drennan maud (pty) ltd · geotechnical investigation for the proposed umbumbulu shopping centre 1....

DRENNAN MAUD (PTY) LTDGEOTECHNICAL ENGINEERS AND ENGINEERING GEOLOGISTSIncorporating Drennan Maud & Partners (Est.1975) and GAP Consulting

Durban Head Office Info@ drennanmaud.com

68 Peter Mokaba Ridge, Tollgate, 4001 www.drennanmaud.com

P.O. Box 30464, Mayville, 4058

T: +27 31 201 8992 F: +27 31 201 7920

Reg. No. 2014/038872/07

Margate Office

Unit 7 Gayridge Business Park No. 2

13 W ingate Avenue, Margate 4275

T: +27 39 3122 588 F: 0866 0275 53

Directors:M.J.F BENET [Pr.Sci.Nat. B.Sc. (Hons) M.Sc. FSAIEG], M.J.HADLOW [Pr.Sci.Nat. B.Sc.(Hons.) MSAIEG] Managers: M.J.F. BENET (Durban), G. NTAKA (Margate)

Our Ref : 32225

Your Ref :

10 May 2018th

INPRODEV (PTY) LTD

P.O. Box 1371

Kloof

3640

Attention: Mr. A Theunissen

Dear Sir,

GEOTECHNICAL INVESTIGATION FOR THE PROPOSED

UMBUMBULU SHOPPING CENTRE

1. INTRODUCTION AND TERMS OF REFERENCE

Drennan Maud (Pty) Ltd was appointed by Mr A. Theunissen of Inprodev (Pty) Ltd on the

27 February 2018 to carry out a geotechnical investigation for the proposed new shoppingth

centre in the town of Umbumbulu.

The site was visited on the 29 of March 2018 during which time the field investigation wasth

carried out. The aim of the investigation was to :

- Determine the prevailing subsoil conditions and geology underlying the site,

- Determine the founding conditions for the proposed development,

- Identify any potential problematic soil (active, collapsible, erosive),

- Determine the suitability of the subsoil materials across the site for construction use,

- Determine the presence of potentially problematic geotechnical conditions and

recommendations relevant to the proposed development (i.e. water table issues,

etc.).

We confirm that the investigation was carried out as per our cost estimate and work

proposal letter Ref. 91 dated 26 February 2018.th

mailto:[email protected]

Ref. 32225 Inprodev (Pty) Ltd Umbumbulu Shopping Centre Page ¹ 2

Our subsequent findings, geotechnical assessment and recommendations for development

are set out in this report.

2. INFORMATION SUPPLIED AND PROPOSED DEVELOPMENT

Information supplied to Drennan Maud (Pty) Ltd included a Google Earth satellite image

drawing showing the location of the proposed development as well as a surveyed drawing

of the site carried out by MHP Geomatics (Drawing No. Mbongwe Shopping Centre).

At the time of publishing the report, no details had been provided regarding the layout,

loading or earthworks of the proposed shopping centre development. The geotechnical

investigation was required for the developments Spatial Planning and Land Use

Management Act (SPLUMA) application.

3. SITE DESCRIPTION

The proposed shopping centre, which is located within the town of Umbumbulu, is

positioned in a shallow basinal valley line which naturally slopes/drains gently in a

southwesterly direction across the R603 road.

The investigated site is bounded to the northeast by 300006 Street, to the southeast by

residential properties, to the southwest by the main R603 road and to the northwest by the

local service station and tribal court as shown in Plate 1 below.

Plate 1 : Locality plan showing the position of the proposed development relative to

Umbumbulu Town.


Previous levelling of the site in the form of cut and fill bulk earthworks has been carried out

resulting in the majority of the site being a single level platform which has a very gentle fall

to the southwest (Refer Plate 2 & Plate 3).

Plate 2 : Photograph of the previously levelled site. Viewing Direction - South.

Plate 3 : Photograph of the previously levelled site taken from the top of the 5m high cut

embankment with the service station and tribal court in the background. Viewing Direction -

Northwest.


Based on the Google Earth Time Slider Tool, the central northeastern half of the site had

been cut to approximately 2.0m below natural ground level prior to 2002 as evident in the

300006 Street cut embankment(Refer to the top right background portion of Plate 3) with

a number of small single storey structures being present in the southwestern portions of the

site. During 2015, these structures were demolished with the central northeastern portions

being reworked/levelled; the southwestern portions being filled and the southern corner of

the site being cut to form a single large platform area.

As a result, a maximum of 3.5m of filling was carried out in the southwestern central valley

line portion adjacent and immediately northeast of the R603 road (Refer Plate 4).

Furthermore, the southwestern corner of the site had been cut to a maximum 4.0 to 6.0m

below natural ground level as evidenced by the southwestern cut embankment (Refer Plate

3).

Plate 4 : Photograph showing the 2.0 to 3.5m high fill embankment to the right and above the

cleared track with the R603 road fill embankment on the right. Viewing Direction - Northwest.

A number of derelict partially demolished single storey structures are present on narrow

terraced platforms in the eastern portions. It was not clear at the time of the investigation

whether this area will be developed during the construction of the shopping centre.

4. FIELD WORK

The field investigation was carried out on the 29 March 2018 and comprised theth

mechanical excavation of inspection pits, Dynamic Cone Penetrometer (DCP) testing and

material sampling. The approximate positions of the field tests are shown on the site plan,

DWG 32225/01.

Details of the field testing are provided overleaf.


4.1 Inspection Pits: IP 1 - 13

A total of thirteen inspection pits, designated IP 1 to IP 13, were mechanically excavated

using a TLB to investigate the nature of the underlying subsoils. The inspection pits were

excavated to a maximum depth of 4.10m without refusal.

The subsoils exposed in the inspection pits were examined and logged by an Engineering

Geologist familiar with the procedures of soil logging in terms of the guidelines for Soil And

Rock Logging in South Africa, 2 Impression 2002, edited by A.B.A Brink and R.M.H Bruin.nd

This included recording the following parameters.

C For soil : Moisture conditions, colour, consistency, structure (where applicable), soil

texture and origin.

The detailed inspection pit logs are presented in Appendix A of this report.

4.2 Dynamic Cone Penetration Tests: DCP 1 - 12

A total of twelve Dynamic Cone Penetrometer (DCP) tests, designated DCP 1 to DCP 12

were conducted across the site.

The aim of the DCP testing was to obtain an indication of the consistency of the subsoil

underlying the site at shallow to moderate depths. The DCP tests were carried out to a

maximum refusal depth of 7.5m below Existing Ground Level (EGL) on very dense/hard

material or on a ferruginised gravel layer or possibly on bedrock material.

