View
4
Download
0
Category
Preview:
Citation preview
Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation
Report Prepared for
Report Number 544623/2
Report Prepared by
April 2019
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page i
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation
SRK Consulting (South Africa) (Pty) Ltd. Ground Floor Bay Suites 1a Humewood Rd. Humerail Port Elizabeth 6001 South Africa e-mail: portelizabeth@srk.co.za website: www.srk.co.za
Tel: +27 (0) 41 509 4800 Fax: +27 (0) 41 509 4850
SRK Project Number 544623
April 2019
Compiled by: Peer Reviewed by:
Jaco Greeff Pr Sci Nat Engineering Geologist Brent Cock Pr Sci Nat Principal Engineering Geologist
John Brown Pr Sci Nat Partner, Principal Engineering Geologist
Email: jgreeff@srk.co.za, bcock@srk.co.za
Authors:
Jaco Greeff, Brent Cock
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page ii
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Table of Contents
Disclaimer .................................................................................................................................................... iv
1 Introduction .................................................................................................................. 5
1.1 Terms of reference .............................................................................................................................. 5
2 Site description............................................................................................................. 5
2.1 Location ............................................................................................................................................... 5
2.2 Climate ................................................................................................................................................ 5
2.3 Topography, vegetation and existing infrastructure ............................................................................ 5
3 Nature of investigation ................................................................................................. 6
4 Site geology and groundwater conditions ................................................................. 8
4.1 Regional geology ................................................................................................................................ 8
4.2 Ground profile ..................................................................................................................................... 8
4.2.1 In situ soil consistency ............................................................................................................. 9
4.3 Subsurface water conditions ............................................................................................................. 10
5 Geotechnical evaluation ............................................................................................ 11
5.1 Engineering and material characteristics .......................................................................................... 11
5.2 Problematic soils ............................................................................................................................... 13
5.3 Suitability of the in-situ material for use during construction ............................................................ 13
5.4 Excavatability .................................................................................................................................... 13
5.5 Aggressiveness of the subsurface environment towards concrete, fibre cement concrete pipes and metals ................................................................................................................................................ 14
5.6 Residential site class designations ................................................................................................... 14
6 Foundation recommendations and solutions .......................................................... 15
6.1 General founding conditions ............................................................................................................. 15
6.2 Foundation design............................................................................................................................. 15
6.2.1 Strip footings ......................................................................................................................... 15
7 Drainage ...................................................................................................................... 15
8 Special precautionary measures (if any) .................................................................. 15
Appendices ...................................................................................................................... 17
Appendix A: Soil Profiles .............................................................................................. 18
Appendix B: Photographs ............................................................................................ 20
Appendix C: DPL Profiles ............................................................................................. 24
Appendix D: Laboratory Certificates ........................................................................... 26
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page iii
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
List of figures Figure 2-1: Site location (North up) .................................................................................................................... 6
Figure 2-2: Typical site conditions (Looking south). ........................................................................................... 6
Figure 3-1: Test pit layout (North up) .................................................................................................................. 7
Figure 4-1: Regional geology map (North up) .................................................................................................... 8
Figure 4-2: Typical soil profile ............................................................................................................................. 9
Figure 4-3: Combined DPL graphs ................................................................................................................... 10
Figure 4-4: Ferricrete at the surface ................................................................................................................. 11
Figure 5-1: Combined grading profiles ............................................................................................................. 12
List of Tables Table 3-1: Sample submission summary ........................................................................................................... 7
Table 5-1: Summarised laboratory results........................................................................................................ 12
Table 5-2: Test pit excavatability summary ...................................................................................................... 13
Table 5-3: SANS 1200 D earthworks classification .......................................................................................... 13
Table 5-4: Residential Site Class designation. ................................................................................................. 14
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page iv
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Disclaimer The opinions expressed in this Report have been based on the information supplied to SRK Consulting
(South Africa) (Pty) Ltd (SRK) by CES (hereafter referred to as ‘’the Client’’). The opinions in this
Report are provided in response to a specific request from the Client to do so. SRK has exercised all
due care in reviewing the supplied information. Whilst SRK has compared key supplied data with
expected values, the accuracy of the results and conclusions from the review are entirely reliant on
the accuracy and completeness of the supplied data. SRK does not accept responsibility for any errors
or omissions in the supplied information and does not accept any consequential liability arising from
commercial decisions or actions resulting from them. Opinions presented in this report apply to the
site conditions and features, as they existed at the time of SRK’s investigations, and those reasonably
foreseeable. These opinions do not necessarily apply to conditions and features that may arise after
the date of this Report, about which SRK had no prior knowledge nor had the opportunity to evaluate
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 5
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
1 Introduction SRK Consulting (South Africa) (Pty) Ltd (SRK) were appointed by CES (the Client) to conduct a
geotechnical investigation to facilitate the extension of the residential area on the corner of Kort Street
and Buiten Street (Portion 5 of Farm Hazia JP No 240) on the southern outskirts of Zeerust in the
North West Province.
