Site Investigation Report

Site: Down Sports Field, School Lane, , TN22 4JD

Client: Hadlow Down Community Centre

Report Date: 15 July 2013

Project Reference: J11197

SUMMARY The site, which extends to about 1.5 ha, comprises an open area of grass containing play equipment, a cricket pitch, a cricket pavilion, and playing field. The site currently has poor drainage which is affecting its use. It is proposed to install a drainage system, as well as eventually constructing a new village centre. Geological records indicate the site to be underlain by the Clay in the north, and the Tunbridge Wells Sands to the south. A single phase of intrusive investigation was carried out. The soils encountered comprised a thin covering of clay topsoil overlying stiff weathered clays to about 1.5 m, and then with stiff to very stiff clays overlying weak to moderately strong sandstones. A safe bearing capacity of about 125 kN/m 2 at 1.8 m is recommended. No groundwater was encountered during this investigation. Contamination issues are not considered in this report. The site investigation was conducted and this report has been prepared for the sole internal use and reliance of Hadlow Down Community Centre and their appointed Engineers. This report shall not be relied upon or transferred to any other parties without the express written authorization of Southern Testing Laboratories Limited. If an unauthorised third party comes into possession of this report they rely on it at their peril and the authors owe them no duty of care and skill. The findings and opinions conveyed via this Site Investigation Report are based on information obtained from a variety of sources as detailed within this report, and which Southern Testing Laboratories Ltd believes are reliable. Nevertheless, Southern Testing Laboratories Ltd cannot and does not guarantee the authenticity or reliability of the information it has obtained from others.

Morris Stevenson MICE Tom Lees MSc FGS (Countersigned) (Signed) For and on behalf of Southern Testing Laboratories Limited STL: J11197 15 July 2013

TABLE OF CONTENTS AAA INTRODUCTIONINTRODUCTION...... 1111 1 AUTHORITY ...... 1 2 LOCATION ...... 1 3 PROPOSED CONSTRUCTION ...... 1 4 OBJECT ...... 1 5 SCOPE ...... 1 BBB WALKOVER SURVEY & PRPRELIMINARYELIMINARY INFORMATIOINFORMATIONNNN ...... 2222 6 GEOLOGY ...... 2 7 RADON RISK ...... 3 8 WALKOVER SURVEY ...... 3 CCC SITE INVESTIGATION ...... 4...... 444 9 METHOD ...... 4 10 WEATHER CONDITIONS ...... 4 11 SOILS AS FOUND ...... 4 12 GROUNDWATER STRIKES ...... 4 DDD FIELD TESTING AND SASAMPLINGMPLING ...... 5555 EEE GEOTECHNICAL LABORATLABORATORYORY TESTS ...... 5...... 555 FFF DISCUSSION OF GEOTECGEOTECHNICALHNICAL TEST RESULTS AND RECOMMENDATIONS ...... 5...... 555 13 SOIL CLASSIFICATION AND PROPERTIES ...... 5 14 SWELLING AND SHRINKAGE ...... 5 15 LATERAL PRESSURES & HEAVE ...... 8 16 GROUNDWATER LEVELS ...... 8 17 SOAKAWAYS ...... 8 18 SULPHATES AND ACIDITY ...... 8 19 BEARING CAPACITY ...... 8 20 EXCAVATIONS AND TRENCHING ...... 8 21 SLOPE STABILITY ...... 8

APPENDIX A Site Plans and Exploratory Hole Logs APPENDIX B Field Sampling and in-situ Test Methods & Results APPENDIX C Geotechnical Laboratory Test Methods & Results

AAA INTRODUCTION

111 Authority

Our authority for carrying out this work is contained in a Project Order form from Hadlow Down Community Centre, received on the 8 th May 2013.

222 Location

The site is located 0.4 km north of St Mark’s Church in Hadlow Down, 7 km south of . The approximate National Grid Reference of the site is TQ 527 246.

333 Proposed Construction

It is proposed to install a drainage system into the upper area of the playing field, as well as construct a new village centre. Ground loadings for the new building have not been given.

444 Object

This is a geotechnical investigation.

The object of the investigation was to assess foundation bearing conditions and other soil parameters relevant to the proposed development, and to assess the potential options for soakage within the playing field.

555 Scope

This report presents our exploratory hole logs and test results and our interpretation of these data. As with any site there may be differences in soil conditions between exploratory hole positions.