The results of the DCP test probes are presented graphically within Appendix B of this

report.

For ease of DCP interpretation, an empirically derived table relating blow counts/300mm

penetration to soil consistency is presented below. It should be noted that the table is based

on the Drennan Maud probe and should be used as a guide only.


Table 1 : Subsoil Consistency Inferred from the DCP Test Results

Non Cohesive Soils Cohesive Soils

¹ of blows/300 mm

Penetration

Subsoil

Consistency

¹ Of blows/300

mm Penetration

Subsoil

Consistency

<8 Very loose <4 Very soft

8 - 18 Loose 4 - 8 Soft

19 - 54 Medium dense 8 - 16 Firm

55 - 90 Dense 16 - 24 Stiff

>90 Very dense 25 - 54 Very stiff

>54 Hard

4.3 Material Sampling

The prevailing materials on site were sampled from the inspection pits and returned to

Thekwini Soils Laboratory in Durban for testing. The materials tests conducted thereon

included Full Indicator, Mod AASHTO Density and CBR testing.

A schedule of the laboratory samples and tests conducted on each is included in Table 2.

Table 2 : Laboratory Testing Schedule

IP Description Depth (m)Laboratory Test

Indicator Mod CBR

9 Fill 0.00 - 0.80 T T T

2

Residuum

2.00 - 4.00 T T T

3 0.00 - 4.00 T T T

4 0.50 - 2.10 T T T

10 1.80 - 3.80 T T T

The laboratory test results summary tables as well as graphical representation of the

grading analyses are included within Appendix C of this report and are discussed in detail

under Section 6 below.


5. SITE GEOLOGY

5.1 General

From examination of the 1:250 000 Geological Series plan of the area, 3030 Port

Shepstone, published by the Geological Survey coupled with the field investigation it is

evident that the geology underlying the site comprises deeply weathered Ordovician aged

Natal Group sandstone along with their respective residual and colluvial materials derived

from the in-situ weathering thereof. Bulk fill material is present in previously developed

portions of the site with a thin of surface capping fill being present across the majority of the

site.

5.2 Fill

The central longitudinal southwest to northeast portions of the site has a reworked fill

surface capping horizon in both cut and filled portions. This surfacing capping fill material

is derived from in-situ residual material and generally comprises a brownish red to orange

red, firm to stiff, sandy silty clay which extends to depths ranging between 0.5 and 1.0m

below platform level.

In the southwestern portions, poorly engineered bulk filling is present to depths of up to

3.5m below platform level. The bulk fill material, which was encountered in IP’s 1/2/5

generally comprises a dark grey, firm silty sandy clay to sandy silty clay which contains up

to 40% foreign material. The foreign material is highly variable and includes, but is not

limited to, gravel to boulder sized rubble fragments, plastic, textiles, glass, ferrous items,

solid wood and organic material and contains localised voids.

It is inferred that the poorly engineered bulk fill material was sourced from the upper

colluvial material along with the demolished southwestern structures during the 2015

earthworks operation.

5.3 Hillwash/Colluvium

In-situ hillwash/colluvial material was encountered at surface level in IP’s 4/8/10/11 and was

encountered directly below the surface capping fill material in IP’s 5/6/7/9. The

hillwash/colluvial material was observed to be generally uniform and can be described as

a dark brown, firm to stiff, intact, silty clay. The material ranged between 0.4 and 1.7m in

thickness.

5.4 Residual Sandstone

Underlying the above materials, and locally at surface level, residual sandstone material is

present. The residual sandstone material varies in colour between orange brown and

brownish red with lighter coloured horizons comprising orange banded yellow pink white

and red.


The residual materials consistency was generally observed to be firm to stiff containing soft

horizons becoming very stiff with depth and varied in compositions between a slightly sandy

very silty clay and a clayey very silty sand. The residual sandstone material was observed

to depth in excess of 4.0m in the inspection pits and is inferred to depths of up to and

possibly greater than 5.0 to 7.5m below EGL when considering the DCP test results.

5.5 Lateritic Horizons

The relatively flat terrain characterising the elevated Umbumbulu area is a distinguishing

feature of the Pan-African planation surface. This ancient erosion surface is characterised

by an upper pedogenic horizon (known as ‘duricrust’) which in the Umbumbulu area is of

typical lateritic (ferricrete gravels) composition. These ferricrete horizons are a result of a

previously fluctuating groundwater table during the period of the ancient erosion surface

which reworked the residual sandstones resulting in variable cemented gravel horizons

within the residuum.

Localised trace ferricrete nodules and gravels were observed in a few of the inspection pits

and are therefore not foreseen to be of major consequence in the upper 4.0m profile across

the site. Where encountered, these horizons comprised a stiff to very stiff, silty clay matrix

containing up to 40 to 50% strongly cemented coarse gravel sized ferricrete nodules with

the TLB starting to struggle through this material.

5.6 Bedrock

No sandstone bedrock was encountered in the inspection pits excavated across the site.

Deeply weathered sandstone bedrock is likely to occur at depths in excess of the DCP

refusal depths of 5.0 to 7.5m below EGL.

Although not encountered, the sandstone bedrock underlying is anticipated to be deeply

weathered with a gradational contact occurring between the residual sandstone and

completely weathered sandstone. The gradual change in density and clay content as well

as the presence of bedding within the material is likely to be the most noticeable difference

between the two materials.

The depth to weathered bedrock may vary randomly across the site as a result of the

depositional environment in which the sandstones formed, subsequent erosion as well as

the composition of the sandstones resulting in localised erratic soft spots.

5.7 Groundwater

Groundwater seepage was encountered in IP 1 and IP 2 at depths of 2.8 and 2.0m

respectively. Based on the previous geomorphology/topography of the site, natural

groundwater flow will in all likelihood flow towards the previous central southwest plunging

drainage line.


The presence of mottling and localised ferricrete nodules/gravels and horizons further

demonstrates the presence of a seasonal perched water table in the more sandy layers

above less permeable residual clays.

6. LABORATORY RESULTS

6.1 Material Classification Test Results

The grading analysis and density results for the respective materials sampled on site are

included in Table 3 overleaf for ease of reference. The results are also summarised in the

Laboratory Test Summary Tables included in Appendix C of this report along with graphical

representation of the materials analysis.