The project aims to establish a middle-income residential area. The site (5.01 hectares) is expected
to be sub-divided into approximately 80 stands and sold to prospective residents. Adjacent municipal
services, including water, electricity, waste removal and roads will be extended into the area.
The report is required for foundation design and NHBRC requirements.
1.1 Terms of reference
Conduct a Phase 1 Geotechnical Site Investigation according to the National Department of Housing’s
Generic Specification (GFSH) published in 2002. The general outline of the report is provided below:
• Site description (regional and local).
• Nature of investigation
• Site geology and groundwater conditions.
• Geotechnical evaluation
• NHBRC Site Classification.
• Foundation recommendations and solutions.
• Drainage.
• Special precautionary measures (if any).
2 Site description
2.1 Location
The site is located on the southern outskirt of Zeerust in the North-West province. The location of the
site is shown in Figure 2.1.
2.2 Climate
Zeerust normally receives about 439 mm of rain per year, with rainfall occurring mainly during
summer1. Lowest rainfall is expected in June, peaking in January.
2.3 Topography, vegetation and existing infrastructure
The site is flat lying with an average estimated fall of ground in the order of 1:100 towards the east.
The site is surrounded by existing low-cost houses, with access roads along the western, northern and
eastern boundary. A temporary construction site camp was noted towards the central- to western part
of the site. It is unknown at this time whether they are involved in this project.
Vegetation is characterised by open grass fields, with trace small bushes. Typical site conditions are
shown in Figure 2.2.
1 http://www.saexplorer.co.za/south-africa/climate/zeerust_climate.asp
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 6
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Figure 2-1: Site location (North up)
Figure 2-2: Typical site conditions (Looking south).
3 Nature of investigation Eight test pits were excavated at selected positions within the proposed area of development, using a
track-loaded backhoe (TLB) excavator to a depth ranging from 1.6 m to 3.0 m below the surface. The
positions of the test pits are shown in Figure 3-1.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 7
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Dynamic Probe Light (DPL) penetrometer tests 2were conducted from surface at each test pit to a
depth ranging from 0.5 m to 0.9 m below surface.
Disturbed soil samples were collected and submitted to a SANAS-accredited soil testing laboratory for
the following tests:
• Grading analyses to determine particle size distribution, including clay content (hydrometer) and
Atterberg Limits,
• Moisture content: MOD and saturated CBR (California Bearing Ratio).
• Aggressivity Test (Basson Method)
A sample submission summary is included in (Table 3-1).
Table 3-1: Sample submission summary
Test Depth sample taken (m)
TP1 TP2 TP4 TP6 TP7 TP8
Foundation Indicator 2.7 - - 1.9 - 2.5
Road Indicator & Moisture: density
relationship and CBR. - 0.9 – 1.1 0.8 – 1.0 - 1.0 – 1.2 -
Aggressivity Test (Basson Method) - 0.9 0.8 - - -
Figure 3-1: Test pit layout (North up)
2 Done to determine the penetration resistance of soils.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 8
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
4 Site geology and groundwater conditions
4.1 Regional geology
The published geological map for the area, reproduced as Figure 4-1, indicates that the site is
underlain by the Timeball Hill Formation (Greyish brown “Vt”) and the Rooihoogte Formation (Orange
brown with black dots “Vrs”) (Pretoria Group; Transvaal Supergroup). Both are characterised by
conglomerates, siltstone/mudstone and fine-grained sandstone. Diabase (pale green “di”) intrusions
and Alluvium deposits (pale yellow “Q”) are mapped within the vicinity of the site.
Figure 4-1: Regional geology map (North up)
4.2 Ground profile
The site is generally underlain by alluvium described as slightly moist to moist, reddish brown,
generally medium dense to dense though occasionally loose, fissured clayey sand with minor to
abundant ferruginous nodules and trace ferricrete accretions. The horizon was intersected from
surface to an average depth of 0.6 m below the surface.
The alluvium is underlain by the Timeball Hill Formation. The horizon is characterised by alternating
zones of greyish blue banded light grey, moderately weathered, soft rock slate, and reddish brown
stained yellow, highly to completely weathered, very-soft rock slate to very stiff silty fine sand,
intersected to a depth ranging from 1.6 m to more than 3.0 m below the surface.
A typical soil profile is shown in Figure 4-2.
The detailed soil profiles are included in Appendix A.
Selected photographs are included in Appendix B.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 9
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Figure 4-2: Typical soil profile
4.2.1 In situ soil consistency
DPL tests were conducted adjacent to each of the test pits from surface to refusal or near refusal
(penetration rate decreases to less than 3 mm per blow).
The soil consistency improves rapidly with depth through the ferruginised alluvium before refusing on,
or within the weathered slate horizons.