This report is not an engineering design and the figures and calculations contained in the report should be used by the Engineer, taking note that variations will apply, according to variations in design loading, in techniques used, and in site conditions. Our figures therefore should not supersede the Engineer's design.

Contamination issues are not considered in this report.

The findings and opinions conveyed via this Site Investigation Report are based on information obtained from a variety of sources as detailed within this report, and which Southern Testing Laboratories Limited believes are reliable. Nevertheless, Southern Testing Laboratories Limited cannot and does not guarantee the authenticity or reliability of the information it has obtained from others.

The site investigation was conducted and this report has been prepared for the sole internal use and reliance of Hadlow Down Community Centre and their appointed Engineers. This report shall not be relied upon or transferred to any other parties without the express written authorization of Southern Testing Laboratories Limited. If an unauthorised third party comes into possession of this report they rely on it at their peril and the authors owe them no duty of care and skill.

J11197 – Hadlow Down Sports Field 1 15 July 2013

The recommendations contained in this report may not be appropriate to alternative development schemes.

BBB WALKOVER SURVEY & PRELIMINARY INFORMINFORMATIONATION

666 Geology

The British Geological Survey Map No 303 indicates that the site geology consists of the Tunbridge Wells Sands Formation to the south, with the Wadhurst Clay to the north.

Wadhurst Clay

The Wadhurst Clay is similar to other Wealden Clays and consists of dark grey shale, mudstones, and pale grey silty mudstones with subordinate beds of silt, sandstone, shelly limestone and clay ironstone. A thin band of red shale, coloured by disseminated haematite, usually marks the top of the Wadhurst Clay. Similar colouring is occasionally found beds of stone within the formation.

At the surface the Wadhurst Clay is stiff (high strength) silty plastic clay that becomes rapidly stiffer with depth becoming a weak rock at about 4-6 metres depth.

The clay ironstone was extensively worked up until the early 19th century and old workings are common in many areas, particularly near the junction with the underlying Ashdown Sand. The sides of the larger pits were often left at a steep angle and these are generally found to be unstable. Smaller 'bell pits' were usually infilled and may only be distinguished by a shallow depressions in the ground surface at the present day.

Wadhurst Clay is often found to line the valley bottoms in Tunbridge Wells Sand areas and may be distorted by valley bulging, because of water seepage at the interface between the two series, and because of the pressure from the sandstone escarpments.

Tunbridge Wells Sand (Undivided)

This formation consists of variegated soft mudstones, clays, silts, thinly bedded sandstones and occasional clay ironstones which were laid down at the outermost part of the Tunbridge Wells Sand delta, as it encroached on the Wealden Lake. The deposits are characteristically lenticular and impersistent, meaning that variability is to be expected. The clays commonly weather to red and the silts to mottled grey and orange ("catsbrain"). There are seams of harder rock from place to place, which cause difficulties to mechanical plant and may require drilling and blasting for economic excavation.

An important feature of the sandstone is that it is subject to "cambering". On and near steep hill slopes cracks and fissures have been formed because of movement in the underlying Wadhurst Clay. These are usually in two directions, parallel to, and at right angles to, the line of the escarpment, and range from a few mm wide, to a metre wide, or more. The fissures are often infilled with silt but are occasionally open (voids). There have been instances of the fissures opening up after soakaways have been installed nearby.

J11197 – Hadlow Down Sports Field 2 15 July 2013

777 Radon Risk

With reference to BRE guidance no radon protection is required on this site.

888 Walkover Survey

A walkover survey was carried out on 10 th June 2013.

8.18.18.1 General DeDescriptionscription and Boundaries The site is an L-shaped area of land. Access to the site is from the east, through wooden gates off School Lane. The site generally comprises open grass areas used for recreational purposes.

The eastern part of the site contains children’s play equipment and a small gravelled car park. A gravel access road leads up to the rest of the site, which is separated from the eastern area by a ditch, a bank and a line of trees. The western part of the site contains the main open spaces, including a cricket pitch to the north and open grass area to the south.

The site is surrounded by hedgerows containing mature deciduous trees. On the eastern side the site borders with School Lane, and is separated by a wooden fence.

8.28.28.2 Topography and Drainage The southern open grass area is generally level, with a slight slope to the north east. The cricket pitch in the north slopes gently to the north east, becoming gradually steeper towards the north east. A bank approximately 1 m high separates the cricket pitch and main grass area.

The eastern part of the site (containing the play equipment) slopes to the north east at approximately 2 - 3 degrees.

There is an excavated area approximately 3 m deep at the top of the access road, where a small basketball court has been constructed. A small area of concrete hard standing is also present in this location.

