Kevern, Richard (DH - CADW) - GOV.WALES · 2020. 3. 2. · piling contractor to test 7 no. piles minimum to 1.5 x swl. typical pile head detail. t.o.f. 75 600 1.h16 x 2m long reinforcement

From: Kevern, Richard (DH - CADW) Sent: 26 June 2013 14:03 To: David Cross

Subject: FW: Cyfarthfa Retail Park Development - Ref P/12/0219 - Planning Condition 12

David

Thank you for the consultation on Planning Condition 12 of the Decision Notice regarding P/12/0219 relating to mitigation of the impacts of construction on the SAM and on-site (undesignated)

archaeology.

The Slope Stability study produced by Clarkebond concludes that 'based on the slope stability assessments completed to date the development of the car park is not considered to have a detrimental effect on the slopes beneath the site or the ironworks' and recommends that the ground

conditions are inspected following excavation.

The Earthworks, Ground Improvement & Piling Vibration Assessment produced by Hammerson (Merthyr) Limited concludes that 'vibration monitors with notification (warning) and intervention systems are to be placed at 3 locations on the SAM boundary' and that 'monitoring should continue during the piling works to proposed notification (warning) and intervention thresholds of 4 - 10mm /s PPV for the retaining structures to the SAM'. These thresholds have been based on a number of

references, including English Heritage's guidance note on piling and archaeology.

Unfortunately Cadw does not have the structural engineering expertise to assess the validity of these reports, and must rely on the applicant 's assurances, and your authority, to ensure that this

mitigation is effective.

The SE edge of the scheme has been revised to 'pull the new boundary back by 2m' (in a limited area) and to allocate the parking spaces closest to the tunnel to motorcyles ('Extract From Powell Dobson's Car Park Layout). In Cadw's opinion the scheme could be improved further by the removal of the planned parking spaces immediately adjacent to the Scheduled Ancient Monument boundary on the SE side of the development site i.e the easternmost row of parking spaces, at least those south-eastwards from the proposed motorcycle parking . The scheme would thereby be enhanced by the provision of a 'cordon sanitaire' on either side of the heritage trail leading down to the viewing platform. This would give continuity with the proposed design for the NE edge of the

development.

Richard W Kevern Arweinydd Tîm Gwaith Achosion / Casework Team Leader Diogelu a Pholisi / Protection and Policy Amgylchedd Hanesyddol / Historic Environment Cadw Llywodraeth Cymru / Welsh Government

From: Cross, David [ Sent: 17 June 2013 10:57 To: Kevern, Richard (DH - CADW)

Subject: RE: Cyfarthfa Retail Park Development - Ref P/12/0219 - Planning Condition 12

Part 2 of 2

(Attachment 003-013 below)

David Cross Principal Planning Officer BSc (Planning), Ma (Urban Design), MRTPI

Merthyr Tydfil County Borough Council Unit 5, Triangle Business Park, Pentrebach, Merthyr Tydfil, CF48 4TQ

From: Cross, David

Sent: 17 June 2013 10:57 To: 'Richard.Kevern

Subject: Cyfarthfa Retail Park Development - Ref P/12/0219 - Planning Condition 12

Part 1 of 2

Good Morning Richard,

I have received details relating to the mitigation measures of the impacts of construction on the integrity of the nearby Schedule Ancient Monument (former Cyfarthfa Iron Works, GM 425). These details have been submitted pursuant to discharging condition 12 imposed on the above mentioned application. A copy of the decision notice has been attached for your reference.

Due to the number of plans/documents submitted I will forward the details across in two separate emails.

I would be grateful for your comments on the acceptability of these details and whether you are satisfied that condition 12 be discharged within 14 days from the date of this email. If you require any additional time or information please don’t hesitate to contact me.

Kind Regards

David Cross Principal Planning Officer BSc (Planning), Ma (Urban Design), MRTPI

Merthyr Tydfil County Borough Council Unit 5, Triangle Business Park, Pentrebach, Merthyr Tydfil, CF48 4TQ

From:

Sent: 07 June 2013 12:25

To: Cross, David Cc: ClaireMorison

Subject: Cyfarthfa Retail Park Extension - Planning Condition 12

David,

Please find attached our submission for the discharge of Planning Condition 12, impact of

construction on the Scheduled Ancient Monument.

Regards

Dietrich

----- Forwarded Message ----- From: Martin Hathaway < To: Sent: Thursday, 6 June 2013, 16:47 Subject: Merthyr Planning Condition 12

Dietrich,

Please find attached our response to Planning condition 12.

Much of the information has already been issued in connection with other planning

conditions but we have included all information as a complete response.

