Ground Investigation Report
44 Queens Walk
Wembley
London
NW9 8ER
Prepared for:
BSK Construction Limited
46 Repton Road
Harrow
HA3 9QD
EPS Reference Number:
UK20.5082
Date Issued:
22nd September 2020
Report Status:
Issue 1
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
44 QUEENS WALK, WEMBLEY
NON-TECHNICAL CLIENT SUMMARY
This report presents the findings of a Ground Investigation undertaken to determine ground conditions
and provide a geotechnical appraisal. Pertinent findings and conclusions may be summarised as follows:





Intrusive investigations involved the drilling of one deep (20 m) borehole to provide ground
conditions information and support geotechnical design for the demolition of the existing building
and construction of seven new flats.
Ground conditions were found to comprise a layer of made ground (fill) to approximately 1m in
depth, directly underlain by clay of the London Clay Formation, which has been found to be a ‘high
volume change potential’ soil.
Spread foundations are considered suitable for use at the site, adopting allowable bearing pressures
ranging from 110kN/m2 at 1.0 to 140kN/m2 at 2.0m below existing ground level. However,
depending on structural loadings, piles may provide a more appropriate foundation solution.
Suspended ground floor construction is also recommended throughout, incorporating a suitable
sub floor void.
A design sulphate class of DS-4 with aggressive concrete (ACEC) of AC-3s (which might require
special protective measures) is recommended for shallow buried concrete in contact with the
underlying natural soils, however it may be possible to mitigate this downwards through the
selection of construction techniques, i.e. method of piling.
The above points represent a simplified summary of the findings of this assessment and should not form
the basis for key decisions for the proposed development. A thorough review of the details is contained
within the following report, or alternatively get in touch and we’ll talk you through it.
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
Project Reference:
UK20.5082
Title:
Ground Investigation Report
44 Queens Walk, Wembley
Client:
BSK Construction Limited
Date:
22nd September 2020
EPS Contact Details:
7B Caxton House
Broad Street
Cambourne
Cambridge CB23 6JN
Status:
Issue 1
Author:
Reviewed:
Authorised:
Daryl Bowell
Steve Bullock
Steve Bullock
Consultant
Director
Director
T: 01954 710666
F: 01954 710677
E: info@epstrategies.co.uk
W: www.epstrategies.co.uk
This report has been prepared for the client(s) listed on the report title page. EPS accepts no liability or responsibility for use of, or reliance
upon, this report and / or the information contained within it by third parties.
If third parties have been contracted / consulted during compilation of this report, the validity of any data they may have supplied, and which
are included in the report, have been assessed as far as possible by EPS however, EPS cannot guarantee the validity of these data.
Where ground investigations have been conducted, these have been limited to the level of detail required for the site in order to achieve the
objectives of the investigation.
No part of this report, or references to it, may be included in published documents of any kind without approval from EPS. This report and
its contents, together with any supporting correspondence or other documentation, remain the property of Environmental Protection
Strategies Ltd until paid for in full.
The report has been written, reviewed and authorised by the persons listed above. It has also undergone EPS’ in house quality management
inspection. Should you require any further assistance regarding the information provided within the report, please do not hesitate to contact
us.
The National Planning Policy Framework requires a competent person to prepare site investigation information, which is defined as a person
with a recognised relevant qualification, sufficient experience in dealing with the type(s) of pollution or land instability, and membership of
a relevant professional organisation. EPS considers that it fulfils these criteria and would welcome any request for staff CVs or case studies to
demonstrate it.
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
TABLE OF CONTENTS
1
1.1
1.2
2
2.1
3
3.1
3.2
3.3
4
4.1
4.1.1
4.1.2
4.2
4.3
4.3.1
4.3.2
5
5.1
5.2
5.2.1
5.2.2
5.3
5.4
5.5
INTRODUCTION .......................................................................................... 1
Scope of Work ........................................................................................1
Limitations and Constraints .........................................................................1
BACKGROUND ............................................................................................. 3
Site Location and Context ..........................................................................3
SUMMARY OF INTRUSIVE INVESTIGATIONS ............................................ 4
Exploratory Hole locations .........................................................................4
Soil Sampling & In-Situ Testing ....................................................................4
Laboratory Testing ...................................................................................4
FINDINGS OF THE INVESTIGATION ............................................................ 5
Ground Conditions ...................................................................................5
Made Ground ...................................................................................................... 5
London Clay Formation ......................................................................................... 5
Groundwater ..........................................................................................5
Geotechnical Testing .................................................................................6
Geotechnical Laboratory Testing ............................................................................... 6
Geotechnical Field Testing ...................................................................................... 6
GEOTECHNICAL APPRAISAL ....................................................................... 8
Geotechnical Category ..............................................................................8
Structural Foundations...............................................................................8
Spread Foundations .............................................................................................. 8
Deep Foundations................................................................................................. 9
Ground Floor Construction ...................................................................... 10
Groundworks........................................................................................ 10
Concrete Grade ..................................................................................... 11
Figures
Figure 1
Figure 2
Site Location Plan
Borehole Location Plan
Tables
Table 1
Laboratory Testing Schedule
Appendices
Appendix A
Appendix B
Appendix C
Appendix D
Selected Site Photographs
Proposed Development Plan
Site Specific Borehole Logs
Laboratory Data
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
1
INTRODUCTION
In August 2020, Environmental Protection Strategies Ltd (EPS) was commissioned by BSK
Construction Limited to complete a Ground Investigation at 44 Queens Walk, Wembley, London,
NW9 8ER (‘the site’). A site location plan is presented as Figure 1 and selected site photographs are
included as Appendix A.
The work was commissioned in order to provide geotechnical information for use in design and
construction of a two and three storey building containing 7 new residential units. A proposed
development plan is included as Appendix B.
1.1 Scope of Work
To perform an exploratory assessment of the site in accordance with the principles and requirements
of BS5930:2015 ‘Code of practice for ground investigations’ and BS EN 1997 ‘Geotechnical Design’, the
following tasks were undertaken:
Intrusive Investigation:





Site walkover/ obtaining photographic records.
Health and safety briefing/ site supervision.
Formation of one deep borehole using a cable percussive drilling rig, to a depth of 20 m below
ground level (bgl).
In-situ testing, to assist geotechnical design.
Logging of ground conditions and collection of representative soil samples for waste
classification and to support geotechnical design.
Reporting:


Data collection and interpretation.
Reporting.
The findings of these investigations and their conclusions are presented in the following sections.
1.2 Limitations and Constraints
The purpose of this report is to present the findings of a soil sampling investigation conducted at the
location(s) specified. When examining the data collected from the investigations made during
the assessment, Environmental Protection Strategies Ltd (EPS) makes the following statements:
No investigation method is capable of completely identifying all ground conditions that might be
present in the soil or groundwater under a site. Where outlined in our report, we have examined
the ground beneath a site by constructing a number of boreholes and / or trial pits to recover soil
and / or groundwater samples. The locations of these excavations and sampling points are
considered to be representative of the condition of the whole site subsurface however, ground
conditions are naturally variable and it may be possible that the ground conditions encountered may
differ to those encountered during the investigation.