A ditch runs around the perimeter of the site, and along the divide between the eastern part and main site area. Several land drains were observed draining from the cricket pitch area into this dividing ditch.

The field to the west of the southern part of the site is approximately 1.5 m higher topographically. It appears that the playing field was created by cutting material out in order to produce a level surface.

8.38.38.3 Vegetation The hedgerows that run around the site contain mixed bushes and shrubs, as well as many mature Oak trees. In the area of the proposed new community centre there are several mature Oak trees. Along the eastern border there are mature Pine trees.

8.48.48.4 Buildings and Land Use on Site and Nearby The site is situated in a predominantly rural area. There are residential properties to the east of the site. The remaining borders are with open field.

J11197 – Hadlow Down Sports Field 3 15 July 2013

CCC SITE INVESTIGATION

999 Method

The strategy adopted for the intrusive investigation comprised the following:

• A series of 4 test pits was excavated using a hydraulic backhoe excavator.

• 1 soakage test was carried out using the BRE365 method.

Exploratory hole locations are shown in Figure N in Appendix A.

101010 Weather Conditions

The fieldwork was carried out on the 10 th June 2013 at which time the weather was generally dry.

111111 Soils as Found

The soils encountered are described in detail in the attached exploratory hole logs (Appendix A), but in general comprised a covering of topsoil over stiff to very stiff clay, over Weak to moderately strong sandstone. A summary is given below.

Depth Thickness Soil Type Description GL to 0.15 / 0.3 m Up to 300 mm TOPSOIL Firm grey brown clay with frequent fine rootlets. 0.15/0.3 to About 1.2 m CLAY Stiff becoming very stiff slightly 1.4/1.5 m silty to sandy clay. 1.4/1.5 to 0.5/0.8 m CLAY Very stiff to hard sandy clay with 1.9/2.3 m fine grained sandstone gravels. 1.9/2.3 m to 0.4 m + SANDSTONE Weak to moderately strong 2.3/2.6 m laminated sandstone with some iron staining.

121212 Groundwater Strikes

No groundwater was encountered during this investigation.

J11197 – Hadlow Down Sports Field 4 15 July 2013

DDD FIELD TESTING AND SASAMPLINGMPLING

The following in-situ test and sampling methods were employed. Descriptions are given in Appendix B together with the test results .

• Collection of disturbed samples;

• Perth Penetrometer Testing;

• Hand Penetrometer Testing;

• BRE365 soakage tests.

EEE GEOTECHNICAL LABORATORY TESTS

The following tests were carried out on selected samples. Test method references and results are given in Appendix C.

• Natural Moisture Content;

• Plasticity Index (Atterberg Limits);

• pH value of soil;

• Water soluble sulphate content of soil.

FFF DISCUSSION OF GEOTECGEOTECHNICALHNICAL TEST RESULTS AND RECOMMENDATIONS

131313 Soil Classification and PropertPropertiesiesiesies

Frost Soil Type Depth (m) Compressibility VCPVCPVCP Permeability Susceptible

Clay 0.2/0.3 – Medium Medium Very low Possible 1.4/1.5 Clay 1.41.5 – Low Low Very low Possible 1.9/2.3 Sandstone 1.9/2.3 + N/A N/A Appears low in Possible top 0.5 m

141414 Swelling and Shrinkage

Clay of Intermediate Plasticity (below topsoil to about 1.51.51.5 m)m)m) With measured liquid limits in the range 37 to 44 % and plasticity indices from18 to 24 % the soil is classified as a (CI) clay of intermediate plasticity.

J11197 – Hadlow Down Sports Field 5 15 July 2013

The anticipated properties of the soil are:

1. They have moderate to high swelling and shrinkage properties and fall into the NHBC MEDIUM VCP classification group. 2. They are potentially frost susceptible unless full frost susceptibility tests to BS 812 Part 124 indicates otherwise. 3. They have poor drainage characteristics.

Clay of Low Plasticity (below about 1.51.51.5m)1.5 m)m)m) With a measured liquid limit of 30 % and a plasticity index of 12 % the clay below about 2.0 m is classified as a (CL) clay of low plasticity in the BSCS classification or clay silt in the Casagrande system.

The anticipated properties of the soil are:

1. They have moderate swelling and shrinkage properties, and fall into the NHBC LOW VCP group. 2. They are potentially frost susceptible unless full frost susceptibility tests to BS 812 Part 124 indicates otherwise. 3. They have poor drainage characteristics.