Regards

Martin

Martin Hathaway Director

For and on behalf of

clarkebond Registered in England & Wales No. 7775761

The information in this e-mail and any attachments is confidential and may be subject to legal professional privilege. It is intended solely for the attention and use of the named addressee(s).

If you are not the intended recipient, or person responsible for delivering this information to the intended recipient, please notify the sender immediately. Unless you are the intended recipient or his/her representative you are not authorised to, and must not, read, copy, distribute, use or retain this message or any part of it.

be green - keep it on the screen.

This e-mail and any files transmitted with it are confidential and intended

solely for the use of the individual or entity to whom they are addressed.

The contents of this e-mail represent the views of the individual(s) named

above and do not necessarily represent the views of Merthyr Tydfil County

Borough Council.

Mae'r e-bost hwn ac unrhyw ffeiliau a drosglwyddir gydag ef yn gyfrinachol

ac wedi'u bwriadu ar gyfer pwy bynnag y cyfeirir ef ato neu atynt. Mae

cynnwys yr e-bost hwn cynrychioli barn y sawl a enwir uchod, felly nid

ydyw'n dilyn ei fod yn cynrychioli barn Cyngor Bwrdeistref Sirol Merthyr

Tudful.

Cyngor Bwrdeistref Sirol Merthyr Tudful

Canolfan Dinesig

Stryd Y Castell

Merthyr Tudful

CF47 8AN

Merthyr Tydfil County Borough Council

Civic Centre

Castle Street

Merthyr Tydfil

CF47 8AN

clarkebond

UK Offices Bristol, Exeter, London

Overseas Office Abu Dhabi

Clarkebond (UK) Limited

Registered in England & Wales No 7775761

Registered Office : Inspiration Holdings Ltd, Empire Studio, 5-6 Leicester Square, London, WC2H 7NA

Certificate No. GB97/10493

THORN SITE Merthyr Tydfil

Slope Stability Overview 6th June 2013

Introduction

The site is located adjacent to the A470, approximately 2km West of Merthyr Tydfil, at National Grid Reference SO 037 067. Classified as Brownfield, the site was historically occupied by the Cyfarthfa Iron and Steel works (1765 – 1919) and more recently by Thorn Electrical Industries (1947 – 1993) for the manufacture of incandescent lamps.

Immediately to the East of the site there is a series of retaining walls, steep embankments approximately 7.0m in height and a tunnel. These features are all associated with the former Cyfarthfa Iron & Steelworks, protected by legislation as a Scheduled Ancient Monument (SAM GM425). The tunnel runs diagonally in from one of the retaining structures, the internal rear corner of which appears to coincide with the North-East boundary of the Thorn site. The tunnel is of substantial masonry construction with a brick arched roof and measures approximately 15m in length, x 4m wide and 4m high extending to 5m at the centre of the arch. Record drawings for the Thorn factory show the tunnel penetrating the then site boundary with the roadway to the rear of the factory passing over the top and therefore surcharging the structure.

Existing ground conditions

Existing ground conditions are typically 3m of clayey/sandy/gravelly Made Ground overlying Glacial Till which comprises predominantly sands and gravels. The ground water is at 8m depth.

Boundary sections

Additional topographic survey work was commissioned, in order to understand the current boundary conditions and assess the effects if any of the proposed development. Using this information we have generated a series of sections through the boundary as per our Drawings No. WB02534/107&108

Slope stability

Using the sections generated, we have also undertaken slope stability analysis at numerous points along the boundary (see separate report). All sections bar one pass the basic slope stability parameters with a factor of safety greater than 1.5. The exception being at the rearmost point of the tunnel where it coincides with boundary at chainage 53.2. This apparent instability is however due to limitations of the software which ignores the existence of the tunnel and the continuity of cover over the top and therefore highlights a potential a wedge failure. A combination of the profiles at chainages 45 and 53.2 are felt to be more realistic of the existing conditions and it is considered that the car park works proposed will not create a slope stability issue.

Page 2 of 2

clarkebond

Mitigation

In order to further mitigate the effects of the car park on the tunnel we have pulled the new boundary footpath back by 2m immediately adjacent to the tunnel and changed the use of the nearest parking bays to trolley bays and motorcycle spaces, as per the extract from Powell Dobson’s car park layout drawing.

Conclusion

The ground water is at depth and will not influence the slope stability. The Made Ground will be re-engineered and improved site wide, to include the Eastern boundary and approximate final compaction parameters have been used for the material properties in the slope analysis.