Table 3 : Summary of Laboratory Test Results (Grading Analysis, Atterberg Limits, Mod AASHTO, Optimum Moisture

Content, CBR and Respective Classifications)

IP Depth (m)

Particle Size (%) Atterberg Limits (%)

MDD

(kg/m )3

OMC

(%)

CBR VALUES Revised

US

Class

TRH

14

1985Clay Silt Sand Gravel Cobble LL PI LSCompaction MDD (%) Swell

(%)90 93 95 98 100

FILL MATERIAL

9 0.00 - 0.80 26.1 19.1 53.1 1.7 0.0 26.8 5.4 2.0 1712 14.5 7 11 15 18 20 0.45 A - 4 G8

RESIDUAL SANDSTONE

2 2.00 - 4.00 24.8 11.7 53.4 1.1 0.0 31.7 0.0 0.0 1771 14.7 4.7 6 6.9 11 14 0.00 A - 4 G10

3 0.00 - 4.00 16.6 26.6 54.7 2.1 0.0 33.7 10.9 3.3 1786 14.3 5 8 10 11 12 0.47 A - 6 G9

4 0.50 - 2.10 33.2 10.0 32.4 24.4 0.0 34.8 7.6 2.7 1731 17.0 4 5 5.9 6.7 7.4 0.18 A - 4 G10

10 1.80 - 3.80 9.1 25.0 65.0 0.9 0.0 25.4 5.6 1.3 1811 12.9 11 12 12 13 14 0.31 A - 2 - 4 G8


7. GEOTECHNICAL ASSESSMENT

7.1 Site Stability

No evidence of significant previous or on going slope instability was observed across the

site during the field investigation due to the level nature of the site.

However, the 2.0 to 3.5m high poorly engineered fill embankment which contains abundant

foreign material and is prone to subsurface drainage groundwater flow, may present future

stability issues once the soil binding vegetation is removed and the embankment is loaded

by the proposed development. Recommendations in this regard are given in Section 8.1.1

below.

Furthermore, the existing 4.0 to 6.0m high steep cut embankment in the southern corner

of the site is observed to exceeds the recommended cut batters given in Section 8.1.1.

Recommendations in this regard are further given in Section 8.1.1 below.

Notwithstanding the above, localised instability could be induced should any injudicious

cutting and/or filling take place during the construction of the proposed development.

7.2 Subsoil Activity

Active soils are those that will undergo volume change with seasonal fluctuations in the

materials in-situ moisture content (i.e. swell when wet and shrink when dry).

Based on van der Merwe’s (1964) ‘potential swell prediction’ chart, the fill material and

residual sandstone materials sampled on site have a low to moderate heave potential of 2%

and less.

Due to the limited amount of sampling and coverage of the site, it is possible for more active

soils to be encountered locally upon excavation.

7.3 Subsoil Seepage

As discussed in Section 5.7, groundwater seepage was encountered in the inspection pits

which were excavated in the area of the previous central southwest plunging drainage line

(i.e. IP 1 and IP 5).

These seepage prone areas occurring in the previous naturally low lying portions of the site

may be a result of the seasonal groundwater flow draining the higher lying areas and are

unlikely to be short-lived.


7.4 Excavatability

“Soft” excavation as classified by SABS 1200 D is expected in the fill and residual

sandstone materials to depths ranging between 5.0 to 7.5 below EGL in open excavation.

Due to the lack of deep geotechnical data,‘intermediate’ becoming ‘hard’ excavation are

conservatively inferred beyond these depths.

7.5 Material Suitability and Construction Materials

From the results of the laboratory testing and previous experience with the encountered

materials the following may be deduced:

The poorly engineered bulk fill material is unlikely to meet the requirements of G10 material

(after TRH 14 1985) and is not considered suitable as engineered fill due to the presence

of abundant foreign material. Where encountered, this material should be boxed out to

spoil.

According to the laboratory test results, the residuum derived surface capping fill material

met the requirements of G8 (after TRH 14 1985). However, due to its clay and silt content

as well as the required high optimum moisture content which is difficult to

accurately/practically achieve during construction, it is recommended that this material be

considered suitable as an existing platform subgrade surface only. Should new engineered

fill or subgrade material for road or pavement layerworks be required, it is advised that this

material not be considered suitable for reuse.

The hillwash/colluvial material is unlikely to meet the requirements of G10 material and is

not considered suitable as engineered fill. Due to its organic nature it is recommended that

the material be stockpiled for later landscaping usage.

According to the laboratory test results, the in-situ residual sandstone material ranges

between G8 and G10 material (after TRH 14 1985). Similarly to the residuum derived

surface capping fill, it is recommended that this material be considered suitable as an

existing platform subgrade surface only.

Considerable volumes of granular material for use as engineered fill, selected layer,

subbase and base material is unlikely to be encountered on site and thus will need to be

imported from a local quarry source.

7.6 Settlement Analyses

From the DCP results it is evident that the bearing capacity of the subsoils at a depth of

1.5m below EGL is likely to vary between 80 kPa and 150 kPa.


However, it must be understood that in the subsoils underlying the site, the allowable

bearing pressure is likely to be determined by tolerable settlement and not bearing capacity

failure. In this regard settlement analyses were carried out to obtain an indication of the

likely settlement of normal strip footings and column base pad foundations using realistic

DCP’s across the site.

No indication of loads, structure size nor height have been given for the shopping centre.

As such, an inferred load range has been used in the analyses. The results of the

settlement analyses are summarised in Table 4 and Table 5 respectively.

Table 4 : Inferred Settlement for Shallow Strip Foundations

Load

(kN)

Bearing

Pressure

(kPa)

Strip Width

(m)

Expected Settlement (mm)

DCP 2 DCP 7 DCP 10

75 110 0.7 11 9 9

110 160 0.7 15 14 13

150 215 0.7 21 18 17

The results for the inferred strip footing settlement analyses indicate that the likely

settlements will range between about 9 mm and 11 mm for a load of 75 kN and a bearing

pressure of 110 kPa to between 18mm and 21mm for a load of 150 kN and a bearing

pressure of 215 kPa for strip footings for the proposed structures.

Table 5 : Inferred Settlement for Shallow Column Base Pad Foundations

Load

(kN)

Bearing

Pressure

(kPa)

Column Base

Pad Dimensions

(m)

Expected Settlement (mm)

DCP 2 DCP 7 DCP 10

150 150 1 X 1 9 8 9

340 150 1.5 X 1.5 14 13 12

600 150 2 X 2 17 16 15

940 150 2.5 X 2.5 21 20 18

The results for the inferred column base pad settlement analyses indicate that the likely

settlements will range between about 8 mm to 9 mm for a load of 150 kN to between 18

mm and 21 mm for a load of 940 kN at a bearing pressure of 150 kPa for column base pad

foundations for the proposed structures.

Additionally, it must be noted that differential settlement may be high due to the larger

footprint area of the structure across variable soil densities as seen in the DCP test results

as well as the active clayey composition of the subsoils at shallow founding level.