1
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
No visible evidence of Japanese Knotweed was identified during the site walkover. However, this
plant can be difficult to identify in the early stages of growth and therefore it is not always possible
to identify its presence at certain times of the year. For this reason, EPS cannot confirm that
Japanese Knotweed rhizomes do not exist and it is recommended that if it is suspected that this
species, or other similarly invasive plants are present at the site, a specialist contractor should be
commissioned to make a detailed assessment.
This report does not include specific investigation for the presence of Potential Asbestos Containing
Material (PACM). Specialist contractors should be commissioned to make detailed assessments and
recommendations if these materials are suspected.
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Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
2
BACKGROUND
2.1 Site Location and Context
Detail
Location
National Grid
Reference
Topography
Description of
Site
Description
The site is located approximately 1.5 km northeast of Wembley Park,
adjacent to the junction between Queens Walk and the A4140.
520188, 186904
Gently sloping from 48m Above Ordnance Datum (AOD) along the
southern perimeter of site, to approximately 47 m AOD in the north.
Intrusive works were undertaken on the 17th and 18th August 2020, and it
was found that the site is roughly square shaped, covering an area of
approximately 600m2.
The site is bordered on all sides by wooden panel fencing, with access to the
site through a secure metal gate on Queens Road. The existing two-storey
property is located on the centre of the site, with an attached single storey
garage building bordering the neighbouring property to the east. Both
buildings appeared abandoned with the rest of the site covered by overgrown
grass and weeds, with the exception of a small driveway leading from the
entrance to the old garage building. Two mature trees are located to the
west, just inside of the wooden fencing that demarcates the site boundary,
both in excess of 5m in height.
Notably a large pile of soil/vegetation and construction debris (including
piping, doors, wood panelling) was present near to the entrance of the site,
however this was removed on the 17th August to facilitate access for the
works. Similar piles of soil and debris were observed behind the building in
the rear garden area.
Ground
Conditions
British Geological Survey (BGS) records suggest the site is underlain by
bedrock geology comprising of clays, silts and sands of the London Clay
Formation.
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Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
3
SUMMARY OF INTRUSIVE INVESTIGATIONS
The intrusive ground investigation was undertaken over the 17th & 18th August 2020 in accordance
with EPS standard operating procedures, copies of which will be made available on request. A
summary of the site activities is presented in the following sections:
3.1 Exploratory Hole locations
The location of the intrusive position was selected through consideration of the proposed layout of
the scheme, consultation with the client, below ground utilities information, access constraints as
well as operational and health and safety considerations.
The overall objective for the ground investigation works was to provide a more detailed assessment
of the ground conditions at depth beneath the site to inform foundation design.
The borehole was formed in accordance with standard EPS drilling methodologies and
subcontractors were supervised at all times by an EPS engineer.
A detailed plan showing the location of the intrusive position is presented as Figure 2.
3.2 Soil Sampling & In-Situ Testing
The borehole was logged for ground conditions encountered and representative soil samples were
obtained throughout.
Alternating standard penetration tests (SPTs) and undisturbed samples were obtained at
approximately 1m intervals within the deep cable percussive borehole (BH01). For the SPT test,
the number of blows required to advance a standard split spoon, over the final 300 mm of a 450 mm
total drive was recorded and is shown on the borehole record at the penetration resistance (“N”
value).
3.3 Laboratory Testing
Samples obtained for pH and Sulphate analysis were submitted Element Materials Technology of
Flintshire, who hold appropriate UKAS / MCERT accreditation for the required testing. Samples
were transported in laboratory supplied containers and delivered by an approved courier.
The geotechnical testing was undertaken by Soil Property Testing, Huntingdon, a UKAS accredited
laboratory. Copies of chain of custody documentation are held by EPS and will be made available
on request.
A laboratory testing schedule is included as Table 1.
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44 Queens Walk, Wembley
EPS Ref: UK20.5082
4
FINDINGS OF THE INVESTIGATION
This section of the report provides a summary of the findings of the intrusive investigations
completed by EPS in August 2020.
4.1 Ground Conditions
The ground conditions encountered, from surface level, were interpreted to comprise:


Made Ground
London Clay Formation
A site-specific borehole log is included as Appendix C and gives descriptions and depths of strata
encountered. A summary of the general strata encountered across the site is provided in the table
below, with more detailed description given in the following sub-sections.
4.1.1
Geological Strata
Maximum Depth to Base
of Strata (m bgl)
Strata Thickness (m)
Made Ground
1
1
London Clay Formation
>20
>19 (not proven)
Made Ground
A surface layer of made ground was encountered to a depth of 1 m and this was found to consist of
brown gravelly clay, with gravel consisting predominantly of coarse brick fragments.
4.1.2
London Clay Formation
Soils interpreted as the London Clay Formation were encountered beneath the made ground from
a depth of 1 m, initially present as a brown clay before transitioning to blue clay from 11.9 m below
ground level.
4.2 Groundwater
Groundwater was not encountered during the intrusive activities.
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44 Queens Walk, Wembley
EPS Ref: UK20.5082
4.3 Geotechnical Testing
4.3.1
Geotechnical Laboratory Testing
The results of geotechnical laboratory testing are summarised in the table below.
Strata
London Clay
Formation
Moisture
Content (%)
Min
Max
26.9
28.8
Range of Parameters
Plasticity Index Undrained Shear
(%)
Strength (kPa)
Min
Max
Min
Max
46
54
143
251
Moisture Content and Atterberg Limit tests were undertaken on four samples of cohesive soils in
accordance with BS EN ISO: 17892-1: 2014 & BS1377: Part 2: 3.2, 4.4, 5.3, 5.4.
Triaxial tests (single-stage) were completed for three samples of cohesive soil in accordance with
BS1377: Part 1: 1990 and BS1377: Part 7: 1990: 8 & 9.
A laboratory analysis testing schedule is presented as Table 1 and all geotechnical sample results
obtained from the laboratory are also included as Appendix D. Sulphate contents and pH values
determinations were carried out by the analytical laboratory, the results of which are included in
Appendix D and summarised in section 5.6 (below).
4.3.2
Geotechnical Field Testing
The results of the in-situ SPT testing undertaken throughout the formation of BH01 are presented
in the graph below.
From the data, there is a strong correlation evident between the strength of the soils and depth, with
all ‘N’ values within the clay bedrock steadily increasing from 28 at 5 m depth, to 46 from 19.5 m
below ground level.
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44 Queens Walk, Wembley
EPS Ref: UK20.5082
N Value
0
10
20
30
40
50
0
-2
-4
-6
Depth (m bgl)
-8
-10
-12
-14
-16
-18
-20
7
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
5
GEOTECHNICAL APPRAISAL
The findings of this intrusive assessment have indicated ground conditions across the site to comprise
a surface layer of made ground overlying clay bedrock of the London Clay Formation, proven to at
least 20m.
5.1 Geotechnical Category
Geotechnical
Category
(BS EN 19971:2004)
GC1
GC2
GC3
Definition
Geotechnical Category 1 (GC1) should only include small and relatively
simple structures for which it is possible to ensure that the fundamental
requirements will be satisfied on the basis of experience and qualitative
geotechnical investigations with negligible risk in terms of overall stability or
ground movements and in ground conditions which are known.
Geotechnical Category 2 (GC2) should include conventional types of
structure and foundation with no exceptional risk or difficult loading
conditions. Designs for structures in Geotechnical Category 2 should
normally include quantitative geotechnical data and analysis.