It can be demonstrated that increasing the surcharge load on the car parking has no significant effect on the slope stability and at these loadings, which are based on a larger articulated lorry being parked at the crest of the slope, there will be no detrimental effect on the slope below. Based on the slope stability assessments completed the development of the car park and internal access road is not considered to have a detrimental effect on the slopes beneath the site or the ironworks.

PILE NOTATION:Piles to be Driven Steel Tube, 250mm max Diameter with a S.W.L.of 250KN (unless noted on plan)Piles to have 900mm Min. Ctrs. within multi-pile Pile-Caps - (unlessnoted otherwise)Piles to have 75mm penetration into Pile-Caps.Piling Contractor to test 7 No. Piles minimum to 1.5 x SWL.

TYPICAL PILE HEAD DETAIL

T.O.F

75

600

1.H16 x 2m LONGREINFORCEMENTBAR TO BE SETCENTRALLY INTOCONCRETE PILE

2m-3

m

2m-3m DEPTH OFC35 CONCRETEFILLING INACCORDANCEWITH PILINGCONTRACTORSSPECIFICATION

450

PILE CAP

75mm PILEPENETRATIONINTO PILE CAP

PILE CUT OF LEVEL

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

A

B

C

D

E

F

G

H

1.1

1.1

E.1

D.1

C.1

7730 7730 6770 6770 6770 7250 7250 7250 7250 7250 7250 7250 7250 7250 7250 7250 2985

1700

1700

1301

013

010

1301

075

4754

63

7927

6395

3300

4097 3633 4367 3363 6155 8000 6155

450

450

450 450

450 450

450450

450 450

450 450

450

450

450

450

450 450

519

260

450

450

450 450

260

520

450 450

260

520

450 450

260

520

450 450

260

520

450 450

260

520

450

450

450

450

779

980

450 450

4480

900

780 450 450 450 450

450 450 450 450 450 450 450 450

519

260

1701 900

450

450 450 450

260

519

450 450

2985 900

5406

1751

3193

3158

1195

7210

450 450

5406

2054

4371

4337

4302

450 450

948

6563

6601

7637

1229

450 450

519

260

450

450

450

450

450

450 45

045

0

3312 6894 10207

356

450

450

450

450

1890

450

450

5267

Drawn Checked Sheet Size

RevisionDateScale

Project No. Discipline Drawing No.

Drawing Status

Drawing Title

Project

Client

clarkebondEngineering & Management Consultants

129 Cumberland Road,Bristol,BS1 6UY

tel +44 (0) 117 929 2244fax +44 (0) 117 929 3095email [email protected] www.clarkebond.com

Bristol Exeter London Abu Dhabi

@ T

his

dra

win

g m

ay n

ot be c

opie

d w

ithout prior

written p

erm

issio

n.

S

A1

DO NOT SCALE THIS DRAWING

CONTRACTOR TO CHECK ALL DIMENSIONS AND REPORTALL ERRORS AND OMISSIONS TO THE ENGINEER.

Release of electronic files for development by others.Clarkebond releases this file, which was used to producestructural and civil engineering layouts and details, on thefollowing conditions:

Future users of this file are responsible for theaccuracy and suitability of the original informationin the file for the application. Clarkebond will notrelease or advise of changes they make to theirelectronic files other than that required for the issueof their structural and civil engineering drawings forthe project.

CLARKE BOND WILL NOT BE RESPONSIBLE FOR:

Any information produces by a third party.The accuracy of the drawing file once modified byothers.

CDM RESIDUAL RISKSThe work shown on this drawing is both familiar to thedesigners and routinely safely built in similar circumstancesby competent contractors.Risks are not considered significant.Relevant data is included in the Pre-ConstructionInformation Pack.

Signed: Date:

AAs indicated

M:\C

B S

outh

West &

Wale

s\B

risto

l P

roje

cts

\WB

02534 -

Mert

hyr

Cyfa

rthfa

Reta

il P

ark

\Dra

win

gs\C

urr

ent\R

evit-R

13\B

&Q

\WB

02534-R

13-M

eth

yrT

ydfil-B

&Q

.rvt

Author Checker

WB02534 003

TENDER

PILE GA

Cyfarthfa Retail Park,Merthyr Tydfil,B&Q BuildingThorn Site

Hammerson Plc

01/04/13

Rev. Description By Date

A ISSUED FOR TENDER drb 06.02.13

020

3ELEVATION GRID

H

020

020

0201E

LEV

AT

ION

GR

ID18

2ELEVATION GRID

A,B,C

4E

LEV

AT

ION

ON

GR

ID 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

A

B

C

D

E

F

G

H

1.1

1.1

E.1

D.1

C.1

020

5

ELE

VA

TIO

N O

N

GR

ID 1.1

3022

5023

6023

7730 7730 6770 6770 6770 7250 7250 7250 7250 7250 7250 7250 7250 7250 7250 7250 2985

