Feasibility Report - Wirral CouncilFINAL-REV-1).pdf · Feasibility Report Saughall Massie Link Road – Feasibility Study Doc Ref: CO00205379/DOC/FR Rev 1 September 2016

Feasibility Report

Saughall Massie Link Road –

Feasibility Study

Doc Ref: CO00205379/DOC/FR Rev 1

September 2016

Document Control Sheet

Project Name: Saughall Massie Link Road – Feasibility Study

Project Number: CO00205379

Report Title: Feasibility Report

Report Number: CO00205379/DOC/FR

Issue

Status/Amendment

Prepared Reviewed Approved

DRAFT

Name: Scott Hunter

Name: Geoff Rydill

Name: Geoff Rydill

Signature:

Date: 22.09.16

Signature:

Date: 23.09.16

Signature:

Date: 23.09.16

FINAL

Rev 1

Name: Scott Hunter

Name:

Name:

Signature:

Date: 20.10.16

Signature:

Date: 20.10.16

Signature:

Date: 20.10.16

Project Name Saughall Massie Link Road – Feasibility Study

Document Title Feasibility Report

Doc. Ref.:CO00205379 /CO00205379/DOC/FR Rev. 1 - i - Issued: September 2016

Contents

1 Executive Summary ............................................................................................ 1

2 Introduction ....................................................................................................... 7

Commission Details ............................................................................................ 7 2.1

Golf Resort Development Proposals ..................................................................... 7 2.2

Scheme Identification ........................................................................................ 8 2.3

Report Structure ................................................................................................ 9 2.4

3 Existing Site Conditions ................................................................................... 10

Location and Highway Context .......................................................................... 10 3.1

Site Description and Key Features ..................................................................... 12 3.2

Topography .................................................................................................... 13 3.3

Ground Conditions ........................................................................................... 13 3.4

Environmental Conditions ................................................................................. 22 3.5

Existing Services .............................................................................................. 22 3.6

4 Site Surveying and Investigation ..................................................................... 23

Topographical Survey ...................................................................................... 23 4.1

Geotechnical Site Investigation ......................................................................... 23 4.2

5 Scheme A: Saughall Massie Link Road ............................................................. 24

Option Identification ........................................................................................ 24 5.1

Link Geometry – Horizontal Alignment ............................................................... 24 5.2

Link Geometry – Vertical Alignment ................................................................... 25 5.3

Structures at Watercourse Crossings ................................................................. 26 5.4

Land Requirements .......................................................................................... 30 5.5

Statutory Undertakers ...................................................................................... 30 5.6

Highway Cross Section and Crossfall ................................................................. 32 5.7

Geotechnical Sub-Grade Assessment ................................................................. 32 5.8

Road & Footpath / Cycleway Construction ......................................................... 38 5.9

Surface Water Drainage ................................................................................... 39 5.10

Junction Design Geometry ................................................................................ 40 5.11

Junction Design Capacity Analysis ..................................................................... 41 5.12

Street Lighting ................................................................................................ 46 5.13



Doc. Ref.:CO00205379 /CO00205379/DOC/FR Rev. 1 - ii - Issued: September 2016

6 Scheme B: Improvements to Saughall Massie Road ........................................ 47

Existing Link Geometry & Option Identification ................................................... 47 6.1

Historical Accident Analysis ............................................................................... 48 6.2

Proposed Link Geometry .................................................................................. 48 6.3

Land Requirements .......................................................................................... 49 6.4

Statutory Undertakers ...................................................................................... 50 6.5

Highway Cross Section and Crossfall ................................................................. 52 6.6

Geotechnical Subgrade Assessment and Road & Footpath / Cycleway 6.7

Construction ................................................................................................... 52

Surface Water Drainage ................................................................................... 55 6.8

Street Lighting ................................................................................................ 55 6.9

7 Scheme C: Improvements to Heron Road ........................................................ 57

Technical Review of Design Proposal & DMRB Compliance .................................. 57 7.1

8 Cost Estimates.................................................................................................. 60

Scheme A ....................................................................................................... 60 8.1

Scheme B ....................................................................................................... 61 8.2

Scheme C ....................................................................................................... 62 8.3

9 Conclusions and Recommendations ................................................................. 63

10 Appendices ....................................................................................................... 66

Appendix A – Existing Site Conditions

A.1 – Site Location

A.2 – Environmental Conditions

Appendix B – Site Surveying and Investigations

B.1 – Topographical Survey

B.2 – Geotechnical Site Investigation



Doc. Ref.:CO00205379 /CO00205379/DOC/FR Rev. 1 - iii - Issued: September 2016

Appendix C – Scheme A: Saughall Massie Link Road

C.1 – Option Identification

C.2 – Link Geometry (Horizontal & Vertical Alignment)

C.3 – Structures at Watercourse Crossings

C.4 – Highway Cross-Section

C.5 – Statutory Undertakes (C2 Consultation)

C.6 – Statutory Undertakes (C3 Consultation)

C.7 – Road Construction & Surface Water Drainage

C.8 – Junction Design Geometry

C.9 - Junction Design Capacity Analysis

C.10 – Street Lighting

C.11 – Cost Estimate

Appendix D – Scheme B: Improvements to Saughall Massie Road

D.1 – Existing Link Geometry & Option Identification

D.2 – Historical Accident Analysis

D.3 – Proposed Link Geometry & Land Acquisition

D.4 – Highway Cross-Section

D.5 – Statutory Undertakes (C2 Consultation)

D.6 – Statutory Undertakes (C3 Consultation)

D.7 – Road Construction

D.8 – Street Lighting

D.9 – Cost Estimate

Appendix E – Scheme C: Improvements to Existing Heron Road

E.1 – Existing Design Proposal

E.2 – Cost Estimate

Appendix F – Risk Register & CDM

F.1 – Risk Register & Designer Hazard Management Plan



Doc. Ref.:CO00205379 /CO00205379/DOC/FR Rev. 1 - 1 - September 2016

1 Executive Summary

1. Amey Consulting has been appointed to develop proposals for the Proposed

Saughall Massie Link Road and related highway infrastructure. This Feasibility

Study focuses on a package of road improvement schemes, identified to support

the development of the Hoylake Golf Resort Development and ensure excellent

linkages to the local and regional road networks.

2. In July 2015 Wirral Council approved the appointment of the Nicklaus Joint

Venture Group as the Council’s preferred development partner. Initial proposals

are presented in the layout below.

3. This study considers a package of three road improvement schemes, referred to

as Schemes A.B and C. Scheme A is a new road, Saughall Massie Link Road,

which passes through the Golf Resort Site. Scheme B is the Upgrade of Saughall

Massie Road. Scheme C is the Upgrade of Heron Road.




4. The scope of feasibility work undertaken includes site assessment, surveying and

ground investigations, highway and structural design, junction assessments and

cost estimating.

5. Key findings from the site assessment are:

The site is situated in a rural, agricultural land use area with generally ‘flat’

topography, and is low lying in the central area of the Golf Resort, with a history

of flooding and drainage issues.

Saughall Massie Road is currently a narrow and twisty road, lacking footpath

facilities, with poor visibility and a poor accident record.

A number of watercourses are present within the site area, including the primary

rivers Newton Brook and The Birket.

The site is underlain with sandstone bedrock and superficial geology

predominately recorded as Glacial Till - clay, sandy, gravelly and cobbly material




with tidal flat deposits comprising soft silty clay and layers of sand, gravel and

peat.

Intrusive ground investigation was carried to provide further details on the

ground conditions prevailing in the vicinity of the new link road. This indicates

that the ground is highly compressible in significant areas of the site.

6. Two alignment options are considered for Scheme A. Both aim to closely

complement the layout of the Golf Course development, whilst complying with

recognised geometric highway design criteria set out in the Design Manual for

Roads and Bridges (DMRB). Option 1 is preferred because it fits within

understood land ownership boundaries, and has been developed in greater

detail. Option 2 is for the most part similar, but includes a different alignment at

the southern link with Saughall Massie Road. Option 2 offers benefits in terms

of junction alignment and bridge design but would require land acquisition.

7. Key findings arising from the feasibility design undertaken for Scheme A are:

Both options provide alignment geometry that is consistent with DMRB TD 9/93

for a design speed of 60kph.

Both options include a bridge crossing The Birket and a total of 10 culvert

crossing of minor watercourses. The latter requirement may be tempered by the

findings of site wide environmental and flood risk assessments, and the wider

Golf Course site development proposals.

Option 1 includes an arrangement of two bridges that carry a roundabout

junction arrangement over Newton Brook at the intersection of the link road and

Saughall Massie Road. Although complex, this is considered to be the least

expensive solution. Alternative solutions involving the realignment of a section

of the Brook Have also been considered through initial discussion with the

Environment Agency. The junction is located in a different position in Option 2,

lessening the impact of the Brook.




Ground improvement measures are likely to be required to limit settlement of

the new road in some sections. It is envisaged that a combination of ‘cut and

fill’ and pre-construction’ surcharging may provide a suitable solution where

there is a desire to minimise excavation and dewatering. Opportunities to co-

ordinate the ground works with those of the Golf Course development may offer

significant benefits.

It is likely that the highway drainage system will incorporate appropriate

sustainable drainage solutions (SuDS) that will, where possible, include at source

storm storage and ground infiltration facilities. It may be possible to utilise

features within the adjacent development site to achieve an optimised solution.

2 roundabout junctions are included within the design; at the intersection with

Saughall Massie Road and at a mid point along the link to provide access to key

development attractions. These are consistent with the design guidance

provided in DMRB TD16/07 and are capable of accommodating the swept paths

of large design vehicles. The traffic capacity provided by the junctions has been

assessed through application of traffic flows considered appropriate in lieu of a

more detailed traffic assessment.

8. Appraisal of Saughall Massie Road confirms that sections of the road do not

conform to design curvature and visibility criteria. Realignment and assessment

of land requirements proposed to determine an improvement scheme that

conforms to DMRB design guidance.

9. Key findings arising from the feasibility design undertaken for Scheme B are:

The proposed arrangement provides a footpath and cycle facility on the southern

side of the road, which ties in to facilities to the east and best suits an initial

assessment of impacts on existing underground services.

The proposed arrangement addresses the root cause of many accidents

recorded on the road by addressing existing geometry and visibility problems.




The proposals will require significant land acquisition, mostly from within

adjacent agricultural farm plots.

Some residential land acquisition is required to provide continuous footpath and

cycle facilities.

10. The report provides a technical review of an existing design for improvements to

Heron Road. This was carried out with reference to relevant DMRB guidance

and indicates that the proposals are largely compliant, whilst highlighting some

specific areas where more work and / or some modest departures may be

required to achieve an approved scheme.