Geotechnical Category 3 (GC3) should include structures or parts of
structures, which fall outside the limits of Geotechnical Categories 1 and 2.
This may include very large/unusual structures, structures involving
abnormal risks, or unusual or exceptionally difficult ground or loading
conditions, or structures in areas of probable site instability or persistent
ground movements that require separate investigation.
The proposed scheme is anticipated to comprise the demolition of the existing two storey building
and the construction of seven new residential flats. Therefore, the below assessment has been
undertaken in accordance with Geotechnical Category 2 (GC2), including conventional types of
structure and foundation with no exceptional risk or difficult ground or loading conditions, as
defined by BS EN 1997-1:2004.
5.2 Structural Foundations
5.2.1
Spread Foundations
As detailed above, the development includes the construction of new residential dwellings, with
foundations being vertically loaded. The foundation assessment has therefore been undertaken in
accordance with BS EN 1997-1:2004, to take into account:


Bearing Pressure (Ultimate Limit State)
Settlement (Serviceability Limit State)
The ground conditions are considered suitable for the use of conventional spread foundations, either
strip footings or pad foundations bearing on the underlying London Clay Formation.
A minimum foundation depth of 1.0m, below existing or proposed ground level is considered
suitable for the site, subject to the following provisos:8
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
a) Foundations should fully penetrate any made ground and should extend a minimum of 150mm
in to undisturbed natural strata. It should be noted that Made Ground extended to a depth of at
1.0m in BH01 and it is possible that therefore average foundation depths are likely to exceed
the advised minimum.
b) The London Clay should be considered as having a high-volume change potential and therefore,
where affected by trees, foundations must be designed in full accordance within Chapter 4.2 of
NHBC Standard “Building Near Trees”.
Full anti-heave precautions will be required where foundation depths exceed 1.50m due to the
influence of trees.
Allowable bearing capacities for the Clay are provided in the table below. The allowable bearing
capacity is the permissible increase in vertical stress at the level of the underside of the foundation,
above existing overburden pressure, which may be calculated on the basis of a soil density of
19kN/m3.
Depth (m bgl)
1.0
1.5
2.0
Allowable Bearing
Capacity (kN/m2)
110
125
140
*BS EN 1997 (EC7) Geo Load Combination 2
At the above bearing pressure, total settlements are unlikely to exceed approximately 20mm to
25mm. Settlements in clay will comprise both immediate and long term (consolidation) settlement
and will take place over a long period of time.
5.2.2
Deep Foundations
Should structural loads exceed the above allowable bearing pressures the use of deep foundation
solutions such as piles could also be considered.
The ground conditions are considered suitable for the use of bored or driven piles. However, the
use of driven piles may cause noise and vibration nuisance to site neighbours and adjacent structures
which would possibly negate their use.
Piles are considered likely to terminate in the underlying London Clay Formation and carry their
loads in a combination of end bearing and skin friction. It would be unwise to assume any positive
contribution to skin friction within any made or disturbed ground. Piles will need to be designed
in full accordance with NHBC Standards and should incorporate reinforcement and anti-heave
precautions where necessary.
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44 Queens Walk, Wembley
EPS Ref: UK20.5082
A preliminary assessment of potential pile capacities, for a single isolated continuous flight auger
(CFA) has been provided in the table below, although in view of the wide variety of piles sizes
available, and the range of installation plant and techniques, the design of the piles should be carried
out by, and should remain the responsibility of the specialist piling contractor, who will reflect their
own methods, experience and design procedures within their proposals
Approximate Allowable Working Load (kN)
Depth of pile below
ground level (m bgl)
300mm
Diameter Pile
450mm Diameter
Pile
600mm Diameter
Pile
10
205
330
470
12
270
438
620
15
390
620
870
Note: A Factor of Safety of 2.5 has been adopted
5.3 Ground Floor Construction
Given the likely use of piling at the site as well as the cohesive, near surface soils being susceptible
to volume change, suspended ground floor slabs are recommended, incorporating a sub-floor void
sufficient for a high volume change potential soil.
5.4 Groundworks
Whilst excavations in the cohesive soils may remain stable for short periods during construction,
the long-term suitability of these and any excavations in made or disturbed ground should not be
relied upon in unsupported excavations.
Heavy plant and stockpiles of materials should not be permitted close to the edges of unsupported
excavations. Further reference should be made to CIRIA Report No. 97 ‘Trenching Practice’ 1992.
On the basis of the findings of the ground investigation, significant quantities of groundwater are
unlikely to be encountered within shallow excavations for foundations.
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44 Queens Walk, Wembley
EPS Ref: UK20.5082
5.5 Concrete Grade
Sulphate contents and pH values determinations were carried out by the environmental laboratory,
the results of which are also included within Appendix D. Results for concrete grade testing are
summarised within the following table:
Strata
London Clay
Formation
Water soluble
Sulphate
(mg/l SO4)
Min
Max
Min
Max
Min
Max
562.9
7.72
8.34
0.51
2.28
2,857.8
Total Potential
Sulphate (%)
pH
In accordance with Part 1 of the BRE Special Digest 1 ‘Concrete in Aggressive Ground’ 2005 for datasets
with between five to nine samples the mean of the highest two values have been used. Total Sulphur
and consequently Total Potential Sulphate values have been used to determine a design sulphate class
of DS-4 with an aggressive chemical environment for concrete (ACEC) of AC-3s for the natural
London Clay Formation, which is a high concrete grade and may need special protective measures.
It should be noted that this classification has been driven by the Total Potential Sulphate value,
however, the values for pH and the Water-Soluble Sulphate give a lower class of DS-3 with ACEC
of AC-2s.
If piles were to be used at the site it should be noted that the BRE Special Digest 1 ‘Concrete in
Aggressive Ground’ 2005 states “Concrete in pyritic ground which is initially low in soluble sulphate does
not have to be designed to withstand a high potential sulphate class unless it is exposed to ground which has been
disturbed to the extent that contained pyrite might oxidise and the resultant sulphate ions reach the concrete.
This may prompt redesign of the structure or construction process to avoid ground disturbance; for example, by
using precast or cast in-situ piles instead of constructing a spread footing within an excavation”.
11
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
FIGURES
Crown Copyright. All rights reserved.
Licence Number: 100054115
Approximate Site Location
Title:
Site Location Plan
Scale:
NTS
Project: 44 Queens Walk, Wembley,
London, NW9 8ER
Fig No: 1
Drawn By: DB
Approved By: WE
UK20.5082
Job No:
Dwg No:
QueensWalk/0920/01
Date:
September 2020
KEY:
Approximate Site Boundary
Approximate Borehole Location
BH01
Fig No: 2
Title:
Borehole Location Plan
Project: 44 Queens Walk Wembley
Scale:
Drawn By:
Job No:
Dwg No:
Date:
NTS - For Illustration purposes only
DB
UK20.5082
QueensWalk/0920/02
September 2020
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
TABLES
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
Table 1 – Laboratory Testing Schedule
Sample
ID
BH01
Notes:
mbgl
1
-
Moisture
Sample Depth Content/
(m bgl)
Plastic
Limits
2-2.45
4-4.45
1
7.5-7.95
1
13.5-13.95
1
18.45-19.45
1
3-3.45
5-5.45
9-9.45
12-12.45
16.5-16.95
19.5-19.95
-
meters below ground level
Sample Taken
Sample Not Analysed
Triaxial
Traditionals
Test
1
1
1
-
1
1
1
1
1
1
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
APPENDICES
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
APPENDIX A
Selected Site Photographs
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
Photo 1: Photo of site access from Queens Walk.