1700

1700

1301

013

010

1301

075

4754

63

3300

7730 7730 6155 8000 6155

7023

3010

GB03GB03 GB03

GB04 GB04 GB04 GB04 GB04 GB04 GB04GB04GB04GB04

GB

05G

B05

GB

05G

B05

GB

05G

B03

GB

03G

B03

GB

03G

B03

GB04 GB04 GB04 GB04 GB04 GB04 GB04 GB04 GB04GB04GB04GB04GB

03

GB03GB03GB03

GB

03

GB

02G

B02

GB

02G

B02

GB

02G

B02

GB

02

GB03GB03 GB03 GB03 GB03

GB

03G

B02

GB

02G

B02

GB

02G

B02

GB

02G

B08

GB

01G

B01

GB

01G

B01

GB

01G

B01

GB

07

GB

01

GB01 GB01 GB01

GB

01G

B01

GB

01G

B01

PC1PC2PC2

PC2PC2 PC2

PC3

PC2PC2PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2PC2

PC2PC2

PC2PC2

PC2PC3

PC3

PC2PC2PC2

PC2

PC2PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2PC2

PC2PC2

PC3

PC2

PC3

PC2

PC2

PC2

PC2

PC3

PC2

PC3

PC2

PC2

PC1PC1

PC1

PC2

PC2

PC3PC3

PC3PC3

PC3

PC3PC3

PC3 PC3PC4

PC2

PC2

PC2

PC2

PC2

PC2PC2

PC2PC2

PC2PC2

GB04

1022

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

GB

03

7552

2575

52

7553

450dp RCSprinklerTank

Base

450dp RCSprinklerTank

Base

7210

1301

013

010

1301

075

4754

63

PC2

GB

02

GB

02

GB03

GB

03GB03

GB

03

PUMP HOUSE BASE4650

3150

PC2

NOTE: COLUMNS ON GRID LINE 1 &1.1 TO BE DESIGNED FOR 10% OFCOLUMN Mp (FIRE BOUNDARYWALL CONDITION APPLICABLE)

14302

18.014675°

6389

3957

3957

4022

020

6ELEVATION GRID

G

020

7ELEVATION GRID

J

8023

GB01PC2

GB01 PC2

GB01GB01GB01GB01

GB

01

GB

01

GB

01

PC2PC3PC3PC3

PC1

GB04

PC1

GB

01

J

J

Q

Q

9023

4000

7781

4000

ALL STEELWORK TO BE GRADES355 UNLESS NOTEDOTHERWISE.

Foundations Notation.

1. All R.C. works cast on Ground to have 50mm Blinding Concreteunder, not over pile heads.2. All Concrete in Foundations to have Surface Protection layer toresist Sulphates.

.

TOP OFFOUNDATIONS

40

100mm MINCONCRETEENCASEMENTBELOW SSL

GRD FLR

TYPICAL H.D BOLT DETAIL

40mm DESIGN GAP UNDER BASE PLATE AND VOIDAROUND BOLTS TO BE SOLIDLY FILLED WITH A MIN 30N/mm² FINE CONCRETE GROUT COMPLETE WITH NON-SHRINK ADDITIVE

375 450 450 375

375 375

375

375

779

1529

1650

600

75

1650

600

75

1650

600

75

375

900

375

1650

1650

375 900 375

375 900 375

1650

375

375

750

750

375 375

375

375

600

75

750

4 PILE CAP (PC4) 3 PILE CAP (PC3) 2 PILE CAP (PC2) 1 PILE CAP (PC1)

ALLOW 140 kg/m³ FOR LOOSEBAR REINFORCEMENT IN RCELEMENTS


RevisionDateScale


Drawing Status

Drawing Title

Project

Client





@ T

his

dra

win

g m

ay n

ot be c

opie

d w

ithout prior

written p

erm

issio

n.

S

A1








Signed: Date:

BAs indicated

M:\C

B S

outh

West &

Wale

s\B

risto

l P

roje

cts

\WB

02534 -

Mert

hyr

Cyfa

rthfa

Reta

il P

ark

\Dra

win

gs\C

urr

ent\R

evit-R

13\B

&Q

\WB

02534-R

13-M

eth

yrT

ydfil-B

&Q

.rvt

Author Checker

WB02534 004

TENDER

FOUNDATION GA

Cyfarthfa Retail ParkExtension,Merthyr Tydfil,B&Q Building.