11. The study includes the provision of detailed cost estimates, based upon the

engineering design work undertaken. The estimates also include the diversion

costs arising from C3 consultation with affected utilities and application of

optimism bias in accordance with Green Book Accounting principles:

Scheme A - £7.9m

Scheme B - £5.9m

Scheme C - £2.8m

12. Key conclusions and recommendations arising from the study are:

The options presented for Schemes A and B complement the Golf Course

Development proposals and also offer wider strategic benefits to the highway

network.

Significant ground improvement work is likely to be necessary to construct

Scheme A. Initial assessment suggests surcharging may be a cost effective and

sustainable approach. Given the time required to consolidate the ground and

the need for temporary loading material, opportunities to co-ordinate this work

with that of the Golf Course Development may provide significant benefits and

should be explored as the design are progressed.




The intersection of the preferred alignment and the existing Saughall Massie

Road coincides with a meandering section of Newton Brook. The Environment

Agency has expressed their preference, if possible, for either the junction to be

relocated or the watercourse diverted. They acknowledge that both of these

options may not be possible due to land ownership issues and, if this remains

the case, would prefer a scheme that maintained an open river within the

roundabout.

Option 2 locates the junction to the east, removing the need to cross Newton

Brook at Saughall Massie Road. It is also noted that, the implementation of

Scheme B would result in a relocated junction position that would address some

of the complexities associated with the current proposal. These options and

variations may be the subject of further consideration during later stages of

development.

The development provides an ideal opportunity for Sustainable Drainage

Systems (SuDS) with options for features such as retention ponds, reedbeds,

swales and porous pavements. It is anticipated that the design of the Golf

Course Development will be guided by the findings of Flood Risk and

Environmental Impact Assessments and, that the drainage, earthworks,

topography and waste management strategies adopted across the site will also

be applicable to the Link Road.

Wirral Council have submitted proposals to the Liverpool City Region Transport

Advisory Group and intend to prepare and submit Major Scheme Business Cases

for Schemes A and B, for funding approval. This feasibility study provides

developed technical proposals and detailed cost estimates that are a suitable and

robust basis for informing the commission and progression of Major Scheme

Business Cases for Schemes A and B.




2 Introduction

Commission Details 2.1

Amey Consulting has been appointed by Wirral Borough Council to undertake a 2.1.1

feasibility study relating to provision of the Proposed Saughall Massie Link Road

and related highway infrastructure. The study focuses on a package of road

improvement schemes, identified by Wirral to support the development of the

Hoylake Golf Resort Development and ensure excellent linkages to the local and

regional road networks.

The scope of work presented in this report relates to details provided in 2.1.2

Consultant Brief prepared by Wirral BC, details provided in Amey’s submission

and Project Initiation documents and the outcomes of discussions during

progress meetings.

Golf Resort Development Proposals 2.2

Developing a world class international golf resort in Hoylake has been a long-2.2.1

term aspiration of Wirral Council and inclusion of the project in a range of

Council strategic policy documents illustrates its importance as a driver for

regeneration and economic development in Wirral.

Wirral Council commissioned a number of studies between 2004 and 2007 to 2.2.2

shape the project which concluded that the project provided an excellent

opportunity to deliver and sustain a unique golf based resort offer that could

build upon England’s Golf Course Brand and address regional demand for a high

quality associated hotel.

In July 2015 Wirral Council approved the appointment of the Nicklaus Joint 2.2.3

Venture Group as the Council’s preferred development partner. The Council has

recently conducted a number of consultation events to provide local residents

with an update and opportunity to comment on the project.




Initial proposals are presented in the layout shown overleaf. These proposals 2.2.4

include an indicative link road position that complements the layout and provides

access to key features and destinations within the development. The routing of

this road and its context in relation to the development as a whole is a key

factor influencing the link road alignment design and routing proposals

considered in this Feasibility Study.

Scheme Identification 2.3

The study considers a package of three road improvement schemes, referred to 2.3.1

as Schemes A.B and C.

Scheme A is a new road scheme entitled Saughall Massie Link Road. The 2.3.2

Hoylake Golf Resort Masterplan includes a new road that will pass through the

site. The route indicated in the Masterplan and developed in an initial alignment

prepared by the Client, together identify the routing priorities for the new road

and establish its context within the layout of the wider development and

boundaries of available land.




Scheme B is the Upgrade of Saughall Massie Road. A section of Saughall Massie 2.3.3

Road have been upgraded to meet current design standards. The study

assesses the feasibility of upgrading the remaining section, between Three Lanes

End and Gilroy Road, to a similar standard.

Scheme C is the Upgrade of Heron Road. A developed scheme proposal was 2.3.4

prepared by Wirral some time ago but is yet to be implemented. The study

includes the technical review of existing design proposals and the development

of a cost estimate for their implementation.

Report Structure 2.4

The remaining sections of the report are structured to meet the requirements of 2.4.1

the brief and provide an easy to follow, concise overview of the work

undertaken, output and conclusions drawn.

Section 3 and 4 provide an overview of the site including information obtained 2.4.2

through desk study, searches and complementary site survey and investigation

work implemented specifically to inform this study.

Sections 5 and 6 provide summaries of the design activities undertaken in 2.4.3

support of Schemes A and B.

Section 7 summarises the design review of Scheme C. 2.4.4

Section 8 provides a summary of the cost estimating carried out for all three 2.4.5

schemes.

Supporting information is provided in a series of separately bound Appendices. 2.4.6




3 Existing Site Conditions

Location and Highway Context 3.1

The proposed Hoylake Golf Resort site is located South East of Hoylake town 3.1.1

centre, North East of West Kirby and West of Upton.

The proposed new link road is to provide access from the A540 Meols Drive / 3.1.2

A553 Market Street to Saughall Massie Road. The existing land is used primarily

for agricultural farming, with Hoylake Municipal Golf Course located adjacent

(North West) of the proposed alignment.

The section of the B5192 Saughall Massie Road considered for improvement 3.1.3

runs East to West from Three Lanes End Roundabout (Heron Road - North,

Pump Lane - South and Saughall Massie Road - East) to the T Junction at B5139

Frankby Hill. It is approximately 2.3km in length and operates as a single lane

carriageway in both directions.

This section of Saughall Massie Road is narrow, twisty and offers poor / 3.1.4

restricted driver visibility in both carriageway directions, with a typical example

of driver visibility conditions shown as follows:




The existing carriageway width varies significantly, with the widest measured at 3.1.5

chainage 640m as 6.90m and the narrowest measured between chainages 1900

to 2100m as ranging between 4.980 to 5.160m.

The use of vehicle overtaking is permitted, however by inspection it is 3.1.6

considered dangerous for road users to attempt to overtake due to restricted

advanced visibility, with multiple blind bends present in both directions of travel.

The provision of a pedestrian / cycle facility is not formally provided on either 3.1.7

side of the carriageway, with members of the public / cyclists forced to position

themselves as close as possible to the adjacent hedge rows / agricultural

fencing.

Refer to DWG: CO00205379_F_SchB_001 (Appendix D.1) for existing alignment 3.1.8

appraisal and Appendix D.2 for historical traffic accident data.

Heron Road is an unclassified road running north to south, joining the B1592 3.1.9

Saughall Massie Road to the A533 Birkenhead Road. The road is approximately

1.7km in length and is similar in nature to the section of B1592 Saughall Massie

Road considered.




The existing alignment is meandering, with physical constraints including sub-3.1.10

standard horizontal radii and restricted visibility due to adjacent hedgerows and

field vegetation. A typical example of driver visibility conditions is shown below:

Site Description and Key Features 3.2

The following watercourses have been identified to cross the proposed highway 3.2.1

alignment, from review of existing Environmental Agency river network maps

and the topographical survey undertaken:

Primary River: 3 No.

Secondary River: 0 No.

Tertiary River: 1 No.

Land Drain: 8 No.

Culverts: 1 No.

A high voltage overhead power grid distribution line crosses the site, running 3.2.2

from north to south. It is understood that diversion of this infrastructure may

form part of the works proposed for the wider golf resort development.

Additional key features identified which are to be considered in the proposed link 3.2.3

road design include the Liverpool to West Kirby railway line and level crossing at

Hoylake Station and the existing masonry arch bridge and crossing of Newton

Brook on Saughall Massie Road.




Topography 3.3

The topography of the site on which the Hoylake Golf Resort Masterplan is to be 3.3.1

situated is generally flat and, notably is low lying in the central area where the

site has been shown to have a history of flooding and drainage related issues.

Ground Conditions 3.4

Published Geology

The British Geological Survey (BGS) 1:50,000 maps were reviewed to determine 3.4.1

the drift and solid geology of the scheme area.

Bedrock within the site boundary is recorded to comprise various Triassic rock 3.4.2

formations including: Delamere Sandstone Formation, Fordsham Sandstone

Member, Tarporley Siltstone Formation and the Sidmouth Mudstone Formation.

The superficial geology overlying the bedrock is predominately recorded as 3.4.3

Glacial Till - clay, sandy, gravelly and cobbly material with tidal flat deposits

comprising soft silty clay and layers of sand, gravel and peat, recorded along the

western extents of the study area. Wind-blown sand deposits are located further

west along the coastline of Hoylake and West Kirby.

Made Ground materials are anticipated to be present in proximity of existing 3.4.4

road infrastructure and areas subject to current and historic development.

Hydrogeology / Hydrology

Information obtained from the Environmental Agency (EA) records part of the 3.4.5

site as a designated Zone 3 groundwater source protection zone. The superficial

deposits are recorded as a Secondary A aquifer (west portion of study area) and

Secondary (undifferentiated) (east potion of study area). Bedrock underneath

the site is indicated to be predominantly Secondary B, with some of the site also

within a principal aquifer zone.




The groundwater vulnerability of the New Link Road Site is recorded as major 3.4.6

aquifer – High. The groundwater vulnerability of the Saughall Massie Road and

the Heron Road is recorded as major aquifer- intermediate

The EA website indicates that part of the New Link Road route has a low ranging 3.4.7

to high risk of flooding from rivers.

Mining/Quarrying

The Coal Authority’s interactive map of the scheme shows a large coal mining 3.4.8

reporting area to be located off the western coast beyond Hoylake,

approximately 2km from the site. The BGS GeoIndex map shows deep coal to

underlie the site, at significant depth and beyond the scheme’s zone of influence

and therefore unlikely to affect the proposed works.

Ground Investigation information

In August 2016 an intrusive soil investigation was undertaken along areas of the 3.4.9

proposed Scheme A to supplement the available desk study data, further

investigate existing ground conditions and facilitate the feasibility assessment of

the highway proposals. This investigation comprised of four trial pit excavations

and dynamic cone probing with associated soils logging and sampling for

classification purposes.

The four trial pits (TP07, TP06, TP05 and TP04) were completed to a maximum 3.4.10

of 3.2 m depth performed in the vicinity of the proposed Ch20, Ch280, Ch720

and Ch870, respectively. At each trial pit a dynamic cone penetration test was

undertaken and count blow results were correlated with California Bearing Ratio

(CBR) values based on figure 4 of TRL report (TRL587).