Photo 2: View of garden area to west of existing building.
Photo 3: Garden area to the rear of the building.
Photo 4: Photograph of driveway and attached garage
building.
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
APPENDIX B
Proposed Development Plan
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
APPENDIX C
Site Specific Borehole Logs
Borehole No.
Borehole Log
Project No.
UK20.5082
Project Name:
Queens Walk, Wembley
Location:
44 Queens Walk, Wembley, London, NW9 8ER
Level:
Client:
BSK Construction
Dates:
Well
Water
Strikes
Sample and In Situ Testing
Depth (m) Type
In Situ Results
0.00 - 1.00
0.00 - 1.00
B
ES
1.00 - 1.20
D
1.20 - 1.65
1.20
D
SPT
2.00 - 2.45
U
3.00 - 3.45
3.00
D
SPT
4.00 - 4.45
U
5.00 - 5.45
5.00
D
SPT
N=28 (7,7/7,7,7,7)
6.00 - 6.45
6.00
D
SPT
N=27 (7,7/7,6,7,7)
Depth
(m)
Level
(m)
Co-ords:
Legend
17/08/2020
BH01
Sheet 1 of 2
Hole Type
CP
Scale
1:51
Logged By
Stratum Description
MADE GROUND: Brown CLAY with frequent brick fragments.
1.00
Firm becoming stiff brown CLAY (LC)
1
N=8 (2,3/2,2,2,2)
2
N=18 (2,3/3,5,5,5)
3
4
5
6
7
7.50 - 7.95
7.50
D
SPT
N=27 (7,6/6,7,7,7)
8
9.00 - 9.45
9.00
D
SPT
N=28 (7,7/7,7,7,7)
9
10
Remarks
LC= London Clay Formation
Groundwater was not encountered during drilling.
Borehole No.
Borehole Log
Project No.
UK20.5082
Project Name:
Queens Walk, Wembley
Location:
44 Queens Walk, Wembley, London, NW9 8ER
Level:
Client:
BSK Construction
Dates:
Well
Water
Strikes
Sample and In Situ Testing
Depth (m) Type
In Situ Results
Depth
(m)
Level
(m)
Co-ords:
Legend
17/08/2020
BH01
Sheet 2 of 2
Hole Type
CP
Scale
1:51
Logged By
Stratum Description
Firm becoming stiff brown CLAY (LC)
10.50 10.95
10.50
10.95
12.00 12.45
12.00
D
SPT
B
N=31 (8,7/8,8,8,7)
11
11.90
D
SPT
Stiff bluish grey CLAY (LC))
12
N=36 (9,9/9,9,9,9)
13
13.50 13.95
U
14
15.00 15.45
15.00
D
SPT
15
N=44
(10,10/11,11,11,11)
16
16.50 16.95
16.50
18.00 18.45
18.00
18.45 19.45
D
SPT
N=45
(11,10/11,12,11,11)
17
D
SPT
18
N=44
(10,10/11,11,11,11)
B
19
19.50 19.95
19.50
D
SPT
N=46
(11,12/12,11,11,12)
Remarks
LC= London Clay Formation
Groundwater was not encountered during drilling.
20.00
End of Borehole at 20.000m
20
Ground Investigation Report
44 Queens Walk, Wembley
EPS Ref: UK20.5082
APPENDIX D
Laboratory Data
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099801
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
Client:
Environmental Protection Strategies
Ltd
Soil Property Testing Ltd
15, 16, 18 Halcyon Court, St Margaret's Way,
Stukeley Meadows, Huntingdon,
Cambridgeshire, PE29 6DG
Unit 7
Caxton House
Broad Street
Great Cambourne
Cambridge
CB23 6JN
Samples Submitted By:
Environmental Protection Strategies
Ltd
Tel: 01480 455579
Email: enquiries@soilpropertytesting.com
Website: www.soilpropertytesting.com
Approved Signatories:
J.C. Garner B.Eng (Hons) FGS
Technical Director & Quality Manager
S.P. Townend
Samples Labelled:
UK20.5082 - Queens Walk, Wembley
Chairman
W. Johnstone
Materials Lab Manager
D. Sabnis
Operations Manager
Date Received:
25/08/2020
Samples Tested Between:
25/08/2020 and 07/09/2020
Remarks:
For the attention of Daryl Bowell
Your Reference No: UK20.5082
Your Order No: 24869
Notes:
1
All remaining samples or remnants from this contract will be disposed of after 21 days from today,
unless we are notified to the contrary.
2
(a)
(b)
3
Tests marked "NOT UKAS ACCREDITED" in this test report are not included in the UKAS Accreditation
Schedule for this testing laboratory.
4
This test report may not be reproduced other than in full except with the prior written approval of the
issuing laboratory.
UKAS - United Kingdom Accreditation Service.
Opinions and interpretations expressed herein are outside the scope of UKAS accreditation.
Page 1 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
Scheduled By
Environmental Protection Strategies Ltd
Target Date
07/09/2020
SCHEDULE OF LABORATORY TESTS
Bore
Hole
No.
Type
Sample
Ref.
Top
Depth
Tr
iax
W ial T
at es
e
t
Liq r Co
ui nt
d/ en
Pl t
as (B
tic SE
Lim N)
its
Schedule Remarks
BH01
U
1
2.00
1
BH01
U
2
4.00
1
BH01
D
7
7.50
BH01
U
3
13.50
BH01
B
3
18.45
Totals
1
3
1
1
1
1
1
1
1
1
4
4
Sample Remarks
End of Schedule
Page 2 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
SUMMARY OF WATER CONTENT, LIQUID LIMIT, PLASTIC LIMIT, PLASTICITY INDEX AND LIQUIDITY INDEX
Borehole
/Pit No.
Depth
Type
Ref.
(m)
Liquidity
Index
(%)
Plasticity
Index
(%)
Water
Content
Liquid
Limit
Plastic
Limit
(%)
(%)
Sample Preparation
Method
Ret'd
0.425mm
Corr'd
W/C
Curing
Time
(%)
<0.425mm
(hrs)
Description
Class
BH01
4.00 - 4.45
U
2
28.8
77
26
51
0.05
From
Natural
0 (A)
26
Stiff (high strength) dark yellowish brown
CLAY with rare bluish grey mottling, and
selenite crystals.
CV
BH01
7.50 - 7.95
D
7
28.5
75
27
48
0.03
From
Natural
0 (A)
25
Stiff dark yellowish brown CLAY with rare
selenite crystals.
CV
BH01
13.50 13.95
U
3
26.9
72
26
46
0.02
From
Natural
0 (A)
24
Very stiff (very high strength) fissured dark
yellowish brown CLAY.
CV
BH01
18.45 19.45
B
3
28.2
81
27
54
0.02
From
Natural
0 (A)
25
Very stiff dark greyish brown CLAY with rare
dark grey mottling.