7.7 Founding Conditions

Based on the inspection pit profiles as well as the DCP test results, founding conditions

across the site are considered moderately favourable at shallow depths for lightly loaded

single storey structures but is considered poor for heavily loaded single and double storey

structures.

8. GEOTECHNICAL RECOMMENDATIONS

8.1 Earthworks

Although no indication of platform levels have been provided, minimal earthworks are

expected to be necessary for the proposed shopping centre across the generally level site.

Based on the above, general recommendations with regard to earthworks are given below.

Should considerable cutting or filling be proposed for the site, the earthworks

recommendations will need to be reassessed.

8.1.1 Cutting

On initial cutting, the clayey fill and in-situ materials may stand at steep batters, due to the

temporary cohesive strength imposed by the partially saturated conditions at a natural

moisture content. Such banks will however fail in time as they loose their temporary

cohesive strength, either by drying out or by becoming saturated.

Cut embankments in all the generally clayey materials on site should be restricted to a

slope batter of 1:75 (30E). For temporary excavations where required, batters may be

increased to a maximum of 1:1.5 (33E) at the discretion of the Engineer.

Temporary service or foundation trenches greater than 1.2m depth must be battered back

to a maximum of 1:1.75 (30°) or alternatively shored to ensure safe working conditions.

Where the above recommended batters cannot be accomplished, excavations should be

suitably shored on a temporary basis during construction and adequately retained on a

permanent basis post construction.

As mentioned in Section 7.1, the 4.0 to 6.0m high cut embankment in the southern corner

of the site exceeds the recommended maximum batters given above. As such, it is

recommended that the embankment be further cut to meet the recommended maximum

cut batters. The Engineer may need to assess whether this will encroach into the

neighbouring residential property and whether boundary relaxation is possible. Should

space not allow for further cutting back to acceptable batters, suitably designed lateral

support is recommended for the embankment.


Cut-off drainage is recommended above cuts with backslopes to avoid stormwater

adversely affecting the cut stability.

Where existing or previously existing large sized trees are marked by their remaining

stumps, the entire stump including the entire bulb of roots must be removed and the void

be backfilled in suitably compacted layers, as required for general filling, to final ground

level. Similarly, where existing structures are to be demolished and removed, the entire

structure and foundation must be removed and suitably backfilled.

In regard to the existing poorly engineered bulk fill material occurring in the southwestern

central portions (IP’s 1/2/5), it is recommended that these materials be excavated out for

spoil and replaced with suitably compacted and appropriately founded granular material as

required for engineered filling (See Section 8.1.2 below).

In addition, it is recommended that all excavations/cuts be frequently assessed by a

Geotechnical Engineer or Engineering Geologist during the earthworks operation.

8.1.2 Fill Embankments and Backfilling

Prior to the placement of any fills, the natural ground must be stripped of all vegetation.

All fills should be constructed of suitable granular material (G10 or better) and placed in

layers of maximum 300mm loose thickness and compacted to a minimum of 95% Mod

AASHTO density prior to the placement of the next layer to minimise post construction

settlement and potential stability problems. Furthermore, to ensure proper and uniform

compaction across fill platforms the maximum fill particle size should be no greater than two

thirds the layer thickness.

Where the natural gradient locally exceeds 10E, or where new engineered fill material is to

replace the existing poorly engineered bulk fill material, these fills should be benched into

the natural slope (firm to stiff subsoils) in order to maintain the long term stability of the fill

embankment.

For preliminary design purposes, general fill embankments should not exceed a maximum

slope batter of 1:2 (26°). However, batters of engineered fills may be steepened to 1:1.75

(30°) depending on the proposed fill height.

Back-fill behind retaining structures and service trenches as well as where tree stumps and

foundations have been removed should be placed and spread in thin layers, approximately

100 to 150mm loose thickness, with each layer being compacted to at least 95%, but

preferably 98% of the material Mod AASHTO density prior to construction of the next layer.

All fill embankments must be adequately vegetated or paved as soon as possible after

construction to limit the potential for erosion. Where the recommended batters cannot be

accommodated, permanent lateral support should be incorporated.


8.2 Founding

At the time of publishing this report, no structural layout, number of storeys or proposed

loads had been made available for the proposed shopping centre. As such, a range of

preliminary founding solutions have been provided.

8.2.1 Shallow founding

Depending on the proposed loads of the structure and provided the proposed shopping

centre is to comprise a single storey structure and the inferred total and differential

settlement amounts fall within tolerable limits with regards to the structure, the proposed

shopping centre structure can be supported on strip footings or ground beams spanning

column bases.

However, in this regard we recommend the following;

- A maximum allowable bearing pressure of 150 kPa is applied for the design of the

shallow foundations.

- The foundations are taken through all fill and hillwash/colluvial materials to a

minimum depth of 1.2m below original ground level into in-situ residual material

across the entire footprint of the proposed structure.

- The clayey residual founding material should be spiked and thoroughly watered for

a period of at least 24 hours immediately prior to casting of the surface bed. This

will allow the clayey soils to swell, thus reducing heave and consequent severe

cracking of the structure.

- All floor slabs should be isolated from all walls, columns and foundations to allow

for any potential settlement that may still occur with time.

- Articulation joints should be incorporated into the design of the structures to allow

for potential differential settlement/heave that may occur and prevent potential

cracking of the structure.

8.2.2 Deep Founding

Should the proposed loads of the structure be such that tolerable settlement amounts are

exceeded, the required base sizes to carry the loads are deemed impractical, or the

proposed shopping centre be two storeys or greater, we recommend that a deep founding

solution is adopted. In this regard ground beams spanning pile foundations would be

suitable. Due to the soft consistencies of the upper soils and a shallow groundwater table

in the central portions, Continuous Flight Auger (CFA) piles are likely to be the most

suitable piled solution.


The advantages of piled foundations are:

- Differential settlements will be negligible, if properly designed

- Piles can be rapidly installed and thus reduce the time required for construction of

the foundations.

- The necessity to excavate deep founding trenches along with their lengthy time

periods are eliminated.

- The use of piles eliminates shoring requirements of deep foundation excavations.

Due to the nature of the investigation and scope of works, the exact depth of bedrock is

unknown and may be present at depths ranging between 5.0 to 7.5m below EGL and

possibly greater. As such, the piles should be designed as end bearing piles socketed into

the weathered sandstone bedrock. The maximum allowable pile loads for CFA piles should

be based on 5,0MPa of the pile shaft cross-sectional area for piles socketed into the

weathered sandstone bedrock.

From observations on site and previous experience it is likely that the sandstone bedrock

is deeply weathered and it may not be practical to achieve 5MPa end bearing on the piles

and it will be necessary to design the piles as a combination of end bearing and friction.