In addition to the recent ground investigation data, historic BGS borehole 3.4.11

information has been obtained and reviewed to facilitate the ground condition

assessment for Schemes A, B and C. A total of eleven BGS boreholes, deemed

relevant to the schemes were available for review.




Table 3.1 and 3.2 present a summary of ground conditions and indicative CBR 3.4.12

values based on the available ground investigation data. The 2016 Factual

Ground Investigation Report and historic BGS borehole information are

presented in Appendix B.2.

Table 3.1: Scheme A - Ground Conditions and CBR Summary

Chainage /

Structure

Relevant

Borehole

/ TP ref

Ground Conditions

Extrapolated/

Inferred CBR

Values

Ch 0 – 200

TP 07 0.0 – 0.6m cohesive made

ground

0.6 – 2.0m Slightly clayey/

silty Sand

CBR 17% - 50%

CBR 24% - 50%

Ch 150 – 450

C&O – 01 – Tertiary

River Crossing

TP 06 0.0 – 0.8m made ground

0.8 – 3.2m soft and very soft

clay (Cohesive

Glacial Till)

CBR 5 - 25%

CBR 5 - 50%

Ch 450 – 800

C&O – 02 – Culvert

Crossing At Ch 520

C&O – 03 – Land

Drain Crossing At Ch

550

TP 05

SJ28NW68

SJ28NW13

SJ28NW47

0.0 – 0.2m topsoil

0.2 – 1.8m sandy silt

1.8 – 3 m soft blue clay

CBR 4% - 10%

CBR less than 1%

Ch 800 – 1000

C&O – 04 – Land

Drain Crossing Ch

820

TP 04

SJ28NW11

0 – 0.2m topsoil

0.2 – 1.2m sandy clay and

clayey silt

1.2 – 2.4m very soft peat

2.4 – 4.6m soft sandy silt

(Glacial Till)

4.6 m stiff clay

CBR 0.5% - 2%

CBR less than 1%




Chainage /

Structure

Relevant

Borehole

/ TP ref

Ground Conditions

Extrapolated/

Inferred CBR

Values

Ch 1000 – 1800

C&O – 05 - 13 -

Various Water

Crossings

TP 04

SJ28NW17

SJ28NW18

SJ28NW8

SJ28NW7

0 – 0.3m soft topsoil

0.3 – 0.5m very soft clay

0.5 m stiff or very stiff

clay

TP 04 and nearest historical GI

suggest that very soft peat can

expected to be found locally.

CBR values not

determined,

however CBR

below 2.5% is

envisaged within

soft clay and very

soft peat

Table 3.2: Scheme B and C - Ground conditions summary

Scheme Borehole / TP

ref Ground Conditions

Scheme B SJ28NW7 0– 0.3 m soft topsoil


0.5 m stiff / very stiff clay

Scheme C SJ28NW22

SJ28NW24

0 – 0.3m soft topsoil


0.5 m very stiff Clay with sand lenses / Sand

Groundwater Conditions

The encountered groundwater levels recorded from recent ground investigation 3.4.13

data and historic BGS borehole logs are presented in Table 3.3




Table 3.3: Groundwater observations nearby proposed Scheme A, B and C.

Chainage Exploratory

Hole

Groundwater level

mbgl AODm

Scheme A

1070 TP04 1.20 3.03

710 TP05 0.30 4.02

300 TP06 1.05 4.36

20 TP07 1.60 (rising to 1.50m)

6.50

1870 (70m offset SE) SJ28NW/7 7.30 6.50

1590 (85m offset NE) SJ28NW/8 8.00 -1.70

1540 (320m offset SW) SJ28NW/9 4.00 2.20

1610 (725m offset SW) SJ28NW/10 4.10 1.30

810 (235m offset SW) SJ28NW/11 1.20 3.30

980 (385m offset S) SJ28NW/12 1.80 4.60

610 (80m offset SW) SJ28NW/13 1.70 3.00

1230 (1610m offset N) SJ28NW/14 0.80 4.30

800 (305m offset NE SJ28NW/15 3.00 1.70

1010 (185m offset N) SJ28NW/16 7.60 -3.20

1270 (98m offset S) SJ28NW/18 5.40 -0.60

1330 (405m offset N) SJ28NW/20 4.20 0.30

Scheme B

870 (95m offset N) SJ28NW/7 7.30 6.50

160 (265m NW) SJ28NW/10 4.10 1.30

2240 (385m NW) SJ28NW/22 7.20 7.20

Scheme C

1300 (Offset 5m W) SJ28NW/22 7.20 7.20




Along the proposed footprint of Scheme A, groundwater seepage has been 3.4.14

observed between 0.3 m and 1.5 m below existing ground level (TP’s 07, 06,05

and 04).

Laboratory Soils Testing

Classification testing to determine natural moisture content, atterberg limits and 3.4.15

particle size distribution were undertaken on soil samples between 0.5m and

0.7m in exploratory holes TP04 to TP07. The test results are presented in Table

3.4

Table 3.4 – Soil Classification Test Results

Exploratory

Hole Depth Index Tests and Classification

MC

(%)

PL

(%)

LL

(%)

PI

(%) Classification

TP04 0.5m 28 27 64 34 High Plasticity (CH)

Clay

(%)

Silt

(%)

Sand

(%)

Gravel

(%)

Cobbles/

Boulders

(%)

Soil Description

TP04 0.50m 46 52 2 0 0 Brown mottled grey slightly

sandy CLAY

TP05 0.50m 32 43 25 0 0 Brown very sandy very silty

CLAY

TP06 0.50m 1 17 82 0 0 Brown mottled grey very

silty SAND

TP07 0.70m 3 89 8 0 Brown mottled grey slightly

gravelly slightly silty SAND




Baseline laboratory test results broadly confirm the soil descriptors provided by 3.4.16

the borehole logs. The single cohesive soil sample tested suggest this material to

comprise a clay of high plasticity (HI). Particle Size Distribution (PSD) tests on

the granular materials also typically conform to the descriptions given by the

borehole logs, presenting a reasonably uniformly graded material with the

predominant constituents of this material comprising fine to coarse Sand. The

PSD testing within cohesive materials suggests more widely graded mix of clay,

silt and sand sized particles.

The results of chemical testing are summarised in Table 3.5. Guidance provided 3.4.17

by the British Research Establishment Special Digest 1:20052 (BRE SD1)

indicates Design Sulphate Class for the material tested to be DS-2, based on the

highest concentration of 0.69 mg/l SO4. This classification suggests an ACEC

(Aggressive Chemical Environment for Concrete) of AC-1s, with a characteristic

pH value above 5.5.

Table 3.5: pH and Sulphate Test Results

Geo-environmental Considerations

Capita Symonds completed a technical assessment (hoylake-Reportv4.0-3.4.18

Aug07.doc) in 2007 which presented the findings of a Phase I Desk Study site

referred to as Hoylake Golf Resort, Wirral, Merseyside. The aim of the Phase I

was to evaluate the ground conditions, environmental setting and geo-

environmental sensitivity of the area.

This study highlighted a number of potentially active pollutant linkages at the 3.4.19

site which could pose environmental risks to human health and the environment.

Exploratory Hole Depth (mbgl) Sulphate SO4 Water soluble (2:1) (g/l)

pH

TP04 2.50 0.690 8.1

TP05 1.50 0.037 9.2

TP06 2.50 0.210 8.4




The presence of a historic landfill in the south-western area of the site could be 3.4.20

potentially a significant aspect to the proposed works and four pollution incidents

have occurred within the site boundary, of which all were “Category 3 – Minor

Incidents”. Two of these involved the release of unknown oil into unknown

ditches; in both cases the source of the pollution was not identified. Another

incident involved the release of storm sewage into freshwater caused by high

rainfall. Eleven discharge consents were shown within the site boundaries. Further

details of these pollution incidents and discharge consents are available within the

Capita Symonds (Structures) Ltd, Phase 1 Desk Study Report for Hoylake Golf

Resort, Wirral, Merseyside..

The area has significant sensitivity with respect to Controlled Water and 3.4.21

therefore controls will be required to safeguard the quality of the various

potential surface water and groundwater receptors.

Other areas around the periphery of the site (small historical gas works to the 3.4.22

north-west and the former RAF station to the south-east) were also identified.

Recommendations included: 3.4.23

Intrusive investigation of the identified landfill area and the areas of possible

infilled ponds/quarries/brick pits.

Installation of gas monitoring wells in possible in-filled areas and subsequent

monitoring for the presence of potentially hazardous ground gases.

Installation of Groundwater Monitoring wells across the site to determine the

hydrogeological regime of the site.

Geotechnical investigation to characterise the ground conditions for structural

loading and possible earthworks.

Investigation of possible on-site groundwater impacts arising from potential

on-site and off-site sources.

Assessment of surface water quality with respect to identified historical

diesel/oil spills.




Information provided by further geo-environmental investigations should be 3.4.24

developed within a geo-environmental risk assessment in line with current

legislation and guidelines. Where risks are assessed to be unacceptable,

recommendations for appropriate mitigation should be considered and assessed

by a competent Geo-environmental Engineer.




Environmental Conditions 3.5

The link road proposals are located within the wider development site and are 3.5.1

subject to some of the environmental issues and constraints that will

undoubtedly be of major significance in the progression of Golf Resort proposals.

It is likely that the highway proposals will need to be considered in the context

of the wider development, and will be included in an Environmental Impact

Assessment. It is also likely that the detailed design of the highway proposals

will seek to complement and contribute to emerging environmental strategy for

the development as a whole.

An environmental search and scoping assessment, focusing on the study area, is 3.5.2

presented in Appendix C3. These documents highlight the significance of of a

number of key environmental issues relevant to the site, including flood risk,

drainage and ecology.

A meeting was held with staff from the Environment Agency to discuss the likely 3.5.3

implications and requirements associated with structural design proposals at

locations where the link road intersects with existing watercourses. This

meeting included consideration of flood risk and ecology and assisted in

determining solutions most likely to receive approval. The minuted from the

meeting are presented in Appendix C.3.

Existing Services 3.6

The approximate locations of existing statutory undertakers services in the 3.6.1

vicinity of the site were obtained via C2 consultation. The diversionary works

associated with Schemes A and B are presented within the following sections of

the report:

Scheme A: Section 5.6 and Appendix C.5 / C.6

Scheme B: Section 6.5 and Appendix D.5 / D.6




4 Site Surveying and Investigation

Topographical Survey 4.1

The topographical survey undertaken for Scheme A is presented in DWGs: 4.1.1

SM16-038 Sheet 1 to 14 (Appendix B.1).

The survey boundary was identified with respect to the clients’ initial alignment, 4.1.2

and assumes a 50m survey corridor width to allow for variation or revision as

part of the design development process.