CV
Method Of Preparation:
Method of Test:
Type of Sample Key:
Comments:
BS EN ISO: 17892-1: 2014 & BS 1377: Part 2:1990:4.2
BS EN ISO: 17892-1: 2014 & BS 1377: Part 2:1990:3.2, 4.4, 5.3, 5.4
U = Undisturbed, B = Bulk, D = Disturbed, J = Jar, W = Water, SPT = Split Spoon Sample, C = Core Cutter
Table Notation:
Ret'd 0.425mm: (A) = Assumed, (M) = Measured
www.soilpropertytesting.com
Page 3 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No. 37387_1
PLOT OF PLASTICITY INDEX AGAINST LIQUID LIMIT USING
CASAGRANDE CLASSIFICATION CHART
Low
Medium
Plasticity
High
Very High
Extremely High
80
CL
CI
CH
CV
CE
ML
MI
MH
MV
ME
50
40
Medium
Plasticity Index (Ip)
60
30
Low
20
NHBC Volume Change Potential
High
70
10
0
0
10
20
30
40
50
60
70
80
90
100
110
120
130
Liquid Limit (%)
Plasticity Chart BS5930: 2015: Figure 8
Method of Preparation:
BS 1377: Part 2: 1990: 4.2
Method of Test:
BS1377: Part 2: 3.2, 4.4, 5.3, 5.4
Type of Sample Key:
U = Undisturbed, B = Bulk, D = Disturbed, J = Jar, W = Water, SPT = Split Spoon Sample, C = Core Cutter
Comments:
Volume Change Potential: NHBC Standards Chapter 4.2 Unmodified Plasticity Index
www.soilpropertytesting.com
Page 4 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF WATER CONTENT, LIQUID LIMIT AND PLASTIC LIMIT AND
DERIVATION OF PLASTICITY INDEX AND LIQUIDITY INDEX
Borehole
Water
Depth
Sample
/ Pit No.
Content
m Type Reference (W) %
BH01
4.00 4.45
U
2
28.8
Description
Stiff (high strength) dark yellowish brown CLAY with rare bluish grey
mottling, and selenite crystals.
PREPARATION
Method of preparation
Sample retained 0.425mm sieve
77 %
From natural Plastic Limit
26 %
0%
Corrected water content for material passing 0.425mm
Curing time
Plasticity Index
51 %
Liquidity Index
(Assumed)
26 hrs
Specimen dried at 80°C due to the
presence of selenite.
Liquid Limit
(Assumed)
Sample retained 2mm sieve
Remarks
0%
Clay Content
0.05
NHBC Modified (I'p)
n/a
Derived Activity
Not analysed
Not analysed
C=CLAY
CL
CI
CH
CV
CE
ML
MI
MH
MV
ME
High
60
50
(Ip)
Medium
Plasticity Index
40
%
30
Low
20
NHBC Volume Change Potential
70
10
M=SILT
0
0
10
20
30
40
50
60
70
80
90
100
110
120
Liquid Limit %
Plasticity Chart BS5930: 2015: Figure 8
Method of Preparation: BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 4.2
BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 3.2, 4.4, 5.3, 5.4
Method of Test:
U=Undisturbed,
B=Bulk, D=Disturbed, J=Jar, W=Water, SPT=Split Spoon Sample, C=Core Cutter
Type of Sample Key:
Comments:
www.soilpropertytesting.com
Page 5 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF WATER CONTENT, LIQUID LIMIT AND PLASTIC LIMIT AND
DERIVATION OF PLASTICITY INDEX AND LIQUIDITY INDEX
Borehole
Water
Depth
Sample
/ Pit No.
Content
m Type Reference (W) %
BH01
7.50 7.95
D
7
28.5
Description
Method of preparation
Liquid Limit
75 %
From natural Plastic Limit
27 %
(Assumed)
0%
Corrected water content for material passing 0.425mm
Sample retained 2mm sieve
Curing time
Plasticity Index
48 %
Liquidity Index
(Assumed)
25 hrs
Specimen dried at 80°C due to the
presence of selenite.
Stiff dark yellowish brown CLAY with rare selenite crystals.
PREPARATION
Sample retained 0.425mm sieve
Remarks
0%
Clay Content
0.03
NHBC Modified (I'p)
n/a
Derived Activity
Not analysed
Not analysed
C=CLAY
CL
CI
CH
CV
CE
ML
MI
MH
MV
ME
High
60
50
(Ip)
Medium
Plasticity Index
40
%
30
Low
20
NHBC Volume Change Potential
70
10
M=SILT
0
0
10
20
30
40
50
60
70
80
90
100
110
120
Liquid Limit %
Plasticity Chart BS5930: 2015: Figure 8
Method of Preparation: BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 4.2
BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 3.2, 4.4, 5.3, 5.4
Method of Test:
U=Undisturbed,
B=Bulk, D=Disturbed, J=Jar, W=Water, SPT=Split Spoon Sample, C=Core Cutter
Type of Sample Key:
Comments:
www.soilpropertytesting.com
Page 6 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF WATER CONTENT, LIQUID LIMIT AND PLASTIC LIMIT AND
DERIVATION OF PLASTICITY INDEX AND LIQUIDITY INDEX
Borehole
Water
Depth
Sample
/ Pit No.
Content
m Type Reference (W) %
BH01
13.50 U
13.95
3
26.9
Description
Method of preparation
Liquid Limit
72 %
From natural Plastic Limit
26 %
(Assumed)
0%
Corrected water content for material passing 0.425mm
Sample retained 2mm sieve
Curing time
Plasticity Index
46 %
Liquidity Index
(Assumed)
24 hrs
Specimen dried at 80°C due to the
presence of selenite.
Very stiff (very high strength) fissured dark yellowish brown CLAY.
PREPARATION
Sample retained 0.425mm sieve
Remarks
0%
Clay Content
0.02
NHBC Modified (I'p)
n/a
Derived Activity
Not analysed
Not analysed
C=CLAY
CL
CI
CH
CV
CE
ML
MI
MH
MV
ME
High
60
50
(Ip)
Medium
Plasticity Index
40
%
30
Low
20
NHBC Volume Change Potential
70
10
M=SILT
0
0
10
20
30
40
50
60
70
80
90
100
110
120
Liquid Limit %
Plasticity Chart BS5930: 2015: Figure 8
Method of Preparation: BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 4.2
BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 3.2, 4.4, 5.3, 5.4
Method of Test:
U=Undisturbed,
B=Bulk, D=Disturbed, J=Jar, W=Water, SPT=Split Spoon Sample, C=Core Cutter
Type of Sample Key:
Comments:
www.soilpropertytesting.com
Page 7 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF WATER CONTENT, LIQUID LIMIT AND PLASTIC LIMIT AND
DERIVATION OF PLASTICITY INDEX AND LIQUIDITY INDEX
Borehole
Water
Depth
Sample
/ Pit No.
Content
m Type Reference (W) %
BH01
18.45 B
19.45
3
28.2
Description
Very stiff dark greyish brown CLAY with rare dark grey mottling.