An NHBC MEDIUM Volume Change Potential classification should be adopted for the clays above 1.5 m. Given the near proximity of the proposed community centre to mature oak trees our calculations indicate that foundations should be dug to a depth of 1.8 m below ground level. This may mean founding on the underlying sandstone. Full details of protective measures are available in NHBC 4.2, but for convenience the depth requirements are summarised below.

NHBC MEDIUM VCP – clays to 1.5 m

Table of Foundation Depths. . . . Deciduous Trees. . . . Medium Volume Change Potential

Distance from the dwelling as a proportion of the tree height.

(D/H Ratio) 0.0 0.1 0.2 0.4 0.5 0.7 1.0 1.25

Tree Species Depth of foundation in m

Oak, Poplar, Willow, * * * 2.3 2.2 1.8 1.3 0.9 Hawthorn, Elm, Eucalyptus.(High demand)

Ash, Plane, Cherry, Fruit, 2.0 1.85 1.7 1.4 1.25 1.0 0.9 0.9 Beech (Moderate demand)

Holly, Magnolia, 1.5 1.4 1.25 1.0 0.9 0.9 0.9 0.9 Mulberry, Shrubs (Low demand)

J11197 – Hadlow Down Sports Field 6 15 July 2013

Table of Foundation Depths. . . Conifers . . Medium Volume Change Potential.

Distance from dwelling as a proportion of the tree height

(D/H Ratio) 0.0 0.1 0.2 0.3 0.35 0.4 0.5 0.6

Tree Species Depth of foundation in m

Lawsons, Leyland, Monterey * * 2.3 1.95 1.8 1.6 1.25 0.9 Cypress (High Demand)

Cedar, Pine, Spruce, Douglas 2.0 1.7 1.35 1.05 0.9 0.9 0.9 0.9 Fir, Wellingtonia & Yew (Moderate Demand)

NHBC LOW VCP – clays 1.5 m to about 1.9 m

Table of Foundation Depths. . . Deciduous Trees. . . . Low Volume Change Potential

Distance from the dwelling as a proportion of the tree height

(D/H Ratio) 0.0 0.1 0.2 0.4 0.5 0.7 1.0 1.25

Tree Species Depth of foundation in metres/mm

Oak, Poplar, Willow, 2.5 2.4 2.2 1.95 1.8 1.5 1.1 750 Hawthorn, Elm, Eucalyptus.(High demand)

Ash, Plane, Cherry, Fruit, 1.6 1.5 1.4 1.15 1.0 800 750 750 Beech (Moderate demand)

Holly, Magnolia, 1.2 1.1 1.0 850 750 750 750 750 Mulberry, Shrubs (Low demand)

Table of Foundation Depths. . . Conifers . . . . . Low Volume Change Potential.

Distance from dwelling as a proportion of the tree height

(D/H Ratio) 0.0 0.1 0.2 0.3 0.35 0.4 0.5 0.6

Tree Species Depth of foundation in metres/mm

Lawsons, Leyland, Monterey 2.5 2.2 1.9 1.65 1.5 1.35 1.05 0.75 Cypress (High Demand)

Cedar, Pine, Spruce, Douglas 1.6 1.35 1.1 0.85 0.75 0.75 0.75 0.75 Fir, Wellingtonia & Yew (Moderate Demand)

Foundations below 2.5m must be designed individually by an engineer on an individual property basis taking into account soil desiccation, lateral pressure, trench stability and workmanship. At depths in excess of 2.5m a piled foundation is usually the most appropriate foundation.

Where trees have been or are to be removed from within 2m of the face of the excavation and where the height on removal is less than 50% of the maturity then distance (D) can be assumed to be 2m. This is to cater for the occurrence of ‘saplings’.

J11197 – Hadlow Down Sports Field 7 15 July 2013

151515 Lateral Pressures & Heave Where foundations are more than 1.5m deep, and are within the zone of influence of existing or removed trees, then precautions will also need to be taken against the effects of lateral swelling of soils beneath house units due to removal of trees, or cutting tree roots. The NHBC requirements for the relief of lateral pressure are set out in Chapter 4.2 of the NHBC Standards Manual, as revised in October 2003, and to which the reader is referred. The basic requirement is that compressible material or void former should be installed on the inner face of external foundation walls. With pier and beam foundations additional voids are required below ring beams. In all cases where deep foundations are adopted, special precautions may be required to prevent damage to roots of retained trees. The heave will have a significant effect on drains and services. Flexible entry points to structures will minimise fracturing but will not affect or prevent backfalls in drains or the like.