Geotechnical Site Investigation 4.2

Geotechnical site investigations and historical information regarding existing 4.2.1

ground conditions are included in Appendix B.2




5 Scheme A: Saughall Massie Link Road

Option Identification 5.1

The Hoylake Golf Resort Masterplan and the client initial alignment provide 5.1.1

guidance upon which road alignment options have been developed. The positons

of proposed junctions and the adjacent land boundary constraints have also

been taken into consideration in the development of proposed options.

Two alignment options were identified and are presented in DWG: 5.1.2

CO00205379_F_SchA_001 (Appendix C.1).

Both options propose that the new link road adjoins the surrounding highway 5.1.3

network to the north via Carr Lane, crossing the Liverpool to West Kirby railway

line at the level crossing at Hoylake Station.

Option 1 (Red) proposes that, at the southern section, the road adjoins Saughall 5.1.4

Massie Road at the existing masonry arch bridge, which spans the Newton Brook

watercourse. This alignment option fits within the land available at the time of

the study and requires no additional land acquisition.

Option 2 (Blue) proposes that the new link road adjoin Saughall Massie Road 5.1.5

approx. 160-170m East of the existing masonry arch bridge, subsequently

requiring further land acquisition to accommodate the alignment. The plot

identified for acquisition is located North West of the junction at Saughall Massie

Road, Carr Lane and China Farm Lane and is approx. 16,000 m2 (1.6ha) in area.

The plot currently occupies agricultural farm land, with a residential property

located in the South West corner.

Link Geometry – Horizontal Alignment 5.2

Alignment Option 1 is considered the preferred option because it is fully 5.2.1

accommodated within the land ownership constraints applying at the time of the

study. The geometric design is summarised in the following sections of the

report.




The proposed horizontal and vertical alignment is consistent with the design 5.2.2

guidance provided in DMRB TD9/93: Highway Link Design and is presented in

DWGs: CO00205379_F_SchA_002 and CO00205379_F_SchA_003 (Appendix C.2)

A design speed of 60kph (37mph) has been applied to determine the following 5.2.3

horizontal design parameters, as defined in TD9/93 Table 3:

Stopping Sight Distance (SSD): 90m

Minimum Horizontal Radius: 255m

Maximum Superelevation %: 3.5%

Between chainage 0 – 700m, the geometry aligns closely to that of the initial 5.2.4

client design alignment and consists of curve radii greater than 720m and hence

the design of this section does not require the inclusion of superelevation and

transition curves in order to fully comply with the DMRB design criteria.

Between chainages 1200 – 1400m the alignments deviates slightly through the 5.2.5

use of reduced radii (255m).

Between chainages 1600 – 2100m the alignment deviates significantly from the 5.2.6

initial client alignment in order to achieve a compliant DMRB geometric

alignment. As shown on DWG: CO00205379_F_SchA_003, the alignment

partially encroaches on a pond/lake feature included within the proposals for the

Golf Course Resort development.

Link Geometry – Vertical Alignment 5.3

As noted, a design speed of 60kph has been used to determine the vertical 5.3.1

design speed related parameters defined in TD9/93 Table 3 and are presented

as follows:

Desirable Minimum Crest Radius: 1700m

Absolute Minimum Sag Curve: 1300m




It is assumed that the existing site levels are to be raised generally across the 5.3.2

site of the wider development, in order to address flooding and drainage issues.

In advance of this, the following level parameters have been applied to the

vertical design of the link road:

Proposed surface Carriageway surface generally 300mm minimum above existing

ground levels

Land Drains / Ditch Crossings: + 300mm above existing level

Primary River Crossings: + 600mm above existing level

Between chainages 300 – 1350 the existing site topography is extremely flat and 5.3.3

the vertical design for this section assumes the use of a combined linear kerb

drainage solution as a means of limiting the need for ‘summit and valley’ channel

design whilst providing adequate surface water drainage, through this section of

the alignment.

Structures at Watercourse Crossings 5.4

Outline structures options have been identified and assessed for all watercourse 5.4.1

crossings required to accommodate the proposed link road. The assessment

takes account of relevant design guidance and includes Approvals advice

obtained from an initial meeting with the Environment Agency.

Preferred solutions have been identified for each watercourse crossing and 5.4.2

outline design proposal for these are presented in appended drawings and form

the basis upon which estimated costs have been prepared.

The following documents are presented in full in Appendix C.3: 5.4.3

- Structural Drawings (CO00205379_F_SchA_008 to 012)

- Structural Optioneering Report

- Environmental Agency - Advisory Meeting Minutes




A summary of watercourse crossings and proposed structure types are as 5.4.4

follows:

Watercourse Type Category Structure

C&O(WC) - 01 Tertiary River

Crossing Small Span Culvert

C&O(WC) – 02 Culvert Crossing /

Main River ** Small Span Culvert

C&O(WC) – 03 Land Drain Crossing Small Span Culvert

C&O(WC) - 04 Land Drain Crossing Small Span Culvert

C&O(WC) – 05 Main River Crossing Medium Span Bridge



C&O(WC) - 08 Main River Crossing Medium Span Bridge

C&O(WC) - 09 Main River Crossing Medium Span 2 No. Bridge





** Although the EA advised that Main Rivers should not generally be culverted,

this river is already partially culverted at C&O (WC) – 02. It is therefore assumed

that it will be acceptable to use a box culvert, of greater span/height than the

existing culvert, in this location.




Small Span Structures (Culverts)

For small span structures a box culvert is recommended to carry the proposed 5.4.5

highway. Although planning policy WA2 discourages culverting, for existing

culverts, land drains and tertiary rivers a box culvert is considered sufficient to

allow the watercourse to flow efficiently.

Based on EA recommendations each culvert is to hold a minimum of 300mm 5.4.6

depth of river bedding material, with a mammal ledge.

Each culvert must be designed to ensure river flow is not restricted. At 5.4.7

feasibility stage, this requires the culvert cross sectional area to be equal to or

greater than existing watercourse cross sectional area. The culvert sizes

indicated on the Structures drawings are therefore reasonably generous, and

culvert depth has been maximised by assuming the highway is constructed

directly on top of the culvert.

Depending on the results of the eventual flood risk assessment, to be 5.4.8

undertaken at later stages of design, it is considered likely that at least some of

the box culverts may be reduced in size. This would reduce the cost of box

culverts, and fill could be introduced on top of the culverts. It is also possible

that the results of the FRA might permit downsizing from box culverts to pipe

culverts, which would significantly reduce culvert construction costs. Where a

The approximate reduction in cost associated with providing an alternative piped

culvert solution would eb £40,000 per watercourse location.

See drawing “CO00205379_F_SchA-08”, “CO00205379_F_SchA-09” and 5.4.9

“CO00205379_F_SchA-10” for the proposed feasibility stage box culverts.

Medium Span Structures (Bridges)

For the medium span structures over main rivers (with the exception of C&O 5.4.10

(WC) - 02) a small integral bridge with prestressed reinforced concrete beams

and piled foundations is proposed.




Integral structural form is recommended as it will typically have lower 5.4.11

maintenance and higher durability characteristics than an equivalent semi-

integral or simply supported bridge.

The highway vertical alignment assumes that the road surface is 600mm above 5.4.12

existing ground levels at top of embankment level for main rivers. To ensure

river flow is not affected, the beam and deck thickness therefore needs to be

kept to a minimum. Precast prestressed concrete beams are recommended to

minimise deck thickness.

Piled foundations are very likely to be required at these bridges due to typical 5.4.13

ground conditions expected (soft clay on top of sandstone bedrock).

Depending on the results of further, more specific, ground investigation there 5.4.14

may be potential to reduce construction costs. Firstly, it might be possible to

reduce the diameters of the piles shown on the drawings. Secondly, it might be

possible to change the foundation type from piles to spread foundations.

See drawing “CO00205379_F_SchA-11” for proposed feasibility stage small 5.4.15

bridges.

Roundabout Structure Crossing

The recommended solution is two small bridges, the same as those 5.4.16

recommended at C&O (WC) - 05 & 08, carrying the two sides of the roundabout

over the river. In the centre of the roundabout the river is open to the air. No

diversion of the river is proposed, and no additional land acquisition is required.

Considering the overall construction costs, ecological and flood risk constraints,

this is considered the most suitable solution.

The detailed engineering design of the recommended solution will require careful 5.4.17

consideration to ensure that the arrangement provides adequate visibility for

users of the roundabout, in accordance with the requirements identified in

TD16/07 of the DMRB. It is likely that this may involve careful consideration of

parapet positioning and adoption of systems specifically designed to least inhibit

visibility across the junction and complementary use of high containment

kerbing.




See drawing “CO00205379_F_SchA-12” for proposed feasibility stage bridges at 5.4.18

the roundabout.

Land Requirements 5.5

Option 1 requires no further land acquisition and is within the proposed site 5.5.1

development boundary which applies at the time of the commission. It is

however envisaged that during construction, accommodation works be

undertaken for adjacent landscaping and embankment profiling.

Option 2 requires acquisition of land to accommodate the proposed alignment.

The plot located west of the existing junction at Saughall Massie Road, Carr Lane

and China Farm Lane, in order to accommodate the proposed roundabout and

approach geometry.

Statutory Undertakers 5.6

All Statutory Undertaker (STATS) liaison undertaken for Scheme A has been 5.6.1

chronologically recorded and is presented in Appendix C.5. C2 enquiries were

issued to all utility companies / statutory undertakers in an attempt to identify

potential affected services for the proposed highway link road.

A summary of the companies which have been identified / indicated that their 5.6.2

services are likely to be affected for Scheme A are listed as follows, with

associated C2 response documentation presented in Appendix C.5:

BT (BT)

National Grid (NG)

Network Rail (NR)

Scottish Power (SP)

United Utilities (Sewers) (UU S)

United Utilities (Water) (UU W)

Virgin Media (VM)




A summary of C3 consultation responses received are presented , with 5.6.3

associated C3 response documentation, including diversionary work cost

estimates and preferable design criteria presented in Appendix C.6:

Statutory Undertaker

C3 Consultation Response Summary

Preferable Action Diversionary Cost

(Excluding VAT & NRSWA Discount)

BT - £156,027.78

NG

Minimum depth of cover to be maintained above existing services if achievable.

£80,000.00

NR Not affected on further review

SP Diversionary works to be considered as part of wider development proposal.

£849,034.60

UU (S) Minimum depth of cover of 1200mm to be maintained above existing services.

No cost estimate submitted

UU (W) - £16,000.00

VM Not affected on further review

TOTAL C3 COST ESTIMATE £1,101,062.32




Highway Cross Section and Crossfall 5.7

The proposed carriageway and footpath / cycleway cross section is consistent 5.7.1

with the design guidance provided in DMRB TD27/05: Cross-Sections and

Headroom and TA90/05: The Geometric Design of Pedestrian, Cycle and

Equestrian Routes.