PREPARATION
Method of preparation
Sample retained 0.425mm sieve
Liquid Limit
81 %
From natural Plastic Limit
27 %
(Assumed)
0%
Corrected water content for material passing 0.425mm
Sample retained 2mm sieve
Curing time
Plasticity Index
54 %
Liquidity Index
(Assumed)
25 hrs
Remarks
0%
Clay Content
0.02
NHBC Modified (I'p)
n/a
Derived Activity
Not analysed
Not analysed
C=CLAY
CL
CI
CH
CV
CE
ML
MI
MH
MV
ME
High
60
50
(Ip)
Medium
Plasticity Index
40
%
30
Low
20
NHBC Volume Change Potential
70
10
M=SILT
0
0
10
20
30
40
50
60
70
80
90
100
110
120
Liquid Limit %
Plasticity Chart BS5930: 2015: Figure 8
Method of Preparation: BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 4.2
BS EN ISO: 17892-1: 2014 & BS 1377: Part 2: 1990: 3.2, 4.4, 5.3, 5.4
Method of Test:
U=Undisturbed,
B=Bulk, D=Disturbed, J=Jar, W=Water, SPT=Split Spoon Sample, C=Core Cutter
Type of Sample Key:
Comments:
www.soilpropertytesting.com
Page 8 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF DENSITY, WATER CONTENT AND UNDRAINED SHEAR STRENGTH IN TRIAXIAL
COMPRESSION WITHOUT MEASURMENT OF PORE PRESSURE
Borehole
/Pit No.
Depth
Type
Reference
(m)
Water
Content
Bulk
Density
Dry
Density
Lateral
Pressure
Deviator
Stress
Shear
Stress
(%)
(Mg/m³)
(Mg/m³)
(kPa)
(kPa)
(kPa)
Mohrs Circle
Analysis
Cu (kPa)
Description
Ø degrees
BH01
2.08
U
1
23.1
2.05
1.67
40
502
251
Very stiff (very high strength) dark
yellowish brown CLAY with occasional
selenite crystals, and rare decayed
roots.
BH01
4.04
U
2
28.8
1.96
1.52
82
285
143
Stiff (high strength) dark yellowish
brown CLAY with rare bluish grey
mottling, and selenite crystals.
BH01
13.53
U
3
26.9
1.96
1.54
271
313
157
Very stiff (very high strength) fissured
dark yellowish brown CLAY.
Method of Preparation:
Method of Test:
Type of Sample Key:
Comments:
Remarks to Include:
BS 1377: Part 1: 1990: 7.4.2 & 8, Part 2: 1990: 7.2, Part 7: 1990: 8.3
BS 1377: Part 2: 1990:3 Determination of Moisture Content, Part2: 1990:7 Determination of Density, Part 7: 1990: 8 Undrained Shear
Strenth, 9 Multistage Loading
U = Undisturbed, B = Bulk, D = Disturbed, J = Jar, W = Water, SPT = Split Spoon Sample, C = Core Cutter
Sample disturbance, loss of moisture, variation from test procedure, location and origin of test specimen within original sample, oven
drying temperature if not 105-110°C
www.soilpropertytesting.com
Page 9 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF UNDRAINED SHEAR STRENGTH IN TRIAXIAL COMPRESSION WITHOUT MEASUREMENT
OF PORE PRESSURE
Borehole
Depth (m)
/Pit No.
Type
2.00 2.45
BH01
Reference
U
Initial Specimen
Depth of
Top of
Specimen
(m)
Description
Remarks
Premature failure at 8.5% strain. Short
sample recovery - U38 specimen tested.
Specimen oven dried at 80°C due to the
presence of selenite.
Very stiff (very high strength) dark yellowish brown CLAY with
occasional selenite crystals, and rare decayed roots.
1
Height
Diameter
Weight
Water Content
Bulk Density
Dry Density
(mm)
(mm)
(g)
(%)
(Mg/m³)
(Mg/m³)
76.4
37.6
174
23.1
2.05
1.67
2.08
TEST INFORMATION
Rate of Strain
2.1
% per Min
Rubber Membrane Thickness
0.3
mm
Measured Deviator Stress (kPa)
600
500
400
300
200
100
0
0
2
4
6
8
10
12
14
16
18
20
Strain (%)
Specimen at failure
Method of Preparation:
Method of Test:
Type of Sample Key:
Comments:
Remarks to Include:
Stress Corrections (kPa)
Measured Cell
Pressure, σ3
(kPa)
Strain at Failure
(%)
40
8.5
Rubber
Membrane
Piston Friction
1.6
\
Corrected Max. Shear Stress Cu,
Deviator Stress,
½(σ1-σ3)f
(σ1-σ3)f (kPa)
(kPa)
502
Mohrs Circle Analysis
Cu
(kPa)
PHI
(degrees)
251
BS 1377: Part 1: 1990
BS 1377: Part 7: 1990: 8 Definitive Method, 1990: 9 Multi-stage loading
U = Undisturbed, B = Bulk, D = Disturbed, J = Jar, W = Water, SPT = Split Spoon Sample, C = Core Cutter
Tested in Vertical Condition
UKAS Calibration - loads from 0.2 to 10kN
Sample disturbance, loss of moisture, variation form test procedure, location and origin of test specimen within original sample, oven drying
temperature if not 105-110°C
www.soilpropertytesting.com
Page 10 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF UNDRAINED SHEAR STRENGTH IN TRIAXIAL COMPRESSION WITHOUT MEASUREMENT
OF PORE PRESSURE
Borehole
Depth (m)
/Pit No.
Type
Reference
U
2
4.00 4.45
BH01
Initial Specimen
Depth of
Top of
Specimen
(m)
Description
Remarks
Stiff (high strength) dark yellowish brown CLAY with rare bluish grey
mottling, and selenite crystals.
Specimen oven dried at 80°C due to the
presence of selenite.
Height
Diameter
Weight
Water Content
Bulk Density
Dry Density
(mm)
(mm)
(g)
(%)
(Mg/m³)
(Mg/m³)
169.7
101.3
2684
28.8
1.96
1.52
4.04
TEST INFORMATION
Rate of Strain
1.0
% per Min
Rubber Membrane Thickness
0.3
mm
Measured Deviator Stress (kPa)
350
300
250
200
150
100
50
0
0
2
4
6
8
10
12
14
16
18
20
Strain (%)
Specimen at failure
Method of Preparation:
Method of Test:
Type of Sample Key:
Comments:
Remarks to Include:
Stress Corrections (kPa)
Measured Cell
Pressure, σ3
(kPa)
Strain at Failure
(%)
82
8.5
Rubber
Membrane
Piston Friction
0.6
\
Corrected Max. Shear Stress Cu,
Deviator Stress,
½(σ1-σ3)f
(σ1-σ3)f (kPa)
(kPa)
285
Mohrs Circle Analysis
Cu
(kPa)
PHI
(degrees)
143
BS 1377: Part 1: 1990
BS 1377: Part 7: 1990: 8 Definitive Method, 1990: 9 Multi-stage loading
U = Undisturbed, B = Bulk, D = Disturbed, J = Jar, W = Water, SPT = Split Spoon Sample, C = Core Cutter
Tested in Vertical Condition
UKAS Calibration - loads from 0.2 to 10kN
Sample disturbance, loss of moisture, variation form test procedure, location and origin of test specimen within original sample, oven drying
temperature if not 105-110°C
www.soilpropertytesting.com
Page 11 of 12
TEST REPORT
ISSUED BY SOIL PROPERTY TESTING LTD
DATE ISSUED: 07/09/2020
099800
Contract
UK20.5082 - Queens Walk, Wembley
Serial No.
37387_1
DETERMINATION OF UNDRAINED SHEAR STRENGTH IN TRIAXIAL COMPRESSION WITHOUT MEASUREMENT
OF PORE PRESSURE
Borehole
Depth (m)
/Pit No.