Based on the above anticipated variability, it is recommended that pile lengths be re-

measured on installation. Should a fixed price tender be opted for, it would be advisable for

the tenderers to carry out test auger holes to satisfy themselves on the pile lengths and

subsoil profile/rock hardness at depth.

All ground floor walls should be carried on reinforced ground beams spanning between the

pile caps. All ground floor slabs should be isolated from all walls and placed on the in-situ

ground subject to compaction.

It is recommended that once the piling layout and earthworks have been finalized, a

comprehensive pile design be carried out by a Geotechnical Professional familiar with the

design of piled foundations. It must be understood that the effects of any downdrag induced

by settlement of new fills must be taken into consideration. A Geotechnical Professional

should be involved during the pile installation to confirm the auger pile lengths and socket

depths during the piling operation.

Drennan Maud (Pty) Ltd is able to carry out the pile design at competitive prices, if required.

Furthermore, should the Client wish to establish the bedrock levels below the site and

determine the most appropriate piled founding solution, Drennan Maud (Pty) Ltd is able to

carry out a deep investigation comprising the drilling of test auger holes or alternatively

drilling of geotechnical boreholes at a competitive price.


8.3 Surface Drainage

Stormwater from all roofed and paved areas must be piped or carried in surface drains to

discharge into a suitable stormwater system.

After construction, all platforms should be suitably graded to facilitate storm water runoff

and to prevent the ponding of storm water on surfaces adjacent to structures. No

uncontrolled runoff over cut or fill embankment should be allowed as this may cause

erosion of the banks affecting the stability thereof.

8.4 Subsoil Drainage

Seepage may occur during periods of rainfall in cuts. Control of seepage through the

installation of subsoil drains may be necessary in these areas.

Control of seepage by the installation of subsoil and surface drains behind and at the top

of any retaining structures respectively may be necessary if such subsoil seepage is

encountered.

8.5 Retaining Structures

Should any retaining structures be required on site, these should be designed by a

Structural Engineer familiar with such structures.

Damp proofing to the retaining structures is considered essential. It is further recommended

that subsoil drains are installed behind all retaining walls, in addition to the standard damp

proofing/tanking. Backfill behind retaining walls should comprise free draining coarse sands

above the heel subsoil drains.

The design of retaining structures must be based on materials having the following slightly

conservative strength parameters;

• angle of internal friction (i), 28E

• cohesion (c) 0 kPa

• bulk density 1800 kg/m3


9. CONCLUSION

Based on the results of the investigation we consider that the site is suitable for the

development of a shopping centre provided that the development is carried out in terms of

the recommendations given in this report.

However, we recommend that a detailed geotechnical investigation of the site be carried

out once the final design and layout of the shopping centre is available to confirm and

supplement the results of this investigation.

We trust that this meets with your immediate requirements into this matter and will be pleased to

furnish you with any further information you may require.

Yours faithfully

DRENNAN MAUD (PTY) LTD

M J HADLOW Pr.Sci.Nat. KYLE GORDON Eng. Geol.

Encls : Appendix A - Soil Profiles

Appendix B - DCP Results

Appendix C - Laboratory Test Results

DWG 32225/01 - Site Plan

/kg/kc

APPENDIX A

SOIL PROFILES


Geotechnical Engineers & Engineering Geologists

2.80m

INPRODEV


HOLE No: IP 1

Sheet 1 of 1

HOLE No: IP 1

Sheet 1 of 1

JOB NUMBER: 32225JOB NUMBER: 32225

0.80

0.00

3.30

4.10

Moist, brownish red, firm to stiff, slightly sandy very silty CLAY – (Fill Surfacing Derived

From Residuum)

Moist becoming wet, dark grey, firm, silty sandy CLAY containing 20-40% foreign

material – (Poorly Engineered Bulk Fill). Foreign material comprises gravel to boulder

sized rubble fragments, plastic, textiles, glass, wood and ferrous items.

Moist, brownish red, stiff, intact, slightly sandy very silty CLAY – (Residual Sandstone)

Scale1:25

NOTES

1) No refusal

2) Groundwater seepage encountered at 2.80m

3) Side wall collapse from 0.90m

4) Gradual contact between residual and weathered sandstone

CONTRACTOR :MACHINE :

DRILLED BY :PROFILED BY :

TYPE SET BY :SETUP FILE :

NATLBNAKG

kcDMPSP.SET

INCLINATION :DIAM :DATE :DATE :

DATE :TEXT :

NANANA29/03/2018

10/05/18 16:03..C:\DOTIN\SPMASTER.DOC

ELEVATION :X-COORD :Y-COORD :

---

dot.PLOT 5008 J&W D06B DRENNAN MAUD & PARTNERS

HOLE No: IP 1HOLE No: IP 1

1

2

3

4

SAMPLE DEPTH(m)



AASHTO

CBR

INPRODEV


HOLE No: IP 2

Sheet 1 of 1

HOLE No: IP 2

Sheet 1 of 1


2.00

0.00

4.10

Moist, dark brown to dark grey, firm, slightly sandy silty CLAY containing

approximately 5-10% foreign material – (Poorly Engineered Bulk Fill). Foreign material

includes plastic and textiles.

Moist, orange brown, firm, intact, silty very clayey SAND – (Residual Sandstone)

Scale1:25

NOTES

1) No refusal

2) No groundwater seepage

3) No side wall collapse

4) Residuum sampled between 2.00 and 4.10m for Full Indicator (I), Mod AASHTO

Density (M) and CBR (C) lab testing




NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

4

IMC

SAMPLE DEPTH(m)



AASHTO

INPRODEV


HOLE No: IP 3

Sheet 1 of 1

HOLE No: IP 3

Sheet 1 of 1


4.00

0.00Moist, orange mottled and banded pink yellow and red, stiff, intact, clayey sandy SILT

containing horizons of silty sand – (Residual Sandstone)

Scale1:25

NOTES

1) No refusal

2) Inspection pit positioned in 3.0 to 4.0m of cut








NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

4

IMC

SAMPLE DEPTH(m)



AASHTO

CBR

INPRODEV


HOLE No: IP 4

Sheet 1 of 1

HOLE No: IP 4

Sheet 1 of 1


0.50

0.00

2.10

4.10

Moist, dark brown, firm, intact, silty CLAY – (Colluvium)

Moist, brownish red, firm to stiff, intact, slightly gravelly very sandy CLAY – (Residual

Lateritic Sandstone)

Moist, light orange blotched white pink and yellow, firm to stiff, intact, sandy SILT –

(Residual Sandstone)

Scale1:25

NOTES

1) No refusal








NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

4

IMC

SAMPLE DEPTH(m)



2.00m

INPRODEV


HOLE No: IP 5

Sheet 1 of 1

HOLE No: IP 5

Sheet 1 of 1


1.20

0.00

1.80

2.40

3.70

4.00

Moist, dark brown to dark grey, firm, slightly sandy silty CLAY containing

approximately 5-10% foreign material – (Poorly Engineered Bulk Fill). Foreign material

includes plastic and textiles.