Combined DPL graphs are shown in Figure 4-3
Individual DPL profiles are shown in Appendix C.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 10
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Figure 4-3: Combined DPL graphs
4.3 Subsurface water conditions
No subsurface seepage was intersected during the excavation or backfilling of the test pits.
The presence of ferruginous nodules within the colluvium and visible ferricrete at the surface (Figure
4-4) is inferred to represent the upper limit of a historical, fluctuating water table.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 11
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Figure 4-4: Ferricrete at the surface
5 Geotechnical evaluation
5.1 Engineering and material characteristics
The particle size distribution (Figure 5-1) indicates that the highly to completely weathered slate
(excluding the moderately weathered, greyish blue banded light grey slate) have roughly similar
grading profiles with a moderate silt content, but very low clay content. The Unified Soil Classification
(USCS) is predominantly SC with occasional SC-SM. A plot of the clay content and overall PI on a van
der Merwe chart indicates that the potential for heave is Low.
The detailed laboratory results are summarised in Table 5-1.
The detailed certificates are included in Appendix D.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 12
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Table 5-1: Summarised laboratory results
TP
ID
Fro
m (m
)
To
(m)
Orig
in
Particle Size Distribution
Gra
din
g M
od
ulu
s
Liq
uid
Lim
it (wh
ole
)
PI (w
ho
le)
Lin
ear S
hrin
kag
e (w
ho
le)
US
CS
(AS
TM
D 2
487)
Heav
e
Basso
n In
dex
MD
D (k
g/m
3)
OM
C (%
)
CB
R 1
00%
CB
R 9
8%
CB
R 9
5%
CB
R 9
3%
CB
R 9
0%
MA
AS
HT
O S
well %
TR
H14
> 4
.75 m
m
4.7
5 - 2
.36
mm
2.3
6 - 0
.42
5 m
m
0.4
25 - 0
.075 m
m
0.0
75 - 0
.002 m
m
< 0
.002
mm
TP2 0.9 1.1 Timeball Hill Formation 34 17 16 6 27 - 1.91 13 5 2.8 SC Low Corrosive - Aggressive 1847 15 44 32 20 14 9 0.5 G9
TP4 0.8 1 Timeball Hill Formation 39 16 8 22 15 - 2.03 6 2 0.9 SC-SM Low Corrosive - Aggressive 2087 9.2 39 27 16 11 6 0.5 G10
TP7 1 1.2 Timeball Hill Formation 26 21 11 9 33 - 1.72 14 7 3.4 SC Low - 1856 17 16 16 15 15 15 0.9 G7
TP1 2.7 Timeball Hill Formation 36 13 10 7 29 5 1.74 19 8 4.3 SC Low - - - - - - - - - -
TP6 1.9 Timeball Hill Formation 42 12 11 6 26 3 1.90 14 6 3.2 SC Low - - - - - - - - - -
TP8 2.5 Timeball Hill Formation 41 16 9 6 23 5 1.95 12 5 2.9 SC Low - - - - - - - - - -
Figure 5-1: Combined grading profiles
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 13
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
5.2 Problematic soils
The following problematic soils have been identified within South Africa: expansive clays, soft clays,
dispersive soils, pedogenic horizons and collapsible soils.
The ferruginous colluvium has a fissured soil structure, indicating historic soil movement (expansion
during wetting and shrinkage during drying). No soil samples were collected from this horizon;
however, the ferruginous clayey sand was only intersected to a maximum depth of 0.7 m and is not
considered to be problematic.
5.3 Suitability of the in-situ material for use during construction
The highly to completely weathered slate material is classified between a G7 and a G8 according to
COLTO 1998 standards and is considered suitable for selected and subgrade material within
road/pavement layer works and engineered fill.
5.4 Excavatability
The excavatability of the site is assessed according to the SANS 1200 D earth works specifications
(Table 5-3).
The excavatability of the site is classified as soft to a depth ranging from 1.6 m to more than 3.0 m
below the surface. The excavatability on site is for the most part dependent on the depth at which the
greyish blue slate is intersected. Note that the TLB was able to excavate through the upper greyish
blue slate intersected at a depth ranging from 0.4 m to 0.7 m below surface (TP1, TP5 to TP6 and
TP8). The TLB was not able to excavate through the lower greyish blue slate layer intersected at a
depth ranging from generally 1.4 m to occasionally 2.6 m below surface (TP2 to TP7). The SANS
1200 D excavatability per test pit is summarised in Table 5-2.
Table 5-2: Test pit excavatability summary
SANS 1200 D TLB excavation depth (m)
TP1 TP2 TP3 TP4 TP5 TP6 TP7 TP8
Soft 3.0 1.6 1.6 1.7 1.8 2.8 1.8 2.8
Intermediate grading into Hard rock 3.0 3.0 3.0 3.0 3.0 3.0 3.0
Therefore, the excavatability is unlikely to prove problematic for shallow excavations e.g. average 1.7
m depth but could prove problematic for excavations deeper than this on occasion.