A summary of the proposed cross section is shown below, and is presented in 5.7.2

DWG: CO00205379_F_SchA_004 (Appendix C.4):

Carriageway Width: 7.30m (TD27/05 Fig 4-4a)

Buffer Width: 1.00m (TA90/05 – Paragraph 7.22)

Shared Footpath /Cycleway Width: 3.00m (TA90/05 Table 7.3)

Verge Width: 1.00m (TD27/05 Fig 4-4a)

As stated in TA90/05 Paragraph 7.20 – Table 7.3, the preferred minimum 5.7.3

surface width for pedestrian/ cycle routes segregated by line is 5.0m (3.0m cycle

route and 2.0m pedestrian route), with an acceptable minimum width of 3.0m

(1.5m cycle route and 1.5m pedestrian route).

The carriageway crossfall (excluding sections designed for superelevation) and 5.7.4

footpath / cycleway assumes a 2.5% (1:40) standard crossfall.

Geotechnical Sub-Grade Assessment 5.8

The 2016 investigation indicates that along the alignment of Scheme A 5.8.1

compressible peat and locally very soft to soft clay will be encountered at near

surface level up to 4.6 m bgl. Soil classification tests suggest that natural

cohesive soils at the site should be regarded as being highly plastic. Soft

materials are recorded to be particularly prevalent at the east side of Scheme A.

However, the recorded ground conditions suggest more favorable low

compressible substrata between Ch0 to Ch800. Between Ch800 and Ch1800

significant deposits of low strength highly compressible peat and clay material

should be expected.




The local presence of these very soft and low bearing ground conditions indicate 5.8.2

that the road construction is susceptible to consolidation settlement and

additional measures may be required to reduce post-construction settlement to

an acceptable level and adequate bearing capacity.

The magnitude of settlements depends on the use of engineering fill proposed to 5.8.3

reach the height of the road at completion. The alignment option drawing No.

CO00205379_F_SchA002 and 003 (Appendix C.2) indicates existing levels to be

generally even and indicate a net load increment of approximately 0.5m to up to

1m of material with occasional 2m of infill material will be required. Therefore,

the road can be typically classified as ‘at grade’ with minor earthworks. However

in order to reach road levels a ground surcharge of up to 20 to 45 kPa is

expected and the presence of local soft clay and peat may cause significant long

term settlements.

In order to achieve minimum design CBR values and satisfy settlement 5.8.4

requirements, ground improvement measures may be required. The measures to

be taken depend on available time to construct and road post construction

settlement requirements. The following potential remedial measures to improve

low strength compressible materials should be considered:

Remedial Measures for Poor Ground Conditions

Long-Term Road Maintenance

No ground improvement is undertaken and road pavement is constructed to 5.8.5

proposed level with no additional measures taken to increase bearing and limit

post-construction settlements of the subgrade. This option means less

investment in the short term, at completion stage, but can create significant

risks of settlement over compressive areas of soft clay and peat. Serviceability

issues may occur from post-construction settlements resulting in increased long

term road maintenance and resurfacing periods.




Excavate and Replace

The presence of soft and loose material at subgrade level can be excavated and 5.8.6

replaced with engineered fill to increase allowable bearing pressures and reduce

residual settlements. Given the road size, length of the scheme and percentage

of unsuitable material, the volume of excavation may be expected to be in the

order of 5,000 m3 – 20,000 m3.

It was worth noting that operational costs associated with the removal and 5.8.7

export of unsuitable materials and the presence of contaminated soils should be

considered when assessing a ‘cut and fill’ remedial option.

Earthworks Pre-Loading Surcharge

The temporary application of surcharge load can provide a cost effective option 5.8.8

to reduce post construction consolidation settlements below new pavement.

However sufficient pre-construction time is required to allow the consolidation of

compressible soils.

The total time to reach 90% consolidation of the underlying soils depends on 5.8.9

surcharge loading, thickness of the compressive layer, permeability and

compressibility properties of the material. Based on available ground

investigation data, total consolidation is expected to be exceed 12 months. To

accelerate the consolidation process vertical drainage through the underlying

subsoils can be installed to reduce the pre-construction time. It is envisaged that

temporary stockpiles of material overlying the compressible subsoils in the order

of 5,000 m3 to 10,000 m3 and between 2m and 5m high are envisaged to

effectively consolidate underlying compressible layers.

Recommendations

On review of the historic and recent ground investigation information it is 5.8.10

envisaged that a combination of ‘cut and fill’ and pre-construction surcharging

may prove a suitable solution where there is a desire to minimise over

excavation and reduce the extent of pre-construction works.




Detailed geotechnical design work will be required to determine the surcharge 5.8.11

loading, consolidation durations and most effective phasing for any pre-

construction surcharging work. In advance of this, the feasibility estimate

includes a provisional allowance of £600,000 for Ground Improvement

Preloading Surcharge. This assumes that all excavated topsoil and unacceptable

material (estimated quantity of 16000m3) associated with the road scheme is

used, together with additional imported capping material, and also includes an

allowance for monitoring instrumentation. It is recognised that the opportunity

to co-ordinate the works with those of the wider development and utilise

material arising may offer benefits in terms of cost and time. This should be the

subject of detailed design stage evaluation.

No lime or cement treatment of capping material is considered in this review, 5.8.12

however may also prove a viable option to minimise over excavation of the

subgrade materials. A more detailed assessment is required with further ground

investigation undertaken if the option of chemical material stabilisation is taken

forward.

The thickness of capping and sub-base material should be reviewed at more 5.8.13

advanced stage to ensure that the continuity of drainage from existing capping

and sub-base materials below the existing carriageway will be maintained.

Separation geotextile should be specified when granular capping is placed over 5.8.14

weak cohesive sub-grade to avoid migration of fines into capping material.

Where feasible, soft and compressible localised deposits at sub-grade should be 5.8.15

removed and replaced with granular fill. Soft soil spots can occur anywhere on

the scheme, and they are likely to be prevalent between Ch800 to Ch1800. Sub-

formation material should be proof rolled before pavement construction.

The pavement sub-formation information from this review is preliminary only 5.8.16

and a further review will be carried during advanced design works incorporating

information from further ground investigation.




Additional Ground Engineering Works

It is recommended that additional intrusive ground investigation is required to 5.8.17

further assess the in-situ ground conditions and facilitate the preliminary and

detailed design stages for pavement and structural. Supplementary ground

investigation undertake along Scheme A at the location of the Newton Brook

bridge/culvert (Newton Brook) and adjacent to Saughall Massie Road are

advised.

In addition, watercourses that are recorded as drains, located to the north of 5.8.18

Scheme A, will also require further ground investigation. At these locations it is

recommended that cone penetration testing is carried out with geotechnical and

geo-environmental testing to investigate in-situ shear strength and

compressibility properties to inform preliminary and detailed geotechnical design.

Additional laboratory tests on retrieved soil samples should include one-

dimensional consolidation tests and triaxial tests to establish in-situ

compressibility and shear strength of founding materials

Watercourse Crossings Foundation Assessment

Thirteen watercourse crossings are currently proposed along Scheme A’s 5.8.19

alignment which have been assessed in Section 5.4.

The watercourse crossing locations are presented in Drawings 5.8.20

CO00205379_F_SchA-002 and CO00205379_F_SchA-003 (Appendix C.2)

Section 5.4 of this report categorises each watercourse into one of three spans: 5.8.21

● Small span: tertiary rivers, existing culverts and land drain crossings.

● Medium span: primary rivers.

The suitability of the most appropriate foundation type is subject to further 5.8.22

ground investigation and geotechnical design work, Client preferences regarding

site preparatory works, final levels & costs associated with each foundation

option.




Small span, precast box and pipe culverts generating small bearing pressures 5.8.23

may be supported by trench fill or strip/spread foundations subject review of net

loadings and in-situ ground conditions.

Medium span (up to 8.4m clear span) small bridges and associated wing walls 5.8.24

are likely to require more robust deeper foundation requirements. Peat and fine

grained materials are not considered suitable for the direct support of ground

bearing spread foundations due to their low bearing capacity and compressible

nature.

As an alternative to strip/trench fill foundations, piled foundations may be an 5.8.25

option for structures located in areas of deep loose and soft soils. Piled

foundations should extend into underlying competent material. The safe working

load that may be supported on a pile is dependent on the pile diameter, its

founding depth and the method of installation.

Similarly to medium span structures, the use deep foundations to support 5.8.26

structural and highway loads from a large span/ complex crossing (at

roundabout) is likely on review of the ground investigation data available.

Therefore, without ground improvement or excavation, pile foundations may be

required with loads transferred to competent underlying soils or rock horizons.

The emplacement of piled foundations may require the provision of a piling mat 5.8.27

(working platform) and further advice should be sought from the appointed

specialist piling contractor regarding the proposed plant loadings and resulting

pressures. This data, together with a knowledge of the strength and variability of

the near-surface ground conditions is required in order that design of a mat can

be undertaken in accordance with guidance provided in the 2004 BRE document,

“BR 470: Working platforms for tracked plant”.

Piles can provide an enhanced pathway for the vertical migration of mobile 5.8.28

contaminants. The Environment Agency may therefore object to the adoption of

piles as a foundation solution.

All foundations should be designed for buoyancy on the assuming worst case 5.8.29

flood conditions above finished ground level.




The effects of differential settlements have to be taken into account, in particular 5.8.30

when structures are placed on stiff foundations and total settlements below

foundations should not exceed tolerable limits.

Based on desk study information and recent ground investigation it is likely that 5.8.31

groundwater flows will be encountered in shallow excavations. Excavations may

be subject to flooding, and therefore provision should be made for shoring and

pumping during construction.

Any buried concrete at the site should be designed with a mix with sufficient 5.8.32

resistance in accordance with BRE SD1. Preliminary lab results indicate a

minimum a design concrete class of DC-2 in accordance with Table D2 of BRE

SD1. Although the ACEC classification AC-1s suggests that a concrete class of

DC-1 is adequate, the minimum practical class is DC-2, in terms of allowing

control of cement content.

Road & Footpath / Cycleway Construction 5.9

The proposed road and footpath / cycleway construction is consistent with the 5.9.1

design guidance provided in DMRB HD24/06: Traffic Assessment, HD26/06:

Pavement Design, HD39/16: Footway and Cycleway Design and IAN73/06:

Design Guidance for Road Pavement Foundations.

For the purpose of deriving an assumed traffic flow and commercial vehicle 5.9.2

usage for the proposed link road, Automated Traffic Count (ATC) site data

recorded in October 2015 for the surrounding traffic network has been used. A

conservative assessment has been adopted, comprising transfer of the existing

traffic recorded on Heron Road to the proposed link road, and addition of the

anticipated trip generation data presented in the Hoylake Golf Resort Transport

Assessment (Capita Symonds - July 2007).