161616 Groundwater Levels Groundwater levels vary considerably from season to season and year to year, often rising close to the ground surface in wet or winter weather, and falling in periods of drought. Long-term monitoring from boreholes or standpipes is required to assess the ground water regime and this was not possible during the course of this site investigation. No groundwater was encountered during this investigation.

171717 Soakaways The results of the BRE 365 soakage test indicate very poor soakage conditions within the clay and top of the underlying sandstone. The water level in the test pit did not drop throughout the test period. The infiltration rate of the underlying sandstone may be greater at depth than that found in this investigation. Construction of deeper trenches into the top of the sandstone, or deep borehole soakaways may allow for better infiltration rates. Further investigation would be required to confirm this.

181818 Sulphates and Acidity The clay at 1.5 m depth in TP4 were found to have a pH of 4.6. The Design Sulphate Class is DS-1. Groundwater should be assumed to be mobile. The ACEC site classification is AC2z.

191919 Bearing Capacity A bearing capacity of about 125 kN/m 2 in the clays at 1.8m is recommended. The bearing capacity of the underlying sandstone is likely to be in excess of 250 kN/m 2. Minimum trench width should be 450 mm.

202020 Excavations and Trenching Statutory support will be required in all excavations where personnel must work.

The clay soils may soften significantly when saturated and therefore pit instability may be an issue if ground works are undertaken during a particularly wet period. Close support may be required depending on the weather prior to and during the ground works.

212121 Slope Stability No indication of slope instability was noted during this site investigation.

J11197 – Hadlow Down Sports Field 8 15 July 2013 APPENDIX A

Site Plans and Exploratory Hole Logs

TEST HOLE LOG National Grid Reference TQ 527 246 Job No J11197 Date 10/06/2013 Site : School Lane, Hadlow Down Logged by TRL Engineer TRL

Client : Hadlow Down Parish Council Excavation Method : JCB 3CX

Water strikes: Hole No Water strikes: Hole No Dry TP1 Dry TP2 Water level: Water level: Pit sides: Stable Pit sides: Stable

Depth Depth or Test Type & Value Key Soil Description or Test Type & Value Key Soil Description Sample Type Sample Type Sample Depth Depth m/mm (Thickness) Depth m/mm (Thickness)

TOPSOIL Firm grey brown clay TOPSOIL (200) TOPSOIL Firm brown occasionally veined 150 with frequent fine rootlets. red brown slightly silty clay CLAY 200 Very stiff to hard orange brown CLAY TOPSOIL with frequent fine

mottled light grey slightly silty rootlets.

T T CLAY, in places slightly friable. 500 B 500 D Stiff orange brown mottled light 600 290 grey sandy CLAY with occasional From 1.5 m becoming slightly cobbles of very weak fine sandy with occasional moderately sandstone, and rare iron staining.

strong fine sandstone fragments. (1.2) T

1.01.01.0 B T 1.01.01.0 D 390 37 190 25

(2.0)

T T 1.4 CLAY Very stiff to hard light grey 1.51.5 B 1.51.5 D 600 600 mottled orange brown CLAY. In places thinly bedded.

1.8 From 1.8 m with frequent thin

37 (900)

T 1.9 T beds of ironstone. 50 2.0 2.02.0 D 600 for 600 350 2.1 2.2 B mm SANDSTONE Weak thickly laminated to thinly (300) bedded light grey fine SANDSTONE with occasional iron 2.3 2.4 B 2.4 2.4 D 2.4 SANDSTONE Moderately strong thinly bedded staining and ironstone slightly clayey fine SANDSTONE laminations, and occasional thick with occasional iron staining. laminations of very stiff orange brown mottled light grey clay.

Water strikes: Hole No Water strikes: Hole No Dry TP3 Dry TP4 Water level: Water level: Pit sides: Stable Pit sides: Stable

Depth Depth or or Test Type & Value Key Soil Description Test Type & Value Key Soil Description Sample Type Sample Type Sample Depth Depth m/mm Depth Depth m/mm (Thickness) (Thickness)