Table 5-3: SANS 1200 D earthworks classification
Classification Description
Restricted excavations
Soft Material which can be efficiently removed by a back-acting excavator of fly wheel power >0.10 kW for each mm of tined bucket width
Intermediate
Material which can be removed by a back-acting excavator of fly wheel power >0.10 kW for each mm of tined bucket width or with the use of pneumatic tools before removal by a machine capable of removing soft material
Hard rock Material that cannot be removed without blasting or wedging and splitting
Non-restricted excavations
Soft Material which can be efficiently removed or loaded, without prior ripping, by any of the following plant:
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 14
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Classification Description
a bulldozer or a track-type front end loader having an approximate mass of 22 tonne and fly wheel power of 145 kW
a tractor-scraper unit having an approximate mass of 28 tonne and fly wheel power of 245 kW pushed during loading by a bulldozer equivalent to that described above
Intermediate Material which can be efficiently ripped by a bulldozer having an approximate mass of 35 tonne and a fly wheel power of 220 kW
Hard rock Material that cannot be efficiently ripped by a bulldozer having an approximate mass of 35 tonne and a fly wheel power of 220 kW
Boulder Class A Material containing more than 40% by volume of boulders of size between 0.03 m3 and 20 m3 in a matrix of soft material or smaller boulders
Boulder Class B Material containing 40% or less by volume of boulders of size between 0.03 m3 and 20 m3 in a matrix of soft material or smaller boulders
5.5 Aggressiveness of the subsurface environment towards concrete, fibre cement concrete pipes and metals
Two representative soil samples were collected (TP2 @ ~1.0 m and TP4 @ ~0.9 m) from the Timeball
Hill Formation and submitted for Basson Index tests.
The highly to completely weathered very-soft rock slate is aggressive towards buried concrete, fibre
cement concrete pipes and corrosive towards steel.
5.6 Residential site class designations
The alluvium and completely weathered slate is classified as S for compressible soils characterised
by fine grained soils (clayey silts and clayey sands of low plasticity), sands, sandy and gravelly soils
with an expected range of total soil movement less than 10 mm.
If exposed within foundation trenches, the greyish blue, soft rock slate is classified as R i.e. stable
founding material.
Table 5-4: Residential Site Class designation.
TYPICAL FOUNDING MATERIAL CHARACTER OF
FOUNDING MATERIAL
EXPECTED RANGE OF TOTAL SOIL MOVEMENT
(mm)
ASSUMED DIFFERENTIAL SETTLEMENT (% OF TOTAL)
SITE CLASS
Rock (excluding mud rocks which may exhibit swelling to
some depth) STABLE NEGLIGIBLE - R
Fine grained soils with moderate to very high plasticity
(clays, silty clays, clayey silts and sandy clays)
EXPANSIVE SOILS
<7.5 50% H
7.5 - 15 50% H1
15 - 30 50% H2
>30 50% H3
Silty sands, sands, sandy and gravelly soils
COMPRESSIBLE AND
POTENTIALLY COLLAPSIBLE
SOILS
<5 75% C
5 - 10 75% C1
>10 75% C2
Fine grained soils (clayey silts and clayey sands of low
plasticity), sands, sandy and gravelly soils
COMPRESSIBLE SOILS
<10 50% S
10 - 20 50% S1
>20 50% S2
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 15
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
TYPICAL FOUNDING MATERIAL CHARACTER OF
FOUNDING MATERIAL
EXPECTED RANGE OF TOTAL SOIL MOVEMENT
(mm)
ASSUMED DIFFERENTIAL SETTLEMENT (% OF TOTAL)
SITE CLASS
Contaminated soils, controlled fill, dolomitic areas, landslip, landfill, marshy areas, mine
waste fill, mining subsidence, reclaimed areas, uncontrolled
fill, very soft silts/silty clays
VARIABLE P
6 Foundation recommendations and solutions The proposed development is indicated to consist of single-storey, middle-class residential houses of
masonry design. The foundation design assessment is therefore considered to be generalized until
additional details are made available.
6.1 General founding conditions
The site is generally underlain by a 0.6 m thick layer of ferruginous alluvium, below which intersecting
alternating layers of either greyish blue soft-rock slate or reddish brown very soft rock slate with very
stiff silty fine sand occurs to depths ranging from 1.6 m to more than 3.0 m.
No sub-surface seepage was intersected during excavations. The ferricrete accretions at the surface
indicate the upper limit of an historic, fluctuating water table.
The fissured soil structure of the ferruginous colluvium indicates historic drying and wetting of the near-
surface soils, but this is not considered to be problematic for the foundations (as they will be carried
below this material), but cognisance of this needs to be taken beneath floor slabs (compact a layer of
granular soil beneath the floor slabs), and in areas of hardstand and road/pavement design.