Hammerson Plc

01/25/13

Structural Foundation Schedule

Pile Ref PileType

PC1 1 Pile Cap - 750sq x 600mm RC

PC2 2 Pile Cap - 750x1650x600dp RC

PC3 3 Pile Cap - Ex1529x1650x600dp RC

PC4 4 Pile Cap - 1650sqx600dp RC

Structural Foundation Beams

Beam Ref Size

GB01 450 x 450dp RC Grd Beam









B ISSUED FOR TENDER drb 22.03.13

18

C

D

E

F

G

H

450

450

900

5406

1751

3193

3158

1195

7210

450 450

5406

2054

4371

4337

4302

450 450

948

6563

6601

7637

1229

5267 4930 5600 4692 4692

6000

6000

6000

6000

6000

5187

16301

9186

3858

450

450

450 450

0201E

ast

17

17

18

C

D

E

F

G

H

2985

GB04 GB04G

B05

GB

05G

B05

GB

05G

B05

GB

03G

B03

GB

03

GB

03

GB

03G

B03

GB01 GB01

GB

01

GB04 GB04

GB

01G

B01

GB

01G

B01

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC2

PC3

PC2

PC3

PC3

PC2

PC2

PC2

PC2

PC2

28di

a M

acal

loy

with

250

sq C

onc

Sur

roun

d

GB

03

PC2PC2

PC2PC2

PC2

GB01 GB01 GB01 GB01 GB01PC1

GB

01G

B01

GB

01G

B01

GB

01G

B02

GB01

PC2

PC2

PC2

PC2

PC2

PC2

GB01

GB01

GB01

GB01

GB01

GB

01

PC1

PC2

PC2

PC2

PC2

25180

3518

8

8035

9186

9321

7210 9091 8175

1301

013

010

1301

075

4754

63


RevisionDateScale


Drawing Status

Drawing Title

Project

Client





@ T

his

dra

win

g m

ay n

ot be c

opie

d w

ithout prior

written p

erm

issio

n.

S

A1








Signed: Date:

A 1 : 200

M:\C

B S

outh

West &

Wale

s\B

risto

l P

roje

cts

\WB

02534 -

Mert

hyr

Cyfa

rthfa

Reta

il P

ark

\Dra

win

gs\C

urr

ent\R

evit-R

13\B

&Q

\WB

02534-R

13-M

eth

yrT

ydfil-B

&Q

.rvt

Author Checker

WB02534 005

TENDER

GARDEN CENTREPILE & FOUNDATIONGA

Cyfarthfa Retail Park,Merthyr Tydfil,B&Q BuildingThorn Site

Hammerson Plc

01/30/13

1 : 200

PILE GA1 1 : 200

FOUNDATION GA2

Structural Foundation Beams

Beam Ref Size







Structural Foundation Schedule

Pile Ref PileType

PC1 1 Pile Cap - 750sq x 600mm

PC2 2 Pile Cap - 750x1650x600dp

PC3 3 Pile Cap - Ex1529x1650x600dp

PC4 4 Pile Cap - 1650sqx600dp



ridge

ridge

valley

FG

FG1500x1500

unobstructedlanding for lift

Up

13

11

12

9

6

8

7

4

5

10

14

020

3ELEVATION GRID

H

020

020

2ELEVATION GRID

A,B,C

4E

LEV

AT

ION

ON

GR

ID 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

A

B

C

D

E

F

G

7730 7730 6770 6770 6770 7250 7250 7250 7250 7250 7250 7250 7250 7250 7250 7250 2985

1700

1700

1301

013

010

1301

075

4754

63

2022

H

1.1

1.1

E.1

D.1

C.1

UB686x

254x

125

UB686x

254x

125

UC254x

254x

73

UB686x

254x

125

UB686x

254x

125

UC254x

254x

73

UB686x

254x

125

UB686x

254x

125

UC254x

254x

73

UB686x

254x

125

UB686x

254x

125

UC254x

254x

73

UB686x

254x

125

UB686x

254x

125

UC254x

254x

73

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

UB686x

254x

125

3300

7730 7730 6155 8000 6155

UB254x

146x

31

SHS 200

x200

x10

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31

UC254x

254x

73

UB254x

146x

31

UC254x

254x

73

UC254x

254x

73

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31 SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

UB254x

146x

31

UB254x

146x

31

UB254x

146x

31

UC254x

254x

73

UC254x

254x

73

UB254x

146x

31UC25

4x25

4x73

SHS 200

x200

x10

UC254x

254x

73

UC254x

254x

73

UC254x

254x

73

UB254x

146x

31

020

5

ELE

VA

TIO

N O

N

GR

ID 1.1

3022

5023

6023

7023

3010

1022

175mm THK RC GROUND BEARING SLAB REINFORCED WITH A252 FABRIC TOP

AND BOTTOM (30mm COVER, 3

00 min LAPS) O

N 1200g POLYTHENE GROUT

CHECK ON MINIM

UM 200mm OF WELL COMPACTED DOT TYPE 1 BACKFILL.