A summary of the proposed pavement and foundation construction is as follows, 5.9.3

with full design calculations presented in Appendix C.7:




Flexible Pavement Construction:

Surface Course: 50mm thick Hot Rolled Asphalt (as per WBC Specification)

Binder Course: 60mm thick Asphalt Concrete

Base Layer: 210mm thick Asphalt Concrete

Foundation Construction (Chainage: 0.000 – 800.00):

Sub-base Layer: 220mm thick Type 1 Granular Material

Capping Layer: 220mm thick 6F Material

Foundation Construction (Chainage: 800.00 – 2300.00):

Sub-base Layer: 300mm thick Type 1 Granular Material

Capping Layer: 300.00mm thick 6F Material

Surface Water Drainage 5.10

Between chainages 300 – 1350m, a kerb drainage system such as ACO 5.10.1

KerbDrain is proposed in order to address the flat topography of the site in this

section of the alignment.

A traditional surface channel and gully system is proposed in all other sections 5.10.2

where the topography lends itself to provision of adequate long fall (gradient >

0.5%), with gullies positioned at 30m intervals.

A new 300mm diameter surface water carrier drain has been assumed beneath 5.10.3

the centreline of the carriageway for connection of new gullies, with manholes

positioned at 100m intervals.

It is likely that the discharge and outfall of runoff collected by the highway 5.10.4

drainage system will incorporate appropriate sustainable drainage solutions

(SuDS) that will be developed as part the detailed design. This should, where

possible, include at source storm storage and ground infiltration facilities. It may

be possible to utilise features within the adjacent development site to achieve an

optimised solution.




Junction Design Geometry 5.11

The geometric design of the proposed roundabouts is consistent with the design 5.11.1

guidance provided in DMRB TD16/07: Geometric Design of Roundabouts.

The proposed junctions have been designed to accommodate the swept paths of 5.11.2

a large UK Articulated Vehicle (16.5m Length). Refer to DWGs:

CO00205379_F_SchA_005 and CO00205379_F_SchA_006 (Appendix C.8) for

vehicle swept path analysis.

The proposed junction layout at the intersection with Saughall Massie Road has 5.11.3

been designed to fit within the land constraints at the time of the study. To

achieve a suitable arrangement within these boundaries, the layout incorporates

some features that will require further consideration at the detailed design stage.

In order to accommodate the swept path manoeuvre from Arm 1 (Link Road) to 5.11.4

Arm 3 (Saughall Massie Road East) an entry width of 6.30m is required, in

addition to the use of the central overrun area provided. Refer to DWG:

CO00205379_F_SchA_006 - Vehicle Autotrack 3.

TD16/07 Mandatory Section 7.24 states that: for single lane entry, lane widths at 5.11.5

the give way line must be not less than 3m or more than 4.5m, hence the use of

a 6.30m entry width would require agreement on departure from standards.

Alternatively, this issue could be addressed through road markings / hatching or

localised land acquisition, notably at the North East corner of the proposed

roundabout location.

The entry deflection travelling Westbound on Saughall Massie Road has been 5.11.6

identified as requiring further consideration, due to adjacent land boundary

constraints limiting the allowable junction position and resulting entry arm

alignment. Alignment Option 2 however addresses such issues by providing

greater tolerance in positioning and preferable junction geometry.

A geometric summary of the proposed central development junction layout and 5.11.7

Saughall Massie Road junction layout is as follows:




Inscribed Circle Diameter (ICD): 36.00m

Circulatory Carriageway Width: 5.40m

Central Island Diameter: 20.00m

Overrun Width: 2.60m

Arm 1 (Link Road North) Entry Width: 4.55m

Arm 2 (Link Road South) Entry Width: 4.55m

Arm 3 (Site Development Access) Entry Width: 4.55m

Inscribed Circle Diameter (ICD): 36.00m

Circulatory Carriageway Width: 5.40m

Central Island Diameter: 18.00m

Overrun Width: 3.60m

Arm 1 (Link Road) Entry Width: 6.30m

Arm 2 (Saughall Massie Road - West) Entry Width: 4.45m

Arm 3 (Saughall Massie Road - East) Entry Width: 4.49m

Junction Design Capacity Analysis 5.12

The new Link Road will include two new (3 arm) gyratory junctions, one to 5.12.1

provide access to serve a proposed new Hotel and Golf Resort, which will be

sited adjacent to the existing Municipal Course at Hoylake approximately midway

along the new link road, and the other a three arm roundabout where the new

link road meets Saughall Massie Road.

An assessment of the two new junctions has been undertaken using the industry 5.12.2

standard JUNCTIONS 8 modelling software and the full results to the modelling

are included in Appendix C.9

The junctions have been tested with traffic survey data recorded in October 5.12.3

2015 and an initial sensitivity test conducted which assumes that the existing

northbound and southbound traffic travelling on Heron Road will all transfer to

use the new link road.




A single lane approach to all arms of the site access roundabout has been tested 5.12.4

in the assessment, whilst the proposed gyratory at Saughall Massie Road has

been tested with both single lane approaches to all arms and with dual lane

approaches.

It was noted that the evening peak times varied within the network with traffic 5.12.5

peaks being generated between 15:00 and 17:00. It was evident however that

traffic using Heron Road, A553 Birkenhead Road and Saughall Massie Road

peaked between 17:00 and 18:00 and this hour subsequently formed the base

flows for analysis.

Summary tables are provided below showing the results to the modelled 5.12.6

assumptions at the site access in the AM and PM Peaks respectively;

Summary of Link Road Junction Performance 2015 AM 08:00–09:00

AM

Queue (PCU) Delay (s) RFC LOS

Link Road (N) 0.40 3.99 0.28 A

Link Road (S) 0.45 4.05 0.31 A

Site Access 0.06 3.47 0.05 A

Summary of Link Road Junction Performance 2015 PM 17:00- 18:00

PM


Link Road (N) 0.32 3.77 0.24 A

Link Road (S) 0.63 4.55 0.39 A

Site Access 0.05 3.62 0.05 A




The results to the modelling show that a proposed design with single lane 5.12.7

approaches to the junction would operate within a satisfactory level of capacity

and with no queuing traffic forming on any of the approaches.

A test of the proposed Saughall Massie Road junction with single lane 5.12.8

approaches has been undertaken and the full results are contained in Appendix

C.9.

A summary of the AM and PM Peak results is set out in the following tables. 5.12.9

Summary of Saughall Massie Road Junction Performance 2015 AM 08:00–09:00

AM


ARM 1 Link Road 0.62 5.35 0.38 A

ARM 2 Saughall Massie (W)

1.31 9.17 0.53 A

ARM 3 Saughall Massie (E)

3.67 14.45 0.79 B

Summary of Saughall Massie Road Junction Performance 2015 PM 17:00- 18:00

PM


ARM 1 Link Road 0.45 4.57 0.31 A


0.92 8.05 0.48 A


16.49 53.95 0.97 F




The results to the junction modelling show that the AM Peak operates 5.12.10

satisfactorily however the PM Peak shows that the East approach from the Upton

By-pass and M53 Motorway is approaching saturation, with a recorded RFC

(Ratio of Flow to Capacity) of 0.97 and an associated queue of 16-17 vehicles.

The usual threshold of 0.85 RFC for a junction to operate within capacity is 5.12.11

exceeded under the design for a single lane approach proposal for this junction.

It is however noted that it would be unlikely for all the traffic associated with

Heron Road to transfer onto the new link road and in all probability a proportion

of traffic would continue to travel by the Heron Road route and would not

transfer.

It is therefore acknowledged that the assessment tests a robust scenario of the 5.12.12

potential for traffic to re-distribute on the network, and that in all likelihood a

single lane approach to the junction would suffice. The design would however

benefit from a flare at the junction from the east providing a short dual lane

approach, so as to separate right turning traffic from the ahead movement. This

design proposal would reduce the occurrence of any queueing traffic blocking

back at the junction.

A flare sufficient to accommodate the worst case of 17 vehicles queuing on the 5.12.13

eastern approach is therefore recommended for inclusion within the junction

designs if the highway constraints permit it.

An additional sensitivity test of the PM Peak has subsequently been undertaken 5.12.14

and the network therefore modelled with a 30% reduction of traffic using the

proposed Link Road. This represents a proportion of traffic still using Heron

Road. The results in the following table show that the junction will operate

satisfactorily under this scenario and that a maximum RFC of 0.84 is recorded on

the Eastern approach to the junction with a queue of only 5 vehicles.




Summary of Saughall Massie Road Junction Performance 2015 PM 17:00-

18:00 with 30% of Traffic Maintained on Heron Road

PM


ARM 1 Link Road 0.28 4.02 0.22 A


0.80 6.92 0.45 A


5.08 19.00 0.84 C




Street Lighting 5.13

Refer to Appendix C.10 for Street Lighting Reference Plan. 5.13.1

The following locations have been recommended for the use of street lighting: 5.13.2

Ref Point Chainage (m) Location Description

A 0 - 300 Adjoining Carr Lane / Network Rail Crossing (North)

B 600 - 900 Central Development Roundabout Junction

C 2000 - 2100 Saughall Massie Road Roundabout Junction (South)

It is recommended that the proposed roundabouts, highlighted as Points B and C 5.13.3

above are lit and that the approaches comply with ILP Professional Lighting

Guide 02 “The Application of Conflict Areas on The highway”.

This report details the need to light the approaches based on the category and 5.13.4

speed of the road. A road speed of 40mph requires each junction arm to be lit to

a minimum of 89 metres and is known as the 5 second rule.

Furthermore, it is recommended that the approaches to currently lit areas and 5.13.5

that have a 30mph speed, also apply the 5 second rule and that 89 metres of

road is lit, thereby highlighting the need for a vehicle to reduce their speed.

This is relevant at the northern connection of the new link road to Carr Lane.

The exact position of a change in speed limit from 40mph to 30mph has not

been determined but it is considered likely that an effective speed reduction in

advance of the level crossing would be justified. To this end, a location around

chainage 200m is suggested to contribute to a safe highway environment

serving both the level crossing and a priority junction with Carr Lane. This would

justify provision of continuous lighting for a 300m length of the new road.




6 Scheme B: Improvements to Saughall Massie Road

Existing Link Geometry & Option Identification 6.1

An initial appraisal of the existing link geometry was undertaken in order to 6.1.1

identify sections of the alignment which were deemed non-compliant with design

guidance outlined in DMRB TD9/93: Highway Link Design.

The appraisal assessed both the horizontal curvature and stopping sight 6.1.2

distances (SSD) in each direction, based on existing driver visibility conditions at

the time of this study.