6.2 Foundation design
6.2.1 Strip footings
Conventional strip foundations will be suitable for the houses. Cast reinforced strip footings below the
upper colluvial materials at a depth of about 0.7 m below the surface, that is, within/on top of the grey
blue or reddish-brown slate. As a general recommendation foundation can be designed using an
allowable ground bearing capacity in the order of 150 kPa when founding within the residual soils or
weathered slate.
7 Drainage The flat-lying topography might lead to ponding of storm water after heavy rainfall or periods of
sustained rainfall. The saturated CBR results for samples collected from the completely weathered
slate show some softening of the material, though this is not considered to be severe. Management
of storm water is considered important. Include measures during and post construction to prevent
storm water ingress into the foundation trenches prior to casting. Ponding of water against structures
should be avoided.
8 Special precautionary measures (if any) It is recommended that protective measures are put in place to protect buried concrete, fibre cement
concrete pipes and steel from the corrosive nature of the founding material.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 16
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Prepared by
Jaco Greeff Pr Sci Nat
Engineering Geologist
Brent Cock Pr Sci Nat
Principal Engineering Geologist
Reviewed and Approved by
John Brown Pr Sci Nat
Principal Engineering Geologist, Partner
All data used as source material plus the text, tables, figures, and attachments of this document have
been reviewed and prepared in accordance with generally accepted professional engineering and
environmental practices.
SRK Consulting: Project No: 544623 Zeerust - Kort Site Page 17
GREJ/COCB/brow 544623_2 Zeerust Phase 1 Housing Development (Kort Site) Geotechnical Investigation_FINAL April 2019
Appendices
Appendix A: Soil Profiles
Test Pit ID TP1 TP2 TP3 TP4 TP5 TP6 TP7 TP8
Plant Hire Company J-CAT Plant Hire J-CAT Plant Hire J-CAT Plant Hire J-CAT Plant Hire J-CAT Plant Hire J-CAT Plant Hire J-CAT Plant Hire J-CAT Plant Hire
Plant Type TLB TLB TLB TLB TLB TLB TLB TLB
Profiled By Jaco Greeff Jaco Greeff Jaco Greeff Jaco Greeff Jaco Greeff Jaco Greeff Jaco Greeff Jaco Greeff
Date Profiled 19 February 2019 19 February 2019 19 February 2019 19 February 2019 19 February 2019 19 February 2019 19 February 2019 19 February 2019
Latitude -25.571052° -25.571299° -25.571550° -25.571797° -25.572207° -25.571844° -25.571633° -25.571438°
Longitude 26.092463° 26.091310° 26.090034° 26.088214° 26.088912° 26.090701° 26.091805° 26.092909°
Description Origin
Moist, brown, loose, intact fine sand with minor root material. Alluvium 0.3
Slightly moist, light brown, medium dense, intact fine sand with minor ferruginous granules
and trace ferricrete accretions.0.4
Moist, reddish brown, medium dense to dense, fissured clayey sand with minor to abundant
ferruginous nodules and trace ferricrete accretions.0.6 0.6 0.6 0.4 0.4 0.6 0.7
Reddish brown stained and banded yellow and grey, very thinly bedded, moderately
jointed, highly to completely weathered very soft-rock with patches moderately
ferruginised slate and very dense silty fine sand.
1.4 0.6
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderately
jointed, soft-rock slate.1.3 0.9 0.9 1.5
Reddish brown banded yellow and grey, very thinly bedded, moderately jointed, highly to
completely weathered very soft-rock slate to very dense silty fine sand.1.4 1.3 1.4 1.6
Reddish brown banded greyish blue, highly to completely weathered, very thinly bedding,
occasionally relict jointed, very soft-rock slate to very dense silty fine sand.
3.0 2.6
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderately
jointed, soft-rock slate.1.6 1.6 1.7 1.6 2.8 1.8
Yellowish orange, highly weathered, very thinly bedded, moderately jointed, soft-rock
slate to very dense silty fine sand.1.8 2.8
Refusal No Refusal on slate Refusal on slate Refusal on slate Refusal in slate Refusal on slate Refusal on slate No
Subsurface seepage None None None None None None None None
544623 GEOTECHNICAL INVESTIGATION (KORT SITE)
Excavation depth (m)
Timeball Hill Formation
Ferruginous Alluvium
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 1Sheet 1 of 1
HOLE No: TP 1Sheet 1 of 1
HOLE No: TP 1Sheet 1 of 1
HOLE No: TP 1Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.60
0.00
1.30
3.00
Moist, reddish brown, medium dense to dense, fissured, clayey, SAND with minor toabundant ferrigunised nodules and trace ferricrete accretions. Ferrigunised Alluvium.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Reddish brown banded greyish blue, highly to completely weathered, very thinlybedding, occasionally relict jointed, very soft rock slate to very dense, silty, fine SAND.Timeball Hill Formation.