(200) TOPSOIL Firm brown clay TOPSOIL with TOPSOIL Firm brown clay TOPSOIL with frequent fine rootlets. (300) frequent fine rootlets. 200 CLAY Very stiff to hard orange brown 300

mottled light grey slightly silty CLAY Firm to stiff yellow brown silty

T T CLAY. In places slightly friable. (300) CLAY with occasional iron stained 500 D 500 D 510 170 spots. From 1.5 m with occasional 600 CLAY Very stiff light grey mottled orange cobbles of moderately strong

thinly laminated fine sandtstone, brown slightly silty CLAY with

occasional cobbles of moderately

T T and with occasional iron staining. strong fine sandstone and 1.01.01.0 D 1.01.01.0 D 600 50 (1.7) 600 39 occasional patches of ironstone. for 400

mm

T T (1.7) 1.51.5 D 1.51.5 D

600 600 1.8 T 50 1.9 1.9 600 for 2.0 D 300 SANDSTONE Moderately strong orange brown 2.02.0 D mm to yellow brown thinly bedded 50 (400) slightly silty fine SANDSTONE for with occasional bands of iron 400 2.3 D 2.3 staining and occasional thick mm 2.3 laminations of very stiff clay. SANDSTONE Moderately strong yellow brown (300) thickly laminated to thinly bedded 2.5 D fine SANDSTONE with occasional 2.6 iron staining on surfaces and occasional thick laminations to thin beds of very stiff clay.

* : Perth Penetration Test, 'N' value; : Penetration Test, 'N' values; T : Unconfined Compression Strength by hand penetrometer, kN/m2; V : Shear Vane test, kN/m2; X : CBR by Mexe cone penetrometer, %; D: Disturbed sample; U: Undisturbed sample; B: Bulk sample; W: Water sample APPENDIX B

Field Sampling and in-situ Test Methods & Results Field Sampling and inin----situsitu Test Methods

Disturbed Samples Disturbed samples were taken from the trial holes intervals and stored in sealed glass jars and polythene bags, as appropriate.

Undisturbed U100 Samples Undisturbed U100 samples were taken in the clay soils at appropriate intervals. These samples are taken in a 100 mm diameter, 450 mm long, thin-walled steel tube, and are sealed with paraffin wax and tightly fitting end caps for transporting to the laboratory.

Standard Penetration Test The Standard Penetration (SPT) Test is specified in BS EN ISO 22476-3 : 2005. In this test, a 51mm diameter open-ended tube is driven into the ground by a 63.5 kg hammer falling freely through 760 mm. The tube is seated by driving to a penetration of 150mm, or by 25 standard blows, whichever occurs first. It is then driven for a maximum of a further 300mm and the number of blows is termed the penetration resistance (N). If 300mm penetration cannot be achieved in 50 blows (100 blows in soft rock), the test drive is terminated. When testing in gravels, a conical end piece is attached to the tube. The test is then called an SPT(C). This test provides an indirect method of assessing the properties of cohesionless soils, and the following table (after Terzaghi and Peck) gives the approximate condition:-

Number Blows (N) Density 0 - 4 Very Loose 4 – 10 Loose 10 – 30 Medium Dense 30 – 50 Dense Over 50 Very Dense ClayClayClay An approximate value for the shear strength of clay may be obtained using Stroud (1974), which paper indicates that the cohesive strength is a function of plasticity and SPT 'N' value. The relation is:

Cu = fi x N kPa

Cu = undrained shear strength fi = factor related to plasticity index and ranging from 4 to more than 6 The SPT test is not generally accepted as giving a reliable indication of the strength of cohesive soils but it does give a guide; often the following table:-

Number Blows (N) Soil Strength Less than 2 Very Soft (Very Low Strength) 2 – 5 Soft (Low Strength) 5 – 10 Firm (Medium Strength) 10 – 15 Stiff (High Strength) 15 – 30 Very Stiff (Very High Strength) Perth Penetrometer Test Perth Penetrometer tests were carried out. The Perth Penetrometer is a device used for measuring the relative density of sands. It consists of a 16 mm diameter hardened steel probe, which is driven into the soil by successive blows of a 9 kg weight, which freely falls over a distance of 600 mm. The number of blows required for each 50 mm of penetration is recorded, and the test is continued for a depth of 450 mm, according to soil type. Useful information can be obtained by carrying the test past the standard depth, and 2,000 mm and 3,000 mm extensions are used to probe the depth of loose fill or other soil, or to make an estimate of the strength of soils or rock in an auger hole or in the base of an unsupported test pit. The energy input per square metre is roughly the same as the energy input from the Standard Penetration Test (SPT), and the blow counts recorded in sand are roughly the same as SPT blow counts (but this relationship does not hold for coarse soils). The SPT test is a similar type of test except that much heavier driving weights (63.5 kg) are used. The relative density relationship given for the SPT test is:

Number of Blows (N) Density 0 - 4 Very Loose 4 - 10 Loose 10 - 30 Medium Dense 30 - 50 Dense Over 50 Very Dense Soakage Tests after BRE 365 (1991) The BRE 365 paper on soakaway design allows for the design of trench soakaways as well as traditional square and circular soakaways. The test to measure the soil infiltration rate is carried out in pits which are excavated to the full depth of the proposed soakaway. The trial pits are filled and allowed to drain to empty or near empty, three times, on the same day or on consecutive days. The pit is considered full when the water level is the same as the proposed inlet invert. The time for the water level to fall from ¾ full to ¼ full is obtained and the soil infiltration rate is obtained from the following formula:

V p75 - 25 =f a p50 x t p75 - 25 Where: f = soil infiltration rate (in this case expressed in l/m²/minute) Vp75-25 = the effective storage volume of water in the trial pit between 75% and 25% effective depth; ap50 = the internal surface area of the trial pit up to 50% effective depth and including the base area; tp75-25 = the time for the water level to fall from 75% to 25% effective depth. The soakage rate in this report in expressed as l/m²/minute, which is a convenient rate to use. The BRE use a unit of m/sec, which is the value in l/m²/minute divided by 60,000. BRE 365 stipulates that the pit should be refilled three times in all, on the same day, or on successive days. Where the sides are unstable the pit should be filled with granular material to provide stability. Where trench soakaways are to be constructed, and the design length is between 10 and 25m a repeat test should be carried out at the end of the proposed soakaway. Where the length is more than 25m the test should be carried out at 25m c/c. Because of time and cost constraints testing was restricted to 1.. . . enter a number . 2 days. As it is a full scale test the BRE 365 test may be expected to give more reliable results than the superseded BRE 151 test, but it is more expensive, takes longer, requires large volumes of water, together with pumps and a specially equipped bowser, and requires a computer program for analysis. It is impractical in areas of restricted access, particularly in the back gardens of existing properties. Southern Testing: Keeble House, Stuart Way, East Grinstead, West RH19 4QA ST Consult: Twigden Barns, Brixworth Road, Creaton, Northampton NN6 8NN

Summary Sheet Results of BRE Digest 365 Soakage Tests

Site : Sports Centre, School Lane, Hadlow Down Job No : J11197

Client : Hadlow Down Parish Council O S Reference : TQ 527 246

Tested By : JT Engineer: MWS Test Date : 10/Jun/2013

Soakage Hole Test Hole Rate for Soakage Rate Water Level No No Depth Each Test for Each Hole at Finish of Test Remarks m litre/m 2 /min litre/m 2 /min m/sec

Water level did not TP1 No 1 2.40 0.0000 0.0000 0.00E+0 fall during test.

Mean Value of All Calculated 0.0000 0.00E+0 Soakage Rates : litre/m 2 /min m/sec Southern Testing: Keeble House, Stuart Way, East Grinstead, West Sussex RH19 4QA ST Consult: Twigden Barns, Brixworth Road, Creaton, Northampton NN6 8NN

BRE Digest 365 Soakage Test

Test Hole No: TP1 Test No: Test No 1 (Initial)

Time from Filling to Maximum Water Depth, minute

0 50 100 150 200 250 300 0.0

Test Results

0.5

1.0 Max Water Depth m

75% Max Water

1.5

50% Max Water

2.0 25% Max Water Depth belowDepth Ground Surface, Bottom of Hole

2.5

3.0

Pit Length, m 1.800 Depth to Water at Start of Test, m 1.090 Pit Width, m 0.450 Max Water Dropdown during Test, m 0.000 Depth to Pit Base, m 2.400 Total Soakage Test Time, min 240.0 Depth to Top of Permeable Soils, m Mean Internal Discharge Area, m 2 6.705 Depth to Groundwater Surface, m Discharge Rate, litre/min 0.000 Depth to Top of Granular Fill, m Soakage Rate, litre/m 2 /min 0.0000 Voids Assumed for Granular Fill, % 100% BRE Soil Infiltration Rate, m/sec 0.00E+00

Comments: Water level did not fall to 75% max water depth, calculations were based on actual fall of water level achieved. Result not compliant with BRE365 requirement since water did not fall to 25% max water depth.