The findings of the appraisal, including geometric compliance, driver visibility 6.1.3

photographs and historical accidental locations are presented in DWG:

CO00205379_F_SchB_001 (Appendix D.1)

Sections of the existing alignment have been identified as being non-compliant 6.1.4

with the design criteria outlined in TD9/93, notably between chainage 250 –

700m. This section of the alignment comprises both sharp changes in horizontal

alignment and a restriction in stopping sight distance due to adjacent vegetation

and hedgerow height.

Re-alignment of Saughall Massie Road, and assessment of the associated land 6.1.5

requirements, is considered to be the most viable means of achieving a design

compliant with the DMRB. The proposed re-alignment option is presented in

DWG: CO00205379_F_SchB_002_Rev P01.2 (Appendix D.3) and discussed

further in Section 6.3 of this report.

The proposed arrangement provides a footpath facility on the southern side of 6.1.6

road. The positioning of this feature was influenced by a review of the likely

diversionary implications for existing services located within the verges of

Saughall Massie Road and how these features may link with similar features

provided in adjacent sections of the road.




Historical Accident Analysis 6.2

A review of Saughall Massie Road’s historical accident data, provided by WBC 6.2.1

and presented in Appendix D.2 was undertaken, in conjunction with appraisal

findings discussed in Section 6.1 of this report.

The review identified distinct correlations between locations of historic traffic 6.2.2

accidents and sections of the existing road that currently provided poor, non-

compliant geometry and visibility.

Examples of such correlation are highlighted at the following chainages 6.2.3

presented on DWG: CO00205379_F_SchB_001 (Appendix D.1):

Chainage 530m / AC-04 (WB)

Chainage 680m / AC-05 (EB)

Chainage 1210m / AC-08 (EB)

At present the imposed speed limit is 50mph through the main link section, with 6.2.4

reduction to 30mph through residential setting. Traffic Automated Count (TAC)

data recorded in October 2015 indicates however that the mean speed limit is

38.6mph (≈ 40mph).

Proposed Link Geometry 6.3

The proposed alignment for Scheme B is derived from a two dimensional, cad 6.3.1

based approach, utilising digital Ordnance Survey mapping and information

obtained during site visits and walkover.

The proposed horizontal alignment is consistent with the design guidance 6.3.2

provided in DMRB TD9/93: Highway Link Design and is presented in DWG:

CO00205379_F_SchB_002_Rev P01.2 (Appendix D.3).

Where possible, the proposed re-alignment has retained sections of the existing 6.3.3

alignment which are compliant with DMRB design guidance, notably between

chainages:




0 – 300m

1000 – 1200m

1280 – 1380m

1640 – 1800m

2120 to 2300m

A design speed of 60kph (37mph) has been used to determine the design speed 6.3.4

related parameters defined in TD9/93 Table 3. Parameters used for design

development are as follows:

Desirable Stopping Sight Distance (SSD): 90m

Minimum Horizontal Radius: 350m

Maximum Superelevation %: 3.5%

Land Requirements 6.4

The required land acquisition, both north and south of the existing Saughall 6.4.1

Massie Road to accommodate the upgrade proposal is highlighted in DWG:

CO00205379_F_SchB_002_Rev P01.2 (Appendix D.3) and summarised below:

North: 3,124m2 (0.31ha)

South: 21,029m2 (2.10ha)

Most of the land acquisition required is adjacent agricultural farm land, with 6.4.2

small sections of residential acquisition required, primarily to provide sufficient

overall width to accommodate addition of the pedestrian footpath / cycleway

facility.




Statutory Undertakers 6.5

All Statutory Undertaker (STATS) liaison undertaken for Scheme B has been 6.5.1

chronologically recorded and is presented in Appendix C.5

C2 enquiries were issued in June 2016 to all utility companies / statutory 6.5.2

undertakers in order to identify potential affected services for the proposed re-

alignment of Saughall Massie Road.

A summary of the companies which have been identified / indicated that their 6.5.3

services are likely to be affected for Scheme B are listed as follows, with

associated C2 response documentation presented in Appendix D.5:

BT (BT)

National Grid (NG)

Scottish Power (SP)

United Utilities (Sewers) (UU S)

United Utilities (Water) (UU W)

A summary of C3 consultation responses received are presented , with 6.5.4

associated C3 response documentation, including diversionary work cost

estimates and preferable design criteria presented in Appendix D.6:




Statutory Undertaker

C3 Consultation Response Summary

Preferable Action Diversionary Cost

(Excluding VAT & NRSWA Discount)

BT - £880,733.94

NG

Minimum depth of cover to

be maintained above

existing services if

achievable.

£660,000.00

SP - £375,644.02

UU (S)

Minimum depth of cover of

1200mm to be maintained

above existing services.

No cost estimate proved

UU (W) - £287,942.00

TOTAL C3 COST ESTIMATE £2,204,319.96




Highway Cross Section and Crossfall 6.6

The proposed carriageway and footpath / cycleway cross section is consistent 6.6.1

with the design guidance provided in DMRB TD27/05: Cross-Sections and

Headroom and TA90/05: The Geometric Design of Pedestrian, Cycle and

Equestrian Routes.

A summary of the proposed cross section is shown below, and is presented in 6.6.2

DWG: CO00205379_F_SchB_003_Rev P01.2 (Appendix D.4):

Carriageway Width: 7.30m (TD27/05 Fig 4-4a)

Buffer Width: 1.00m (TA90/05 – Paragraph 7.22)

Shared Footpath /Cycleway Width: 3.00m (TA90/05 Table 7.3)

Verge Width: 1.00m (TD27/05 Fig 4-4a)

The use of a 5.00m shared footpath / cycleway width is consistent with 6.6.3

improvements works carried out previously at the section of Saughall Massie

Road located east of Three Lanes End roundabout towards Upton By Pass.

The carriageway assumes a 2.5% (1:40) standard crossfall be used on sections 6.6.4

which are not designed to accommodate superelevation.

The footpath / cycleway assumes a 2.5% (1:40) crossfall on all sections of the 6.6.5

alignment, falling towards the carriageway edge for surface water drainage

purposes.

Geotechnical Subgrade Assessment and Road & Footpath / 6.7

Cycleway Construction

Geotechnical Subgrade Assessment

Historic and recent ground investigation information indicates that the 6.7.1

compressive fine grained and peat materials present to the east side of scheme

A may also be encountered within areas of Scheme B and C. However, it is

envisaged that more favourable ground conditions are present in proximity of

existing road infrastructure.




Where unsuitable materials are present at shallow depths the following option is 6.7.2

considered suitable:

Excavation of the full thickness and either:

a) Replacement with suitable aggregate in accordance with Series 600

(Earthworks) of The Highways Agency (HA) “Specification for Highway Works”

Amended 2016, or

b) Screening, selection and replacement (in accordance with Series 600) of

suitable material in engineered layers. Unsuitable materials include loose, soft or

wet materials, biodegradables including topsoil, wood, scrap metal, frozen

material and oversized materials.

The crushing of demolition\hardstand\foundation arisings will generate 6.7.3

aggregate, which (subject to confirmatory testing) should be suitable for use as

unbound pavement materials within the highways, although granular material is

present beneath the majority of the site, it is unlikely to be suitable for re-

engineering.

Ground improvement techniques may be required where upgrade improvements 6.7.4

include the construction of new pavement and poor ground conditions are also

encountered at depth. In order to achieve minimum design CBR values and

satisfy settlement requirements, the use of the remedial ground measures, as

discussed in Section 5.8, are recommended.

The thickness of capping and sub-base material should be reviewed at more 6.7.5

advanced stage to ensure that the continuity of drainage from existing capping

and sub-base materials below the existing carriageway will be maintained.

Separation geotextile should be specified when granular capping is placed over

weak cohesive sub-grade to avoid migration of fines into capping material.

Where the existing pavements are to be widened at grade, the depth of the 6.7.6

capping layer shall be at least as deep as the existing capping layer. It is

considered that a minimum long term CBR of 2.5% may be adopted in most

areas, subject to good subgrade drainage, a thick pavement construction, and

average construction conditions, as defined in IAN 73/06.




The pavement sub-formation information from this review is preliminary only 6.7.7

and a further review will be carried during advanced design works incorporating

information from further ground investigation.

Road & Footpath / Cycleway Construction

The proposed road and footpath / cycleway construction is consistent with the 6.7.8

design guidance provided in DMRB HD24/06: Traffic Assessment, HD26/06:

Pavement Design, HD39/16: Footway and Cycleway Design.

The Automated Traffic Count (ATC) data recorded for Saughall Massie Road in 6.7.9

October 2015 has been used to determine a design traffic flow for pavement

design purposes.

A summary of the proposed pavement construction is as follows, with full design 6.7.10

calculations presented in Appendix D.7:

Pavement Construction:

Surface Course: 50mm

Binder Course: 60mm

Base Layer: 230mm

The foundation construction of the re-aligned sections of Saughall Massie Road 6.7.11

assumes similar ground conditions to that identified for Scheme A, hence the

following thickness are assumed:

Foundation Construction:

Sub-base Layer: 300mm

Capping Layer: 300mm




Surface Water Drainage 6.8

It has been assumed that the existing surface water drainage system between 6.8.1

chainages 0 – 275m is to be retained.

It has been assumed that between chainages 275 – 2300m, gullies will be 6.8.2

installed at 20m intervals on the southern kerbline and 40m intervals along the

northern kerbline.

A new 300mm carrier drain has been assumed for connection of new gullies, 6.8.3

with manholes positioned at 100m intervals along the alignment.

Street Lighting 6.9

Refer to Appendix D.8 for Street Lighting Reference Plan. 6.9.1

The following locations have been recommended for the use of street lighting: 6.9.2

Point Chainages

(m) Description

D 300 - 400 Existing residential section of Saughall Massie

Road.

E 300 - 400 Proposed re-alignment section of Saughall Massie

Road.

F 1080 Existing residential section of Saughall Massie

Road, junction at Carr Lane and China Farm Lane.

G 2300 Saughall Massie Arm of Three Lanes End

Roundabout.

H 2300 Heron Road Arm of Three Lanes End Roundabout.

I 2300 Pump Lane Arm of Three Lanes End Roundabout.




It is recommended that the lighting which exists at Point D, with an imposed 6.9.3

30mph speed limit apply the 5 second rule, hence 89m of lit road, and that Point

E be relit with new lighting appropriate to its new use.

It is recommend that the singular lighting column, highlighted as Point F has its 6.9.4

lantern replaced for an LED version. It is further recommended that this lantern

provide adequate lighting control to meet with G3 in compliance with BS EN

13201-2:2003. It would appear that the front of the existing lighting unit has

been masked, possibly due to being a deemed a nuisance to local residents,

hence affecting the operating performance of the lantern at present.

It is recommended that the existing lit roundabout approach, highlighted as 6.9.5

Points G, H and I are extended to comply with the 5 second rule, hence a

minimum of 89 metres of lit road.