Scale1:15
NOTES
1) Not to refusal.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26092463-25571052
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 1HOLE No: TP 1HOLE No: TP 1HOLE No: TP 1
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 2Sheet 1 of 1
HOLE No: TP 2Sheet 1 of 1
HOLE No: TP 2Sheet 1 of 1
HOLE No: TP 2Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.40
0.00
1.40
1.60
Slightly moist, light brown, medium dense, intact, fine SAND with minor ferrigunisedgranules and trace ferricrete accretions. Ferrigunised Alluvium.
Reddish brown banded yellow and grey, very thinly bedded, moderately jointed, highlyto completely weathered, very soft rock slate to very dense, silty, fine SAND. TimeballHill Formation.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Scale1:10
NOTES
1) Refusal on slate.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26091310-25571299
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 2HOLE No: TP 2HOLE No: TP 2HOLE No: TP 2
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 3Sheet 1 of 1
HOLE No: TP 3Sheet 1 of 1
HOLE No: TP 3Sheet 1 of 1
HOLE No: TP 3Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.60
0.00
1.30
1.60
Moist, reddish brown, medium dense to dense, fissured, clayey, SAND with minor toabundant ferrigunised nodules and trace ferricrete accretions. Ferrigunised Alluvium.
Reddish brown banded yellow and grey, very thinly bedded, moderately jointed, highlyto completely weathered, very soft rock slate to very dense, silty, fine SAND. TimeballHill Formation.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Scale1:10
NOTES
1) Refusal on slate.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26090034-25571550
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 3HOLE No: TP 3HOLE No: TP 3HOLE No: TP 3
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 4Sheet 1 of 1
HOLE No: TP 4Sheet 1 of 1
HOLE No: TP 4Sheet 1 of 1
HOLE No: TP 4Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.30
0.00
0.60
1.40
1.70
Moist, brown, loose, intact, fine SAND with minor root material. Alluvium.
Moist, reddish brown, medium dense to dense, fissured, clayey SAND with minor toabundant ferrigunised nodules and trace ferricrete accretions. Ferrigunised Alluvium.
Reddish brown stained and banded yellow and grey, very thinly bedded, moderatelyjointed, highly to completely weathered, very soft rock with patches moderatelyferruginised slate and very dense, silty, fine SAND. Timeball Hill Formation.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Scale1:10
NOTES
1) Refusal on slate.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26088214-25571797
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 4HOLE No: TP 4HOLE No: TP 4HOLE No: TP 4
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 5Sheet 1 of 1
HOLE No: TP 5Sheet 1 of 1
HOLE No: TP 5Sheet 1 of 1
HOLE No: TP 5Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.40
0.00
0.90
1.40
1.60
1.80
Moist, reddish brown, medium dense to dense, fissured, clayey SAND with minor toabundant ferrigunised nodules and trace ferricrete accretions. Ferrigunised Alluvium.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Reddish brown stained and banded yellow and grey, very thinly bedded, moderatelyjointed, highly to completely weathered, very soft rock with patches moderatelyferruginised slate and very dense, silty, fine SAND. Timeball Hill Formation.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Yellowish orange, highly weathered, very thinly bedded, moderately jointed, soft rockslate to very dense, silty, fine SAND. Timeball Hill Formation.
Scale1:10
NOTES
1) Refusal in slate.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26088912-25572207
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 5HOLE No: TP 5HOLE No: TP 5HOLE No: TP 5
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 6Sheet 1 of 1
HOLE No: TP 6Sheet 1 of 1
HOLE No: TP 6Sheet 1 of 1
HOLE No: TP 6Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.40
0.00
0.60
0.90
2.60
2.80
Moist, reddish brown, medium dense to dense, fissured, clayey SAND with minor toabundant ferrigunised nodules and trace ferricrete accretions. Ferrigunised Alluvium.
Reddish brown banded yellow and grey, very thinly bedded, moderately jointed, highlyto completely weathered, very soft rock slate to very dense, silty, fine SAND. TimeballHill Formation.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Reddish brown banded greyish blue, highly to completely weathered, very thinlybedding, occasionally relict jointed, very soft rock slate to very dense, silty, fine SAND.Timeball Hill Formation.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Scale1:15
NOTES
1) Refusal on slate.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26090701-25571844
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 6HOLE No: TP 6HOLE No: TP 6HOLE No: TP 6
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 7Sheet 1 of 1
HOLE No: TP 7Sheet 1 of 1
HOLE No: TP 7Sheet 1 of 1
HOLE No: TP 7Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.60
0.00
1.60
1.80
Moist, reddish brown, medium dense to dense, fissured, clayey, SAND with minor toabundant ferrigunised nodules and trace ferricrete accretions. Ferrigunised Alluvium.