From Residuum)


Moist, orange light brown, firm to stiff, intact, very silty CLAY – (Residual Sandstone)

Moist, light brown mottled orange red and grey, stiff to very stiff, intact, silty CLAY

matrix containing approx. 40-50% strongly cemented gravel sized ferricrete nodules –

(Residual Lateritic Sandstone)

Scale1:25

NOTES

1) No refusal. However, TLB struggling in lower material

2) Slight groundwater seepage at 2.00m





NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

4

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 6

Sheet 1 of 1

HOLE No: IP 6

Sheet 1 of 1


0.50

0.00

0.60

1.60

3.90


From Residuum)

Slightly moist, yellow white, medium dense, slightly silty SAND – (Fill Derived From

Residuum)


Moist, orange brown, firm to stiff, intact, sandy silty CLAY – (Residual Sandstone)

Scale1:20

NOTES

1) No refusal






NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 7

Sheet 1 of 1

HOLE No: IP 7

Sheet 1 of 1


0.50

0.00

1.80

3.60

4.00


From Residuum)



Moist, light grey, firm to stiff, intact, very sandy CLAY – (Residual Sandstone)

Scale1:25

NOTES

1) No refusal


3) No sidewall collapse




NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

4

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 8

Sheet 1 of 1

HOLE No: IP 8

Sheet 1 of 1


0.90

0.00

2.70

4.10


Moist, brownish red, firm to stiff, intact, slightly sandy CLAY – (Residual Sandstone


Scale1:25

NOTES

1) No refusal






NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

4

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 9

Sheet 1 of 1

HOLE No: IP 9

Sheet 1 of 1


0.80

0.00

2.50

3.90


From Residuum)



Scale1:20

NOTES

1) No refusal



4) Fill material taken between 0.00 and 0.80m for Full Indicator (I), Mod AASHTO





NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

IMC

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 10

Sheet 1 of 1

HOLE No: IP 10

Sheet 1 of 1


0.40

0.00

2.10

3.80


Moist, brownish red, firm to stiff, intact, slightly sandy CLAY – (Residual Sandstone)

Moist, orange banded pink yellow and white, firm to stiff, intact, very silty SAND –


Scale1:20

NOTES

1) No refusal



4) Residual material taken between 2.10 and 3.80m for Full Indicator (I), Mod AASHTO





NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3 IMC

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 11

Sheet 1 of 1

HOLE No: IP 11

Sheet 1 of 1


0.80

0.00

2.10

3.00

3.80




Moist, light grey, firm to stiff, intact, very sandy CLAY – (Residual Sandstone)

Scale1:20

NOTES

1) No refusal






NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 12

Sheet 1 of 1

HOLE No: IP 12

Sheet 1 of 1


1.60

0.00

3.90


Moist, light orange blotched white pink and yellow, firm to stiff, intact, sandy SILT –


Scale1:20

NOTES

1) No refusal






NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

SAMPLE DEPTH(m)



INPRODEV


HOLE No: IP 13

Sheet 1 of 1

HOLE No: IP 13

Sheet 1 of 1


1.10

0.00

3.80

4.10


Moist, pink orange and white, firm to stiff, intact, slightly sandy silty CLAY – (Residual

Sandstone)


Scale1:25

NOTES

1) No refusal






NATLBNAKG

kcDMPSP.SET


DATE :TEXT :

NANA29/03/2018



---



1

2

3

4

SAMPLE DEPTH(m)

APPENDIX B

DYNAMIC CONE PENETROMETER TEST

RESULTS

Dynamic Cone Penetrometer

Test No. : 1

Project : UMBUMBULU SHOPPING CENTRE

Client: INPRODEVDate: 10 APRIL 2018 Remarks: -

Test Location: UMBUMBULU -

Date of Test: 29 MARCH 2018 Depth Interval (m) : 0.3

Depth Count

(m) Blows/0.3m

0 0

-0.3 25

-0.6 20

-0.9 19

-1.2 48

-1.5 35

-1.8 36

-2.1 28

-2.4 22

-2.7 14

-3.0 18

-3.3 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

Reference No. : 32225 Drennan Maud (Pty) Ltd

Fig. No. B1

Note: DCP Blow Count equals the number of blows of a 10kg hammer dropping 450mm required to drive a 25mm diameter 60o

cone a distance of 300mm.

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)

