SUMMARY AND OBSERVATIONS

The following observation can be made about the site investigation:

i. The site is underlain by fill and residual material overlying weathered sandstone

rock.

ii. In terms of restrictions set down by the Department of Mines (1970), no building

should be constructed in an area in which mining activities occur or occurred within

a depth of 91m below EGL.

iii. It is advised that permission be requested from the Department of Mineral Resources

for the proposed development on the site.

iv. Founding options for the tower structure is discussed in Sections 9.7.

v. 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.

11. 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

19


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 27 06, 2019, 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.

APPENDIX A

●●●●●●●●●●●●●●●●●●●●●

BOREHOLE 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

Roelf Fourie Geotechnical Services

Rotary Drilling of Boreholes for

Johannesburg Central Firestation, Gauteng

HOLE No: BH1

Sheet 1 of 1

HOLE No: BH1

Sheet 1 of 1

JOB NUMBER: J015-19JOB NUMBER: J015-19

0.50

0.00

1.00

1.95

3.00

8.20

10.00

Dark grey, dense, coarse, GRAVEL.

FILL (asphalt and boulders).

Pale brown to pale dark grey, soft, fine

grained, sandy SILT. FILL.

Reddish orange, medium dense,

medium to coarse grained, sandy

GRAVEL. Residual Sandstone with rock

fragments.

Pink to cream with yellowish orange

stains along joints, completely

weathered, medium to coarse grained,

highly fractured, very soft rock.

Quartzitic SANDSTONE (Central Rand

Group).

Pink to cream with yellowish orange

stains along joints, highly weathered,

medium to coarse grained, highly

fractured, soft to medium hard rock.

Quartzitic SANDSTONE (Central Rand

Group).

Pink to cream with opaque coarse

inclusions, highly weathered, coarse

grained, medium hard rock. Quartzitic

SANDSTONE (Central Rand Group).

Scale1:75

NOTES

1) Static Water Level: 5,4m.

2) Borehole terminated at 10,5m.

CONTRACTOR :MACHINE :

DRILLED BY :PROFILED BY :

TYPE SET BY :SETUP FILE :

RFG5

-N.Govender Pr.Sci.Nat. Reg No. 400138/17

P.KhaliliSTANDARG.SET

INCLINATION :DIAM :DATE :DATE :

DATE :TEXT :

-N10 June 201914 June 2019

28/06/19 08:36..C:\LOGS\BH1.TXT

ELEVATION :X-COORD :Y-COORD :

1745m28.04347 E26.21044 S

dotPLOT 6008 PBpD069 Geosure (Pty) Ltd

HOLE No: BH1

-

HOLE No: BH1

-

1

2

3

4

5

6

7

8

9

10

1744

1743

1742

1741

1740

1739

1738

1737

1736

1735

NXC

NWD4

-

-

96

100

100

96

100

-

-

46

57

25

70

0

-

-

9

16

14

DrillMethod

andSize

% CoreRec-overy

%RQD Frac-tureFre-

quency

DEPTHScale1:75

Report to Malani Padayachee & Associates (Pty) Ltd on the … · 2019-10-24 · Geosure Gauteng...

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Transcript of Report to Malani Padayachee & Associates (Pty) Ltd on the … · 2019-10-24 · Geosure Gauteng...