Reddish brown banded yellow and grey, very thinly bedded, moderately jointed, highlyto completely weathered, very soft rock slate to very dense, silty, fine SAND. TimeballHill Formation.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Scale1:10
NOTES
1) Not to refusal.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26091805-25571633
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 7HOLE No: TP 7HOLE No: TP 7HOLE No: TP 7
KORT SITE GEOTECHNICAL INVESTIGATION
HOLE No: TP 8Sheet 1 of 1
HOLE No: TP 8Sheet 1 of 1
HOLE No: TP 8Sheet 1 of 1
HOLE No: TP 8Sheet 1 of 1
JOB NUMBER: 544623JOB NUMBER: 544623
0.70
0.00
1.50
2.80
Moist, reddish brown, medium dense to dense, fissured, clayey, SAND with minor toabundant ferrigunised nodules and trace ferricrete accretions. Ferrigunised Alluvium.
Greyish blue banded light grey, very thinly bedded, moderately weathered, moderatelyjointed, soft rock slate. Timeball Hill Formation.
Yellowish orange, highly weathered, very thinly bedded, moderately jointed, soft rockslate to very dense, silty, fine SAND. Timeball Hill Formation.
Scale1:15
NOTES
1) Not to refusal.
2) No water seepage.
CONTRACTOR :
MACHINE :
DRILLED BY :
PROFILED BY :
TYPE SET BY :
SETUP FILE :
J-CAT PLANT HIRETLB
JACO GREEFF
ADON
STANDARD.SET
INCLINATION :
DIAM :
DATE :
DATE :
DATE :
TEXT :
VERTICAL
19 FEBRUARY 201919 FEBRUARY 2019
27/03/2019 15:56
..rgsig\544623Kortsite.txt
ELEVATION :
X-COORD :
Y-COORD :
26092909-25571438
dotPLOT 7018 PBpHD009 SRK Consulting
HOLE No: TP 8HOLE No: TP 8HOLE No: TP 8HOLE No: TP 8
Appendix B: Photographs
TP 01 (01) TP 01 (02)
TP 02 (01) TP 02 (02)
TP 03 (01) TP 03 (02)
Zeerust Housing Development (Kort Site)
Geotechnical Investigation Photographs
Project No.
544623
TP 04 (01) TP 04 (02)
TP 05 (01) TP 05 (02)
TP 06 (01) TP 06 (02)
Zeerust Housing Development (Kort Site)
Geotechnical Investigation Photographs
Project No.
544623
TP 07 (01) TP 07 (02)
TP 08 (01) TP 08 (02)
Zeerust Housing Development (Kort Site)
Geotechnical Investigation Photographs
Project No.
544623
Appendix C: DPL Profiles
18
Appendix D: Laboratory Certificates
Telephone: +2712 – 349 – 1066 Facsimile: +2712 – 349 – 2064 Email: accounts@waterlab.co.za
WATERLAB (PTY) LTD
CERTIFICATE OF ANALYSES BASSON INDEX
Date received: 2019-02-21 Date completed: 2019-03-11 Project number: 151 Report number: 81093 Order number: 68126
Client name: SRK Consulting (South Africa) Contact person: Jaco Greeff Address: PO Box 55291, Northlands, 2116 Email: jgreef@srk.co.za Telephone: 041 509 4800 Cell: 079 273 4649 Fax: 041 509 4850
S. Laubscher______________________ Assistant Geochemistry Project Manager The information contained in this report is relevant only to the sample/samples supplied to WATERLAB (Pty) Ltd. Any further use of the above information is not the responsibility or liability of WATERLAB (Pty) Ltd. Except for the full report, parts of this report may not be reproduced without written approval of WATERLAB (Pty) Ltd.
Page 1 of 3
23B De Havilland Crescent Persequor Techno Park, Meiring Naudé Road, Pretoria P.O. Box 283, 0020
Analyses in mg/ℓ (Unless specified otherwise)
Sample Identification:
Kort Site 1-2 @ 0.9 Kort Site 1-4 @ 0.8
Sample Number 55976 55977
pH Value at 25°C 4.2 5.6
pHs Value at 20°C (calc) 10.6 10.6
Electrical Conductivity in mS/m at 25°C 1.3 3.8
Total Dissolved Solids* (calc) <10 25
Total Alkalinity as CaCO3 8 8
Total Hardness as CaCO3 (calc) 7 7
Calcium Hardness as CaCO3 (calc) 2 2
Calcium as Ca <1 1
Magnesium as Mg <1 <1
Free & Saline Ammonia <0.1 <0.1
Ammonium as NH4 (calc) <0.3 <0.3
Sulphate as SO4 <2 6
Chloride as Cl <2 3
Langelier Index at 20°C (calc) -6.4 -5.0
Ryznar Index at 20°C (calc) 17.0 15.7
Corrosivity Ratio (calc) 0.3 1.3
Leaching Index [LCSI] (calc) 4971 3975
Spalling Index [SCSI] (calc) 1 1
Aggressiveness Index [Nc] (calc) 4971 3976
*TDS Calculated EC X 6.7
2:1 Distilled Water : Soil Extract
Important notes (see table for corrections on p.3): 1. The above aggressiveness index is only applicable for conditions of laminar flow at a mean annual temperature of 20°C. 2. For stagnant/turbulent conditions the aggressiveness index must be corrected. 3. For wet/dry cycling conditions (for example in tidal zones) the aggressiveness index must be corrected. 4. For mean annual temperatures lower/higher than 20°C the aggressiveness index must be corrected.