250m

m T

HK

RC

GR

OU

ND

BE

AR

ING

SLA

B R

EIN

FOR

CE

D W

ITH

A39

3 FA

BR

IC

TOP

AN

D B

OTT

OM

(30m

m C

OV

ER

, 400

min

LA

PS

) O

N 1

200g

PO

LYTH

EN

E G

RO

UT

CH

EC

K O

N M

INIM

UM

200

mm

OF

WE

LL C

OM

PA

CTE

D D

OT

TYP

E 1

BA

CK

FILL

.

250m

m T

HK

RC

GR

OU

ND

BE

AR

ING

SLA

B R

EIN

FOR

CE

D W

ITH

A39

3 FA

BR

IC

TOP

AN

D B

OTT

OM

(30m

m C

OV

ER

, 400

min

LA

PS

) O

N 1

200g

PO

LYTH

EN

E G

RO

UT

CH

EC

K O

N M

INIM

UM

200

mm

OF

WE

LL C

OM

PA

CTE

D D

OT

TYP

E 1

BA

CK

FILL

.

4022

020

6ELEVATION GRID

G

UC254x

254x

73

020

7ELEVATION GRID

J

UB686x

254x

125

UB686x

254x

125

UC254x

254x

73

UC254x

254x

73

UC254x

254x

73

SHS 200

x200

x10

SHS 200

x200

x10

UC254x

254x

73

UC254x

254x

73

UC254x

254x

73

UC254x

254x

73

UC152x

152x

30

UC254x

254x

73

UC254x

254x

73

UC254x

254x

73

RHS300x

200x

8.0

RHS300x

200x

8.0

UC254x

254x

73

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

SHS 200

x200

x10

PFC200x

75x2

3

PFC200x

75x2

3

8023

SHS 200

x200

x10

SHS 200

x200

x10

PFC200x

75x2

3

PFC200x

75x2

3

J

J

Q

Q

9023

175mm THK RC GROUND BEARING SLABREINFORCED WITH A252 FABRIC TOP ANDBOTTOM (30mm COVER, 300 min LAPS) ON 1200gPOLYTHENE GROUT CHECK ON MINIMUM 200mmOF WELL COMPACTED DOT TYPE 1 BACKFILL.

UC152x

152x

30

UC152x

152x

30UC15

2x15

2x30

UC152x

152x

30

UC152x

152x

30

UC254x

254x

73

UC254x

254x

73

PFC200x

75x2

3

PFC200x

75x2

3

PFC200x

75x2

3

NOTE:UNIT 1 (175THK) SLAB TO COMPLY WITH THEREQUIREMENTS OF THE B&Q 2012 SHELL SPECIFICATION


RevisionDateScale


Drawing Status

Drawing Title

Project

Client





@ T

his

dra

win

g m

ay n

ot be c

opie

d w

ithout prior

written p

erm

issio

n.

S

A1








Signed: Date:

B 1 : 200

M:\C

B S

outh

West &

Wale

s\B

risto

l P

roje

cts

\WB

02534 -

Mert

hyr

Cyfa

rthfa

Reta

il P

ark

\Dra

win

gs\C

urr

ent\R

evit-R

13\B

&Q

\WB

02534-R

13-M

eth

yrT

ydfil-B

&Q

.rvt

Author Checker

WB02534 006

TENDER

GROUND FLOOR GA

Cyfarthfa Retail ParkExtension,Merthyr Tydfil,B&Q Building.

Hammerson Plc

01/02/13



B ISSUED FOR TENDER drb 22.03.13

Engineering & Management Consultants

clarkebond


129 Cumberland RoadBristolBS1 6UY

tel +44 (0) 117 929 2244fax +44 (0) 117 929 3095e-mail [email protected] www.clarkebond.com

Report No Date

WB02534 February 2013

Project

Thorn Site, Merthyr Tydfil. Earthworks, Ground Improvement & Piling Vibration Assessment

Client

Hammerson (Merthyr) Limited

CLARKEBOND (UK) LTD 129 CUMBERLAND ROAD BRISTOL BS1 6UY

Report No: Date:

WB02534 February 2013

Project:

Thorn Site, Merthyr Tydfil Earthworks, Ground Improvement & Piling Vibration

Assessment

Issue Number Status Description of Amendments

Rev A Final Dynamic Compaction Omitted 01 May ‘13

Report prepared by:

Signed

Engineer PJ Edbrooke

Approved for issue by:

Signed

Director M G Hathaway

This report is provided for the benefit only of the party to whom it is addressed. Clarke Bond does not extend responsibility to any third party for the whole or any part of the contents. Clarke Bond owes no duty of care in relation to this report to any third party. The reportage has been undertaken with all reasonable skill, care and due diligence. Clarke Bond disclaims any responsibility to the client or others in respect of any matter(s) outside this agreed scope of the above works.