Client: Hadlow Down Parish Council Job No: J11197 Test Date: 10/Jun/2013

Site: Sports Centre, School Lane, Hadlow Down Tested By: JT Engineer: MWS Fig. S1 APPENDIX C

Geotechnical Laboratory Test Methods & Results Southern Testing: Keeble House, Stuart Way, East Grinstead, West Sussex RH19 4QA ST Consult: Twigden Barns, Brixworth Road, Creaton, Northampton NN6 8NN

Soil / Groundwater Sulphate Content Test Results Test carried out in accordance with BS 1377-3:1990 (2003) cl. 5.3, 5.4, 5.6 & 9.5

Project No : J11197 Client : Hadlow Down Parish Council

Project Name : Sports Centre, School Lane, Hadlow Down

Tested By : STL Lab. Checked : CAT Date : 05-Jul-13

Sample Soil Sulphate in Groundwater Total Potential pH Percentage TH No. Depth Visual Description Type 2:1 Water Extract Sulphate Sulphate Value Passing 2mm Sieve BRE BRE BRE (m) g /l SO 3 g /l SO 3 % SO 3 mg /l SO 4 mg /l SO 4 % SO 4

Hard extremely high strength orange TP4 1.50 Soil 0.02 24 4.6 100.0 brown patched light brown and light grey sandy CLAY. Southern Testing: Keeble House, Stuart Way, East Grinstead, West Sussex RH19 4QA ST Consult: Twigden Barns, Brixworth Road, Creaton, Northampton NN6 8NN

Plot Relating Soil Plasticity to NHBC Classification for Volume Change Potential

80 Sample List Statistics

1 TP3@1m Liquid Limit 70 2 [email protected] Max 44 3 TP4@2m Min 30 Average 37

60 Plastic Limit Max 20 Min 18 50 Average 19 NHBC HIGH Volume Change Potential Plasticity Index Max 24 40 Min 12 Average 18 NHBC MEDIUM 30

Plasticity Index (PI), % (PI), Index Plasticity Volume Change Potential

1

20 2 NHBC LOW Volume Change Potential 3 10

0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Liquid Limit (LL), %

Project Name: Sports Centre, School Lane, Hadlow Down Project No: J11197 Project Engineer: TL

Client: Hadlow Down Parish Council Date: 05/07/2013 Figure No. 3 Southern Testing: Keeble House, Stuart Way, East Grinstead, West Sussex RH19 4QA ST Consult: Twigden Barns, Brixworth Road, Creaton, Northampton NN6 8NN

Plasticity Chart for Atterberg Limit Test Results

80 Low Intermediate High Very high Extremely high Sample List Statistics plasticity plasticity plasticity plasticity plasticity (L) (I) (H) (V) (E) 1 TP3@1m Liquid Limit 70 2 [email protected] Max 44 CV CE 3 TP4@2m Min 30 Average 37

60 Plastic Limit CH Max 20 Min 18 50 Average 19 ME Plasticity Index Max 24 40 Min 12 CI Average 18

30 Plasticity Index (PI), % (PI), Index Plasticity MV 1 CL 20 2 MH C represents Clay; 3 M represents Silt; 10 Add 'O' to the symbol for soil SF MI containing a significant amount of organic material e.g. MHO SC ML 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Liquid Limit (LL), %

Project Name: Sports Centre, School Lane, Hadlow Down Project No: J11197 Project Engineer: TL

Client: Hadlow Down Parish Council Date: 05/07/2013 Figure No. 2 Southern Testing: Keeble House, Stuart Way, East Grinstead, West Sussex RH19 4QA ST Consult: Twigden Barns, Brixworth Road, Creaton, Northampton NN6 8NN

Atterberg Limits Test Result Summary Sheet Test carried out in accordance with BS 1377-2:1990(2003) cl. 3.2, 4.2, 4.3, 5.3 & 5.4

Project No : J11197 Checked By : CAT Date: 5-Jul-2013

Project Name : Sports Centre, School Lane, Hadlow Down

Client : Hadlow Down Parish Council

% Plot Moisture Liquid Plastic Plasticity Class- TH No. Depth Passing Visual Description No Content Limit Limit Index ification 425µm (m) (%) (%) (%) (%) (%)

Very stiff very high strength cream 1 TP3 1.00 18.6 44 20 24 CI 95 patched light orange sandy CLAY with occasional sandstone gravel.

Very stiff extremely high strength 2 TP3 1.50 12.7 37 19 18 CI 100 pale grey mottled light brown and orange sandy CLAY. Light grey patched orange yellow slightly sandy CLAY with frequent 3 TP4 2.00 12.3 30 18 12 CL 90 fine to coarse siltstone and sandstone gravel.