Telephone: +2712 – 349 – 1066 Facsimile: +2712 – 349 – 2064 Email: accounts@waterlab.co.za
WATERLAB (PTY) LTD
CERTIFICATE OF ANALYSES BASSON INDEX
Date received: 2019-02-21 Date completed: 2019-03-11 Project number: 151 Report number: 81093 Order number: 68126
Client name: SRK Consulting (South Africa) Contact person: Jaco Greeff Address: PO Box 55291, Northlands, 2116 Email: jgreef@srk.co.za Telephone: 041 509 4800 Cell: 079 273 4649 Fax: 041 509 4850
S. Laubscher______________________ Assistant Geochemistry Project Manager The information contained in this report is relevant only to the sample/samples supplied to WATERLAB (Pty) Ltd. Any further use of the above information is not the responsibility or liability of WATERLAB (Pty) Ltd. Except for the full report, parts of this report may not be reproduced without written approval of WATERLAB (Pty) Ltd.
Page 2 of 3
23B De Havilland Crescent Persequor Techno Park, Meiring Naudé Road, Pretoria P.O. Box 283, 0020
Guidelines for assessing overall aggressiveness (Nc):
Aggressiveness Towards Concrete and Fibre Cement Pipes
Index Aggressive Neutral Non- Aggressive
a) Stability pH (pHs) >Ph = pH <pH
b) Langelier Index Neg. Value Zero Pos. Value
c) Ryznar Index >7.5 6-7 <6
Corrosiveness Towards metals
Corrosivity >0.2
Sample Name Sample Number Corrosivity Indices Basson Index
Kort Site 1-2 @ 0.9 55976 Corrosive Aggressive
Kort Site 1-4 @ 0.8 55977 Corrosive Aggressive
Nc Aggressiveness
Not greater than 300 None to mild
400-700 Mild to moderate
800-1000 High
= or > 1 100 Very high
Telephone: +2712 – 349 – 1066 Facsimile: +2712 – 349 – 2064 Email: accounts@waterlab.co.za
WATERLAB (PTY) LTD
CERTIFICATE OF ANALYSES BASSON INDEX
Date received: 2019-02-21 Date completed: 2019-03-11 Project number: 151 Report number: 81093 Order number: 68126
Client name: SRK Consulting (South Africa) Contact person: Jaco Greeff Address: PO Box 55291, Northlands, 2116 Email: jgreef@srk.co.za Telephone: 041 509 4800 Cell: 079 273 4649 Fax: 041 509 4850
S. Laubscher______________________ Assistant Geochemistry Project Manager The information contained in this report is relevant only to the sample/samples supplied to WATERLAB (Pty) Ltd. Any further use of the above information is not the responsibility or liability of WATERLAB (Pty) Ltd. Except for the full report, parts of this report may not be reproduced without written approval of WATERLAB (Pty) Ltd.
Page 3 of 3
23B De Havilland Crescent Persequor Techno Park, Meiring Naudé Road, Pretoria P.O. Box 283, 0020
To correct for: Multiply By: (see Notes 2 to 5 below)
Turbulence LCSI 1.75
Stagnance LCSI 0.5
Temperature LCSI, SCSI, N7
Where N7=0.2 x Cl in mg/l (1+ [0.05 x (T-20)])
Wet-dry cycles SCSI
0.23 x 10-6 x TDS x DTF x CPA Where: DTF = Dry Time Fraction CPA = wet-dry cycles per annum
Note 1: Only if the concrete contains embedded steel. Note 2: To preserve the correct logical relationships when dealing with the negative sub indices (ie LCSI or SCSI having minus values) they should be multiplied by the reciprocal of the relevant factor indicated in this column Note 3: If more than one correction is required, multiply by the product of the individual correction factors Note 4: Use subscript c to indicate that the index has been corrected, eg for turbulent conditions LCSIc = LCSI x 1.75 Note 5: Round off corrected indices to the nearest 100.
SRK Report Distribution Record
Report No. 544623/2
Copy No. Electronic
Name/Title Company Copy Date Authorised by
Aidan Gouws CES Electronic 09 May 2019 Brent Cock
Project file SRK Consulting (South Africa) (Pty) Ltd Electronic 09 May 2019 Brent Cock
Approval Signature:
This report is protected by copyright vested in SRK (South Africa) (Pty) Ltd. It may not be reproduced
or transmitted in any form or by any means whatsoever to any person without the written permission
of the copyright holder, SRK.
Recommended