© Clarkebond (UK) Ltd

WB02534 Thorn Site, Merthyr Tydfil Earthworks, Ground Improvement & Piling Vibration Assessment February 2013

Thorn Site, Merthyr TydfilEarthworks, Ground Improvement & Piling Vibration Assessment

1.0 The site

The site is located adjacent to the A470, approximately 2km West of Merthyr Tydfil, at National Grid Reference SO 037 067. Classified as Brownfield, the site was historically occupied by the Cyfarthfa Iron and Steel works (1765 – 1919) and more recently by Thorn Electrical Industries (1947 – 1993) for the manufacture ofincandescent lamps.Immediately to the East of the site there is a series of retaining walls and steep embankmentsapproximately 7.0m in height. An old blocked-off tunnel runs some 15m from one of these retainingstructures towards the North-East boundary of the site. These walls and embankments are allassociated with the former Cyfarthfa Iron & Steelworks and are protected by legislation as aScheduled Ancient Monument (SAM GM425). The wider area including the site itself is included in anarea classified as a conservation area and HLC - Historic Land Characterisation area.Several utilities with associated easements run around the perimeter of the site on the South-Westerncorner, services include Gas, Electricity, BT and several large diameter (600, 700, & 150) StrategicWater mains (Welsh Water). A public footpath runs along the Southern and Eastern boundary to anunderpass running beneath the A470, a pedestrian route continues up the remainder of the Easternboundary and across the adjacent land.

The site is underlain by Glacial deposits overlying Coal measures at depth. Made ground typically consisting of black sand, coarse gravel with ash, coal traces, demolition rubble and boulders is present across the site, varying in depth from approximately 3.00m – 7.50m, see Site Investigation reports. Some buried archaeological remains of the Iron and Steel works were discovered in a recent archaeological investigation, whilst more modern obstructions thought to be associated with the foundations and ground slabs of the Thorn factory were encountered during the ground investigations, the latter being found approximately 1.0m below EGL. Underground streams or culverts (associated with previous developments) leading to the low level stream North of the site may be present, where encountered they will be diverted as necessary prior to being abandoned. Due the depth and nature of the made ground, a ground preparation or enabling works contract is proposed, prior to construction of the main development.

The enabling works will be subject to an archaeological watching brief.

2.0 Engineering considerations

The made ground is not suitable as a founding stratum, due to its inherent variability and risk of intolerable settlement. Conventional shallow strip and pad foundations will not be acceptable and therefore alternative founding and ground improvement techniques must be considered.

Foundations: Due to the depth and number of obstructions and the need to penetrate the glacial till, small diameter (approx’ 180) thick-wall open steel tube piling is deemed the most appropriate. These are classified as small displacement piles and will be driven in discreet locations coincident with the main building grid with insitu concrete ground beams spanning between insitu concrete pile caps. The open nature of the tube facilitates chiselling through obstructions in the made ground and penetration into the glacial deposits. Pile lengths in the order of 10m are envisaged.


Ground Slabs: In order minimise pile numbers and allow the use of ground bearing slabs, several ground improvement techniques have been reviewed in order to limit the overall settlement to acceptable limits. Rolling Dynamic Compaction, Vibro Compaction and Dynamic Compaction were discounted as being unsuitable for this site due the close proximity with the SAM and services corridor, thus we selected Traditional Excavation and re-compaction in layers for use under the building footprint, service yards, hardstandings and car parks.

3.0 Vibration:

The potential for vibration was considered at an early stage in the design process, and the building structures were sighted as far away from the SAM boundary as possible. The minimum distance being approx’ 25m to the North of the site, increasing to over 90m in the South.