7 Scheme C: Improvements to Heron Road

Technical Review of Design Proposal & DMRB Compliance 7.1

A technical review of the proposed highway improvements to Heron Road has 7.1.1

been undertaken in accordance with current DMRB design standards. The review

has been undertaken using the proposal drawings presented in Appendix E.1

Design Speed

Note: The proposed design speed specified on drawings: 214059-0101-Con_p1 7.1.2

and 214059-0104-Con_p1 denotes a transition from 30mph on approach /

departure of the roundabout junctions located at both Saughall Massie Road

(Three Lane Ends) and Birkenhead Road, to 60mph through the main link

section of Heron Road.

It is assumed for the purpose of technical review that the adopted design speed 7.1.3

for highway improvements is to be 60kph (37mph) through the main link section

of Heron Road, as is the case for Schemes A and B.

Cross Section

The proposed cross section for the highway improvement of Heron Road is 7.1.4

summarised as follows and deemed compliant with the relevant sections of

current DMRB design standards noted aside:

Carriageway Width: 7.30 m (TD27/05 Fig 4-4a)

NMU Width: 3.00 m (TA90/05 Table 7.3)

Verge Width: 1.00 m (TD27/05 Fig 4-4a)

Horizontal and Vertical Alignment

Based on the site location, it is assumed that the area be considered urban; 7.1.5

hence application of Superelevation is to be limited to a maximum of 5%. The

road type is considered all-purpose single carriageway, hence the desirable

maximum vertical grade is to be limited to 6%.




The minimum horizontal curve radius applied between chainages 750-950 is 7.1.6

90m, hence three steps below desirable minimum radius with Superelevation of

7%. For the use of such radii, in conjunction with the proposed Superelevation

of 5%, a departure from standards is required.

The use of transitional curves has been omitted from the design in several 7.1.7

sections of the link alignment, notably between chainage 700 to 1000m were the

radius is considerably reduced. In accordance with TD9/93 Paragraph 3.15,

transitional curves shall be provided on curves the radius of which is less than

that shown in TD9/93 Table 3.

A summary of the vertical geometry is as follows: 7.1.8

Min Crest Curve: 5020 m (> Desirable Minimum 1700m)

Min Sag Curve: 3000 m (> Desirable Minimum 1300m)

Min Gradient (Straight): 0.200 % (< 0.5% Gradient)

As defined in TD9/93 Paragraph 4.3, for effective drainage with kerbed roads a 7.1.9

minimum of 0.5% should be maintained wherever possible. From review,

sections of the proposed vertical alignment, notably between chainages 250 to

600m are 0.260%, hence further review of the drainage / channel profile is

required.

Stopping Sight Distance (SSD)

The minimum SSD through the main link section is 70m, hence one step below 7.1.10

the desirable minimum. However, on EB approach of Birkenhead Road it has

been noted that visibility of 50m exists, hence a departure from standards would

be required.

Junction Geometry

The proposed roundabout junction design located at Birkenhead Road has been 7.1.11

reviewed in accordance with the design criteria outlined in TD16/07. A summary

of the roundabout geometry is as follows:




Central Island Diameter: 28.00 m

Inscribed Circle Diameter (ICD): 42.00 m

Circulatory Carriageway Width: 7.00 m (No overrun area shown)

Stopping Sight Distance (SSD): 50.00 m (East Arm)

In accordance with TD16/07 Paragraph 7.8 (Mandatory), the width of circulatory 7.1.12

carriageway must be between 1.0 and 1.2 times the maximum entry width,

hence taking the maximum entry width to be 7.40 for multi-lane entry, the

circulatory carriageway width is deemed non-compliant and a departure from

standard required.

Single Lane Geometry:

Entry Width (Max / Min): 5.85 / 5.35 m

Exit Width (Max / Min): 5.85 / 4.35 m

Multi-Lane Geometry:

Entry Width (Max / Min): 7.40 / 7.25 m

Exit Width: 7.50 m

In accordance with TD16/07 Paragraph 7.24 (Mandatory), lane widths at the 7.1.13

give way line must be not less than 3m or more than 4.5m, with the 4.5m value

appropriate at single lane entries and values of 3 to 3.5m appropriate at

multilane entries. Hence, both single and multi-lane entry widths proposed are

greater than the mandatory requirement.




8 Cost Estimates

Scheme A 8.1

Saughall Massie – Scheme A Bill of Quantities (BOQ/001)

Summary of Cost Estimate (Appendix C.11)

Series Item Description Cost (£)

100 Preliminaries £136,837.88

200 Site Clearance £8,500.00

300 Fencing £125,300.00

500 Drainage and Service Ducts £230,505.10

600 Earthworks £1,156,187.50

700 Road Pavements - General £1,150,311.00

1100 Kerbs, Footways and Paved Areas £465,593.19

1200 Traffic Signs and Road Markings £3,095.00

1300 Road Lighting Columns and Brackets etc. £5,000.00

1400 Electrical Works for Lighting £29,800.00

1700 Structural Concrete / Bridge Works £1,405,000.00

2700 Accommodation Works and Statutory Undertaker £1,111,062.38

3000 Landscape and Ecology £5,460.00

Optimism Bias Add 44% of estimated Cost

(Series 2700 not included) £2,077,499.46

TOTAL £7,910,151.51




Scheme B 8.2

Saughall Massie – Scheme B Bill of Quantities (BOQ/002)

Summary of Cost Estimate (Appendix D.9)




300 Fencing £107,390.00


600 Earthworks £375,212.46

700 Road Pavements - General £905,665.25




1400 Electrical Works for Lighting £18,322.00

1700 Structural Concrete / Bridge Works £320,000.00

2700 Accommodation Works and Statutory Undertaker £2,234,819.96



(Series 2700 not included) £1,112,791.40

TOTAL £5,876,682.72




Scheme C 8.3

Saughall Massie – Scheme C Bill of Quantities (BOQ/003)

Summary of Cost Estimate (Appendix E.2)




300 Fencing £102,389.00


600 Earthworks £379,158.84

700 Road Pavements - General £880,830.05




1400 Electrical Works for Lighting -

1700 Structural Concrete / Bridge Works -

2700 Accommodation Works and Statutory Undertaker £5,000



(Series 2700 not included) £861,370.53

TOTAL £2,824,030.81




9 Conclusions and Recommendations

This report presents and summarises the feasibility work undertaken in response 9.1.1

to a brief prepared by the Client, Wirral Borough Council. The work considers

the feasibility of providing specific highway infrastructure improvements that

would provide access and support the Hoylake Golf Resort Development.

The feasibility study identifies preferred options for the provision of a new road, 9.1.2

the Saughall Massie Link Road, referred to a Scheme A, and for the improvement

of a section of the existing Saughall Massie Road, referred to as Scheme B. Both

schemes complement the Golf Resort Development proposals and also offer

wider strategic benefits to the highway network.

The study also includes a review of the design and costs associated with an 9.1.3

existing highway improvement proposal for Heron Road, referred to a Scheme C,

which is located to east of the Golf Resort Development site.

The preferred option for Scheme A provides a road alignment and junctions that 9.1.4

comply with the relevant geometric design guidance set out in the Design

Manual for Roads and Bridges. This proposal develops the road alignments

indicated in the Golf Course Development proposal and the Client’s initial road

alignment, takes full account of constraints within the site and fits within the

understood boundaries of land available. The proposed junctions have been

tested to demonstrate that they will provide sufficient capacity for the expected

traffic demand.

An intrusive ground investigation and feasibility stage geotechnical assessment 9.1.5

was carried out to provide a broad understanding of the ground conditions likely

to be encountered and inform an initial assessment of the ground engineering

and road foundations required for the new road. This work identified that the

southern section of the new road is likely to be underlain with weak

compressible ground, where more extensive ground engineering measures are

likely to be required to support the permanent construction.




The report suggests that employing pre-construction ground surcharging to 9.1.6

improve the ground in this section may be a viable and cost effective method,

given the nature of the ground and depth of the water table. The report

indicates that this approach would require a significant time period for

consolidation and would require significant quantities of temporary material.

Whilst more work is required to develop this approach, the potential to consider

the construction of the road within the programme for the development of the

Golf Course site as a whole is considered to be an opportunity that could have

significant benefit. It is therefore recommended that this should be explored

during further development stages.

Scheme A crosses a number of existing watercourses along its length. Many of 9.1.7

these are minor land drains and ditches that have been installed to promote the

cultivation and agricultural use of the land in this area. Box culvert structures

are proposed as the most appropriate means of bridging these watercourses.

However, this requirement should be reviewed during future design stages with

respect to the flood management and land drainage measures associated with

the Golf Course Development,

Scheme A also crosses three designated main rivers at Newton Brook, The Birket 9.1.8

and Carr Drain. Open span bridges are proposed at these locations, recognising

the preference of the Environment Agency for reducing fragmentation and

maintaining ecological quality. An initial meeting with the EA was held to

consider the environmental issues relating to the watercourse crossings and gain

an understanding of the solutions most likely to receive approval. The

intersection of the preferred alignment and the existing Saughall Massie Road

coincides with a meandering section of Newton Brook. The EA have provided

feedback regarding this location, which indicates their preference, if possible, for

either the junction to be relocated or the watercourse diverted. The EA

acknowledge that both of these options may not be possible due to land

ownership issues and, if this remains the case, would prefer a scheme that

maintained an open river within the roundabout.




It is noted that the study includes a second alignment option which locates the 9.1.9

junction to the east. It is also noted that, the implementation of Scheme B

would result in a relocated junction position that would address some of the

complexities associated with the current proposal. These options and variations

may be the subject of further consideration during later stages of development.

The EA have also recognised that the development provides an ideal opportunity 9.1.10

for Sustainable Drainage Systems (SuDS) with options for features such as

retention ponds, reedbeds, swales and porous pavements. This is considered to

be applicable to the wider development site within which the new road will run,

particularly given the likely creation of ponds and lakes within the layout of the

Golf Courses. It is anticipated that the design of the Golf Course Development

will be guided by the findings of Flood Risk and Environmental Impact

Assessments and, that the drainage, earthworks, topography and waste

management strategies adopted across the site will also be applicable to the Link

Road.

In February 2016 Wirral Council submitted proposals for Schemes A and B to the 9.1.11

Liverpool City Region Transport Advisory Group for the assessment of scheme

options to be considered for scheme entry into a Strategic Pipeline Investment

Programme. Wirral Council intend to prepare and submit Major Scheme

Business Cases for Schemes A and B, for funding approval. This feasibility study

provides developed technical proposals and detailed cost estimates that are

considered a suitable and robust basis for informing the commission and

progression of Major Scheme Business Cases for Schemes A and B.




10 Appendices

Feasibility Report - Wirral CouncilFINAL-REV-1).pdf · Feasibility Report Saughall Massie Link Road – Feasibility Study Doc Ref: CO00205379/DOC/FR Rev 1 September 2016

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