Type
Reference
U
3
13.50 13.95
BH01
Initial Specimen
Depth of
Top of
Specimen
(m)
Description
Remarks
Specimen oven dried at 80°C due to the
presence of selenite.
Very stiff (very high strength) fissured dark yellowish brown CLAY.
Height
Diameter
Weight
Water Content
Bulk Density
Dry Density
(mm)
(mm)
(g)
(%)
(Mg/m³)
(Mg/m³)
170.2
102.0
2728
26.9
1.96
1.54
13.53
TEST INFORMATION
Rate of Strain
1.0
% per Min
Rubber Membrane Thickness
0.3
mm
Measured Deviator Stress (kPa)
350
300
250
200
150
100
50
0
0
2
4
6
8
10
12
14
16
18
20
Strain (%)
Specimen at failure
Method of Preparation:
Method of Test:
Type of Sample Key:
Comments:
Remarks to Include:
Stress Corrections (kPa)
Measured Cell
Pressure, σ3
(kPa)
Strain at Failure
(%)
271
11.5
Rubber
Membrane
Piston Friction
0.7
\
Corrected Max. Shear Stress Cu,
Deviator Stress,
½(σ1-σ3)f
(σ1-σ3)f (kPa)
(kPa)
313
Mohrs Circle Analysis
Cu
(kPa)
PHI
(degrees)
157
BS 1377: Part 1: 1990
BS 1377: Part 7: 1990: 8 Definitive Method, 1990: 9 Multi-stage loading
U = Undisturbed, B = Bulk, D = Disturbed, J = Jar, W = Water, SPT = Split Spoon Sample, C = Core Cutter
Tested in Vertical Condition
UKAS Calibration - loads from 0.2 to 10kN
Sample disturbance, loss of moisture, variation form test procedure, location and origin of test specimen within original sample, oven drying
temperature if not 105-110°C
www.soilpropertytesting.com
Page 12 of 12
Element Materials Technology
P: +44 (0) 1244 833780
Unit 3 Deeside Point
F: +44 (0) 1244 833781
Zone 3
Deeside Industrial Park
W: www.element.com
Deeside
CH5 2UA
EPS Ltd
7B Caxton House
Broad Street
Cambourne
Cambridgeshire
CB23 6JN
Attention :
Daryl Bowell
Date :
1st September, 2020
Your reference :
UK20.5082
Our reference :
Test Report 20/11448 Batch 1
Location :
Queens Walk Wembley
Date samples received :
27th August, 2020
Status :
Final report
Issue :
1
Eight samples were received for analysis on 27th August, 2020 of which six were scheduled for analysis. Please find attached our Test Report which
should be read with notes at the end of the report and should include all sections if reproduced. Interpretations and opinions are outside the scope of
any accreditation, and all results relate only to samples supplied.
All analysis is carried out on as received samples and reported on a dry weight basis unless stated otherwise. Results are not surrogate corrected.
Authorised By:
Phil Sommerton BSc
Senior Project Manager
Please include all sections of this report if it is reproduced
Element Materials Technology Environmental UK Limited
Registered in England and Wales
Registered Office: 10 Lower Grosvenor Place, London, SW1W 0EN
Company Registration No: 11371415
1 of 6
Element Materials Technology
EPS Ltd
UK20.5082
Queens Walk Wembley
Daryl Bowell
Client Name:
Reference:
Location:
Contact:
EMT Job No:
Report : Solid
Solids: V=60g VOC jar, J=250g glass jar, T=plastic tub
20/11448
EMT Sample No.
Sample ID
Depth
1
2
3
4
5
6
BH01 SD4
BH01 SD5
BH01 SD8
BH01 SD10
BH01 SD12
BH01 SD14
3-3.45
5-5.45
9-9.45
12-12.45
T
T
T
T
16.5-16.95 19.5-19.45
COC No / misc
Containers
T
Please see attached notes for all
abbreviations and acronyms
T
Sample Date 17/08/2020 17/08/2020 17/08/2020 17/08/2020 17/08/2020 17/08/2020
Sample Type
Batch Number
Clay
Clay
Clay
Clay
Clay
Clay
1
1
1
1
1
1
LOD/LOR
Units
Method
No.
Date of Receipt 27/08/2020 27/08/2020 27/08/2020 27/08/2020 27/08/2020 27/08/2020
0.76
0.17
0.29
0.39
0.34
0.51
<0.01
%
TM30/PM15
20110AA
3770
7412
1675
1594
1879
<50
mg/kg
TM50/PM29
2.6013
1.3920
2.8578
0.6388
0.5629
0.6908
<0.0015
g/l
TM38/PM20
pH #M
7.77
8.06
7.72
8.28
8.34
8.21
<0.01
pH units
TM73/PM11
Sample Type
Clay
Clay
Clay
Clay
Clay
Clay
None
PM13/PM0
None
PM13/PM0
None
PM13/PM0
Sulphur as S
Total Sulphate as SO4 #M
Sulphate as SO4 (2:1 Ext) #M
Sample Colour
Other Items
QF-PM 3.1.2 v11
Medium Brown Medium Brown Medium Brown Medium Brown Medium Brown Medium Brown
chalk
stones
stones
stones
stones
stones
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All solid results are expressed on a dry weight basis unless stated otherwise.
2 of 6
Element Materials Technology
Client Name:
Reference:
Location:
Contact:
EMT
Job
No.
Batch
Notification of Deviating Samples
EPS Ltd
UK20.5082
Queens Walk Wembley
Daryl Bowell
Sample ID
Depth
EMT
Sample
No.
Analysis
Reason
No deviating sample report results for job 20/11448
Please note that only samples that are deviating are mentioned in this report. If no samples are listed it is because none were deviating.
Only analyses which are accredited are recorded as deviating if set criteria are not met.
QF-PM 3.1.11 v3
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3 of 6
NOTES TO ACCOMPANY ALL SCHEDULES AND REPORTS
EMT Job No.:
20/11448
SOILS
Please note we are only MCERTS accredited (UK soils only) for sand, loam and clay and any other matrix is outside our scope of accreditation.
Where an MCERTS report has been requested, you will be notified within 48 hours of any samples that have been identified as being outside our
MCERTS scope. As validation has been performed on clay, sand and loam, only samples that are predominantly these matrices, or combinations
of them will be within our MCERTS scope. If samples are not one of a combination of the above matrices they will not be marked as MCERTS
accredited.
It is assumed that you have taken representative samples on site and require analysis on a representative subsample. Stones will generally be
included unless we are requested to remove them.
All samples will be discarded one month after the date of reporting, unless we are instructed to the contrary.
If you have not already done so, please send us a purchase order if this is required by your company.
Where appropriate please make sure that our detection limits are suitable for your needs, if they are not, please notify us immediately.
All analysis is reported on a dry weight basis unless stated otherwise. Limits of detection for analyses carried out on as received samples are not
moisture content corrected. Results are not surrogate corrected. Samples are dried at 35°C ±5°C unless otherwise stated. Moisture content for
CEN Leachate tests are dried at 105°C ±5°C.
Where Mineral Oil or Fats, Oils and Grease is quoted, this refers to Total Aliphatics C10-C40.
Where a CEN 10:1 ZERO Headspace VOC test has been carried out, a 10:1 ratio of water to wet (as received) soil has been used.