As a requirement of conditions imposed under Planning, the potential effects of vibration during the Earthworks, Ground Improvement & Piling processes needs to be considered. This requirement relates to the standing structures of Scheduled Ancient Monument 425 (Cyfarthfa Iron & Steelworks) on the Eastern boundary. We have however also considered the statutory services corridor on the Southern and Western boundary (water, gas, electricity and BT)

4.0 Earthworks, Ground Improvement & Piling proposals and mitigation measures:

The Earthworks, Ground Improvement & Piling proposal are defined in our document ‘Thorn Site Overview and Schedule of Works and our drawings No. WB02534/S/001 & 002 the method statement on these drawings being superseded the document noted above. The piles will be installed crawler mounted rig fitted with a hydraulic impact hammer, full details will be included in the specialist contractor’s method statement. The selection of the pile/rig type is itself a mitigation measure, as this represents the least intrusive method of piling available, to contend with the demolition rubble, boulders, sub-structure masonry and underlying glacial deposits. As a further mitigation measure, all pile positions are to be probed to a depth of 2.5m, any obstructions removed and the excavation re-filled with granular material. Chiselling through the deeper below-ground obstructions was considered the most suitable method of dealing with obstructions.

The induced transient vibration levels associated with this type piling system are shown to be low, as can be seen from test data contained under Annexe D of BS 5228-2:2009. Open ended driven cast in place piles in similar ground conditions show average ppv’s of 3.5mm/s at 20m.

The ground improvement technique utilises traditional plant and equipment.

5.0 Vibration limits

The following references were considered in arriving at an appropriate transient vibration limits: i) BS 5228-2:2009 Code of practice for noise and vibration control on construction and open sites

– Part 2: Vibration.ii) English Heritage Piling and Archaeology – Guidance Noteiii) Arcellor Mittal Piling Handbook 8th Ed (2008)iv) Eurocode 3 Part 5 Pilingv) BRE Digest 403 19In summary, the guidance provided in these documents is as follows:Table B.2 BS 5228-2:2009 suggests the following limits (Peak Particle Velocity in mm/s)Reinforced or framed structures Industrial and heavy commercial buildings50 mm/s at 4 to 15 Hz50 mm/s at 15 Hz and above


Unreinforced or light framed structures Residential or light commercial buildings 15 mm/s at 4 Hz increasing to 20 mm/s at 15 Hz. 20 mm/s at 15 Hz increasing to 50 mm/s at 40 Hz and above.

Tabulated permissible limits for classes of structure l Ruins and damaged buildings, protected as monuments 2 mm/sll Buildings with visible defects, cracks in masonry 4 mm/slll Undamaged buildings in technically good condition 8 mm/slV Well-stiffened buildings (i.e industrial) 10-40mm/s

Notwithstanding the above, BS5228 also recommends limiting ppv’s in masonry retaining walls to 10mm/s at the base and 40mm/s at the crest. With vibrations limits on buried services of 15mm/s continuous and 30mm/s intermittent.

Table 12.3.6.2 Arcellor Mittal Handbook reproduced from Eurocode3: Part 5. l Ruins, buildings of architectural merit, continuous 2 mm/s, transient 4mm/sll Residential, continuous 5 mm/s, transient 10mm/slll Light Commercial, continuous 10 mm/s, transient 20mm/slV Heavy Industrial, continuous 15 mm/s, transient 30mm/sV Buried Services, continuous 25 mm/s, transient 40mm/s

As can be seen, there is considerable variation in the permissible values between these references.

The retaining structures are in effect ruins which may be cracked and distorted but protected as a Scheduled Ancient Monument, and closely aligned to class l buildings as defined in the English Heritage guidance.

BS 5228-2:2009 B.3.2 states “Important buildings which are difficult to repair might require special consideration on a case by case basis. A building of historical value should not (unless it is structurally unsound) be assumed to be more sensitive.”

Eurocode 3: part 5 also states that the values prescribed for continuous vibration may be doubled in respect of transient vibration. As both the ground improvement and piling operations are of a temporarily sustained source of mechanical vibration, they can therefore defined as transient.

6.0 Conclusion:

Vibration monitors with notification (warning) and intervention systems are to be placed at 3 locations on the SAM boundary and 2 locations adjacent the services corridor.

On-site measurement and monitoring of vibration levels is to be undertaken during the conventional earthworks to the external areas, to establish background working levels. The conventional earthworks will consist of site stripping, screening, removal of obstructions, crushing of site won material which is to be replaced and compacted in layers in accordance with the Specification for Highways Works.

Monitoring should continue during the Piling works to proposed notification (warning) and intervention thresholds of 4 -10mm/s PPV for the retaining structures to the SAM and 30-40mm/s PPV for buried services

Documents

Kevern, Richard (DH - CADW) - GOV.WALES · 2020. 3. 2. · piling contractor to test 7 no. piles minimum to 1.5 x swl. typical pile head detail. t.o.f. 75 600 1.h16 x 2m long reinforcement