Blow Count per 300mm

Blow Count vs Depth

Hard Refusal


Test No. : 2





Depth Count

(m) Blows/0.3m

0 0

-0.3 8

-0.6 18

-0.9 32

-1.2 13

-1.5 12

-1.8 14

-2.1 12

-2.4 13

-2.7 17

-3.0 15

-3.3 12

-3.6 13

-3.9 17

-4.2 16

-4.5 17

-4.8 19

-5.1 13

-5.4 9

-5.7 16

-6.0 21

-6.3 25

-6.6 32

-6.9 67

-7.2 91

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B2



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal

Hard Refusal


Test No. : 3





Depth Count

(m) Blows/0.3m

0 0

-0.3 17

-0.6 33

-0.9 37

-1.2 35

-1.5 28

-1.8 32

-2.1 48

-2.4 61

-2.7 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B3



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 4





Depth Count

(m) Blows/0.3m

0 0

-0.3 13

-0.6 5

-0.9 8

-1.2 9

-1.5 9

-1.8 10

-2.1 7

-2.4 6

-2.7 15

-3.0 23

-3.3 37

-3.6 35

-3.9 37

-4.2 30

-4.5 28

-4.8 36

-5.1 23

-5.4 48

-5.7 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B4



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 5





Depth Count

(m) Blows/0.3m

0 0

-0.3 15

-0.6 20

-0.9 39

-1.2 18

-1.5 16

-1.8 10

-2.1 10

-2.4 5

-2.7 5

-3.0 16

-3.3 18

-3.6 34

-3.9 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B5



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 6





Depth Count

(m) Blows/0.3m

0 0

-0.3 14

-0.6 10

-0.9 9

-1.2 20

-1.5 36

-1.8 24

-2.1 16

-2.4 22

-2.7 23

-3.0 27

-3.3 21

-3.6 21

-3.9 22

-4.2 13

-4.5 15

-4.8 20

-5.1 18

-5.4 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B6



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 7





Depth Count

(m) Blows/0.3m

0 0

-0.3 13

-0.6 25

-0.9 20

-1.2 29

-1.5 28

-1.8 37

-2.1 28

-2.4 8

-2.7 5

-3.0 5

-3.3 3

-3.6 13

-3.9 14

-4.2 12

-4.5 17

-4.8 23

-5.1 19

-5.4 31

-5.7 52

-6.0 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B7



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 8





Depth Count

(m) Blows/0.3m

0 0

-0.3 15

-0.6 23

-0.9 22

-1.2 10

-1.5 14

-1.8 16

-2.1 12

-2.4 15

-2.7 24

-3.0 48

-3.3 63

-3.6 27

-3.9 25

-4.2 32

-4.5 30

-4.8 56

-5.1 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B8



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 9





Depth Count

(m) Blows/0.3m

0 0

-0.3 21

-0.6 26

-0.9 11

-1.2 10

-1.5 10

-1.8 8

-2.1 6

-2.4 5

-2.7 7

-3.0 21

-3.3 22

-3.6 21

-3.9 39

-4.2 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B9



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 10





Depth Count

(m) Blows/0.3m

0 0

-0.3 14

-0.6 7

-0.9 9

-1.2 6

-1.5 5

-1.8 7

-2.1 9

-2.4 13

-2.7 13

-3.0 12

-3.3 29

-3.6 20

-3.9 24

-4.2 13

-4.5 41

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B10



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 11





Depth Count

(m) Blows/0.3m

0 0

-0.3 10

-0.6 11

-0.9 18

-1.2 19

-1.5 11

-1.8 13

-2.1 9

-2.4 18

-2.7 22

-3.0 21

-3.3 25

-3.6 25

-3.9 33

-4.2 35

-4.5 38

-4.8 41

-5.1 38

-5.4 29

-5.7 36

-6.0 39

-6.3 46

-6.6 64

-6.9 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B12



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal


Test No. : 12





Depth Count

(m) Blows/0.3m

0 0

-0.3 18

-0.6 19

-0.9 6

-1.2 22

-1.5 26

-1.8 32

-2.1 47

-2.4 35

-2.7 31

-3.0 36

-3.3 42

-3.6 39

-3.9 40

-4.2 47

-4.5 55

-4.8 58

-5.1 100

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0

- 0


Fig. No. B12



-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

0 10 20 30 40 50 60 70 80 90 100

Rela

tive D

epth

(G

.L =

0 m

)


Blow Count vs Depth

Hard Refusal

APPENDIX C

LABORATORY TEST RESULTS

Job Description:Job no.: 8661Date: 20-04-2018Lab no. 04079 04080 04081 04082 04083 - - - - -Location IP.2 IP.3 IP.4 IP.9 IP.10 - - - - -Depth 2 - 4.0 0 - 4.0 0.5 - 2.1 0.0 - 0.8 1.8 - 3.8 - - - - -Description Residuum Residuum Residuum Fill Residuum - - - - -

- - - - - - - - - -Binder Material - - - - - - - - - -

755337.526.519 10013.2 100 93 1009.5 100 100 89 100 1004.75 100 100 82 100 1002 99 98 76 98 990.425 78 75 65 84 840.25 59 59 56 68 520.15 46 50 49 55 400.075 37 44 44 46 340.05 36 42 43 44 340.02 33 37 39 38 250.005 26 24 34 32 200.002 25 17 33 26 9Coarse Sand <2.0 >0.425mm 20.7 23.1 14.3 14.2 15.3 #VALUE! #VALUE! #VALUE! #VALUE! #VALUE!

Soil Fine Sand <0.425>0.05mm 50.8 44.2 49.1 47.7 55.8 #VALUE! #VALUE! #VALUE! #VALUE! #VALUE!Mortar Silt <0.05 >0.005 7.6 14.3 7.0 10.6 11.7 #VALUE! #VALUE! #VALUE! #VALUE! #VALUE!

Clay <0.005 20.9 18.4 29.6 27.5 17.2 #VALUE! #VALUE! #VALUE! #VALUE! #VALUE!Liquid Limit % (m/m) 31.7 33.7 34.8 26.8 25.4 0 0 0 0 0

Atterberg Plasticity Index 0 10.9 7.6 5.4 5.6 0 0 0 0 0Limits Linear Shrinkage % 0 3.3 2.7 2 1.3 0 0 0 0 0

Natural MC % - - - - - - - - - -Mod AASHTO Dry Density kg/m3 1771 1786 1731 1712 1811 0 0 0 0 0Density OMC % 14.7 14.3 17 14.5 12.9 0 0 0 0 0

100% MDD 14 12 7.4 20 14 0 0 0 0 098% 11 11 6.7 18 13 0 0 0 0 0

CBR 95% 6.9 10 5.9 15 12 0 0 0 0 093% (Inferred) * 6 8 5 11 12 #NUM! #NUM! #NUM! #NUM! #NUM!90% 4.7 5 4 7 11 0 0 0 0 0CBR Swell (%) 0.00 0.47 0.18 0.45 0.31 0.00 0.00 0.00 0.00 0.00

AASHTO Soil Classification * A - 4 (0) A - 6 (2) A - 4 (1) A - 4 (0) A - 2 - 4 (0) #VALUE! #VALUE! #VALUE! #VALUE! #VALUE!Grading Modulus 0.85 0.82 1.16 0.71 0.83 #VALUE! #VALUE! #VALUE! #VALUE! #VALUE!TRH 14 (1985) * G10 G9 G10 G8 G8 #VALUE! #VALUE! #VALUE! #VALUE! #VALUE!

Umbumbulu - Ref.32225Laboratory Test Summary

Parti

cle

Siz

e (m

m)

Cum

ulat

ive

% P

assi

ng

Hyd

rom

eter

% P

assi

ng%

Pas

sing

Technical Signatory: ........................... Page 2 of ...

TEST REPORT

Project: Umbumbulu - Ref.32225

Ref no.: 8661 Lab no.: 04079 IP.2Description: Residuum

Depth: 2 - 4.0 -Test Methods: TMH1 METHOD A1(a), A2, A3 & A4, ASTMD422Grading Analysis M.I.T SIZE * PLASTICITYGrain Size (mm)%Passing CLASSIFICATION Liquid Limit, % 31.775 100.0 Cobble% 0.0 Plasticity Index 053 100.0 Gravel% 1.1 Linear Shrinkage, % (L/L) 037.5 100.0 Coarse 0.026.5 100.0 Medium 0.2 GRADING19 100.0 Fine 0.9 D10 Size (mm) <0.00213.2 100.0 Sand% 62.4 Uniformity Coefficient *9.5 100.0 Coarse 18.2 Grading Modulus 0.854.75 99.7 Medium 28.32 98.9 Fine 15.9 CLASSIFICATION *0.425 78.4 Silt% 11.7 Potential Expansiveness Low0.25 59.1 Coarse 3.7 Group Index 00.15 45.7 Medium 6.0 AASHTO Soil Classification A - 40.075 37.5 Fine 2.0 Unified Classification SM0.05 35.9 Clay% 24.80.02 32.80.005 26.40.002 24.8

CBR Swell (%)

Ref no.: 8661 Fig no.: -

Borehole/Pit no.:

MATERIALS ANALYSIS

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%Pa

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Particle Size (mm)

Cobble

GravelSandSiltClay

Fine Med CoarseFine Med CoarseFine Med Coarse

Grading Curve

(mm)

*

* Information marked with an asterisk is outside the scope of Accreditation.The results only relate to the samples tested.The report may not be reproduced except in full. Page 3 of ...