% Asbestos in Asbestos Containing Materials (ACMs) is determined by reference to HSG 264 The Survey Guide - Appendix 2 : ACMs in buildings
listed in order of ease of fibre release.
Sufficient amount of sample must be received to carry out the testing specified. Where an insufficient amount of sample has been received the
testing may not meet the requirements of our accredited methods, as such accreditation may be removed.
Negative Neutralization Potential (NP) values are obtained when the volume of NaOH (0.1N) titrated (pH 8.3) is greater than the volume of HCl (1N)
to reduce the pH of the sample to 2.0 - 2.5. Any negative NP values are corrected to 0.
The calculation of Pyrite content assumes that all oxidisable sulphides present in the sample are pyrite. This may not be the case. The calculation
may be an overesitimate when other sulphides such as Barite (Barium Sulphate) are present.
WATERS
Please note we are not a UK Drinking Water Inspectorate (DWI) Approved Laboratory .
ISO17025 accreditation applies to surface water and groundwater and usually one other matrix which is analysis specific, any other liquids are
outside our scope of accreditation.
As surface waters require different sample preparation to groundwaters the laboratory must be informed of the water type when submitting samples.
Where Mineral Oil or Fats, Oils and Grease is quoted, this refers to Total Aliphatics C10-C40.
DEVIATING SAMPLES
All samples should be submitted to the laboratory in suitable containers with sufficient ice packs to sustain an appropriate temperature for the
requested analysis. The temperature of sample receipt is recorded on the confirmation schedules in order that the client can make an informed
decision as to whether testing should still be undertaken.
SURROGATES
Surrogate compounds are added during the preparation process to monitor recovery of analytes. However low recovery in soils is often due to peat,
clay or other organic rich matrices. For waters this can be due to oxidants, surfactants, organic rich sediments or remediation fluids. Acceptable
limits for most organic methods are 70 - 130% and for VOCs are 50 - 150%. When surrogate recoveries are outside the performance criteria but
the associated AQC passes this is assumed to be due to matrix effect. Results are not surrogate corrected.
DILUTIONS
A dilution suffix indicates a dilution has been performed and the reported result takes this into account. No further calculation is required.
BLANKS
Where analytes have been found in the blank, the sample will be treated in accordance with our laboratory procedure for dealing with contaminated
blanks.
NOTE
Data is only reported if the laboratory is confident that the data is a true reflection of the samples analysed. Data is only reported as accredited when
all the requirements of our Quality System have been met. In certain circumstances where all the requirements of the Quality System have not been
met, for instance if the associated AQC has failed, the reason is fully investigated and documented. The sample data is then evaluated alongside
the other quality control checks performed during analysis to determine its suitability. Following this evaluation, provided the sample results have not
been effected, the data is reported but accreditation is removed. It is a UKAS requirement for data not reported as accredited to be considered
indicative only, but this does not mean the data is not valid.
Where possible, and if requested, samples will be re-extracted and a revised report issued with accredited results. Please do not hesitate to contact
the laboratory if further details are required of the circumstances which have led to the removal of accreditation.
QF-PM 3.1.9 v34
Please include all sections of this report if it is reproduced
All solid results are expressed on a dry weight basis unless stated otherwise.
4 of 6
EMT Job No.:
20/11448
REPORTS FROM THE SOUTH AFRICA LABORATORY
Any method number not prefixed with SA has been undertaken in our UK laboratory unless reported as subcontracted.
Measurement Uncertainty
Measurement uncertainty defines the range of values that could reasonably be attributed to the measured quantity. This range of values has not
been included within the reported results. Uncertainty expressed as a percentage can be provided upon request.
ABBREVIATIONS and ACRONYMS USED
#
ISO17025 (UKAS Ref No. 4225) accredited - UK.
SA
ISO17025 (SANAS Ref No.T0729) accredited - South Africa
B
DR
Indicates analyte found in associated method blank.
Dilution required.
M
MCERTS accredited.
NA
Not applicable
NAD
ND
NDP
No Asbestos Detected.
None Detected (usually refers to VOC and/SVOC TICs).
No Determination Possible
SS
Calibrated against a single substance
SV
Surrogate recovery outside performance criteria. This may be due to a matrix effect.
W
Results expressed on as received basis.
+
AQC failure, accreditation has been removed from this result, if appropriate, see 'Note' on previous page.
>>
Results above calibration range, the result should be considered the minimum value. The actual result could be significantly
higher, this result is not accredited.
*
Analysis subcontracted to an Element Materials Technology approved laboratory.
AD
Samples are dried at 35°C ±5°C
CO
Suspected carry over
LOD/LOR
ME
NFD
Limit of Detection (Limit of Reporting) in line with ISO 17025 and MCERTS
Matrix Effect
No Fibres Detected
BS
AQC Sample
LB
Blank Sample
N
Client Sample
TB
Trip Blank Sample
OC
Outside Calibration Range
AA
x5 Dilution
QF-PM 3.1.9 v34
Please include all sections of this report if it is reproduced
All solid results are expressed on a dry weight basis unless stated otherwise.
5 of 6
Element Materials Technology
EMT Job No:
Method Code Appendix
20/11448
Test Method No.
Prep Method
No. (if
appropriate)
Description
Description
ISO
MCERTS
17025
(UK soils
(UKAS/S
only)
ANAS)
Analysis done
on As Received
(AR) or Dried
(AD)
Reported on
dry weight
basis
PM13
A visual examination of the solid sample is carried out to ascertain sample make up,
colour and any other inclusions. This is not a geotechnical description.
PM0
No preparation is required.
AR
No
TM30
Determination of Trace Metals by ICP-OES (Inductively Coupled Plasma – Optical
Emission Spectrometry): WATERS by Modified USEPA Method 200.7, Rev. 4.4, 1994;
Modified EPA Method 6010B, Rev.2, Dec 1996; Modified BS EN ISO 11885:2009:
SOILS by Modified USEP
PM15
Acid digestion of dried and ground solid samples using Aqua Regia refluxed at 112.5 °C.
Samples containing asbestos are not dried and ground.
AD
Yes
TM38
Soluble Ion analysis using Discrete Analyser. Modified US EPA methods: Chloride 325.2
(1978), Sulphate 375.4 (Rev.2 1993), o-Phosphate 365.2 (Rev.2 1993), TON 353.1
(Rev.2 1993), Nitrite 354.1 (1971), Hex Cr 7196A (1992), NH4+ 350.1 (Rev.2 1993
(comparabl
PM20
Extraction of dried and ground or as received samples with deionised water in a 2:1
water to solid ratio using a reciprocal shaker for all analytes except hexavalent
chromium. Extraction of as received sample using 10:1 ratio of 0.2M sodium hydroxide to
soil for hexavalent chromium using a reciprocal shaker.
Yes
Yes
AD
Yes
TM50
Acid soluble sulphate (Total Sulphate) analysed by ICP-OES
PM29
A hot hydrochloric acid digest is performed on a dried and ground sample, and the
resulting liquor is analysed.
Yes
Yes
AD
Yes
TM73
Modified US EPA methods 150.1 (1982) and 9045D Rev. 4 - 2004) and BS13773:1990. Determination of pH by Metrohm automated probe analyser.
PM11
Extraction of as received solid samples using one part solid to 2.5 parts deionised water.
Yes
Yes
AR
No
QF-PM 3.1.10 v14
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6 of 6