TEST REPORT



Depth: 0 - 4.0 -Test Methods: TMH1 METHOD A1(a), A2, A3 & A4, ASTMD422Grading Analysis M.I.T SIZE * PLASTICITYGrain Size (mm)%Passing CLASSIFICATION Liquid Limit 33.775 100.0 Cobble% 0.0 Plasticity Index 10.953 100.0 Gravel% 2.1 Linear Shrinkage 3.337.5 100.0 Coarse 0.026.5 100.0 Medium 0.3 GRADING19 100.0 Fine 1.8 D10 Size (mm) <0.00213.2 100.0 Sand% 54.7 Uniformity Coefficient NA9.5 99.9 Coarse 20.1 Grading Modulus 0.824.75 99.6 Medium 23.42 97.9 Fine 11.2 CLASSIFICATION *0.425 75.3 Silt% 26.6 Potential Expansiveness Low0.25 59.3 Coarse 6.2 Group Index 20.15 49.6 Medium 12.3 AASHTO Soil Classification A - 60.075 44.3 Fine 8.2 Unified Classification SC0.05 42.5 Clay% 16.60.02 37.00.005 23.90.002 16.6


Borehole/Pit no.:

MATERIALS ANALYSIS

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0.001 0.01 0.1 1 10 100

%Pa

ssin

g

Particle Size (mm)

Cobble

GravelSandSiltClayFine Med CoarseFine Med CoarseFine Med Coarse

Grading Curve

(mm)

*


TEST REPORT



Depth: 0.5 - 2.1 -Test Methods: TMH1 METHOD A1(a), A2, A3 & A4, ASTMD422Grading Analysis M.I.T SIZE * PLASTICITYGrain Size (mm)%Passing CLASSIFICATION Liquid Limit 34.875 100.0 Cobble% 0.0 Plasticity Index 7.653 100.0 Gravel% 24.4 Linear Shrinkage 2.737.5 100.0 Coarse 0.026.5 100.0 Medium 16.5 GRADING19 100.0 Fine 7.9 D10 Size (mm) <0.00213.2 93.2 Sand% 32.4 Uniformity Coefficient NA9.5 88.6 Coarse 9.6 Grading Modulus 1.164.75 81.7 Medium 13.52 75.6 Fine 9.3 CLASSIFICATION *0.425 64.8 Silt% 10.0 Potential Expansiveness Low0.25 56.0 Coarse 4.5 Group Index 10.15 49.1 Medium 3.9 AASHTO Soil Classification A - 40.075 44.0 Fine 1.6 Unified Classification SM0.05 42.7 Clay% 33.20.02 38.70.005 34.50.002 33.2


Borehole/Pit no.:

MATERIALS ANALYSIS

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%Pa

ssin

g

Particle Size (mm)

Cobble


Grading Curve

(mm)

*


TEST REPORT


Ref no.: 8661 Lab no.: 04082 IP.9Description: Fill

Depth: 0.0 - 0.8 -Test Methods: TMH1 METHOD A1(a), A2, A3 & A4, ASTMD422Grading Analysis M.I.T SIZE * PLASTICITYGrain Size (mm)%Passing CLASSIFICATION Liquid Limit 26.875 100.0 Cobble% 0.0 Plasticity Index 5.453 100.0 Gravel% 1.7 Linear Shrinkage 237.5 100.0 Coarse 0.026.5 100.0 Medium 0.3 GRADING19 100.0 Fine 1.4 D10 Size (mm) <0.00213.2 100.0 Sand% 53.1 Uniformity Coefficient NA9.5 100.0 Coarse 12.4 Grading Modulus 0.714.75 99.6 Medium 24.02 98.3 Fine 16.7 CLASSIFICATION *0.425 84.3 Silt% 19.1 Potential Expansiveness Low0.25 68.4 Coarse 6.8 Group Index 00.15 55.3 Medium 5.9 AASHTO Soil Classification A - 40.075 46.4 Fine 6.4 Unified Classification SM - SC0.05 44.4 Clay% 26.10.02 38.40.005 32.00.002 26.1


Borehole/Pit no.:

MATERIALS ANALYSIS

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0.001 0.01 0.1 1 10 100

%Pa

ssin

g

Particle Size (mm)

Cobble


Grading Curve

(mm)

*


TEST REPORT



Depth: 1.8 - 3.8 -Test Methods: TMH1 METHOD A1(a), A2, A3 & A4, ASTMD422Grading Analysis M.I.T SIZE * PLASTICITYGrain Size (mm)%Passing CLASSIFICATION Liquid Limit 25.475 100.0 Cobble% 0.0 Plasticity Index 5.653 100.0 Gravel% 0.9 Linear Shrinkage 1.337.5 100.0 Coarse 0.026.5 100.0 Medium 0.3 GRADING19 100.0 Fine 0.6 D10 Size (mm) 0.002113.2 100.0 Sand% 65.0 Uniformity Coefficient >999.5 99.8 Coarse 13.5 Grading Modulus 0.834.75 99.7 Medium 39.62 99.1 Fine 11.9 CLASSIFICATION *0.425 83.9 Silt% 25.0 Potential Expansiveness Low0.25 52.4 Coarse 9.4 Group Index 00.15 39.6 Medium 4.2 AASHTO Soil Classification A - 2 - 40.075 34.1 Fine 11.4 Unified Classification SM - SC0.05 34.1 Clay% 9.10.02 24.80.005 20.30.002 9.1


Borehole/Pit no.:

MATERIALS ANALYSIS

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10.0

20.0

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0.001 0.01 0.1 1 10 100

%Pa

ssin

g

Particle Size (mm)

Cobble


Grading Curve

(mm)

*


DRAWING № 32225-01 - SITE PLAN

drennan maud (pty) ltd · geotechnical investigation for the proposed umbumbulu shopping centre 1....

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