Presentation TitlePresentation TitlePresentation TitlePresentation TitleThe Hooley Cutting Stabilisation Project

YGG – Geotechnics in the Rail Industry

Andrew J O’Donovan - BAM Ritchies

Introduction

• Why is this project relevant to the future of rail?• Background to the project• Design and Methodology Development

– Feasibility and Options• Implementation

– Enabling works– Main scheme– Resident interaction

• Safety and the Public• Innovation and Best Practice• Lessons learnt for the future

Project Teamand Stakeholders• Customer – Network Rail• Main Contractor – BAM – an integrated delivery team of

BAM Nuttall Rail and specialist ground engineering contractor BAM Ritchies

• Designer – Arup• Principal stakeholders

− Travelling public including Gatwick Airport passengers

− Train operating companies− Local residents− Local businesses including adjacent petrol station− Protected species of Roman Snail

History• Two adjacent cuttings

• 10-miles north of Gatwick

• Built c.1850

• 30m deep

Ground Investigation• 21nr BH; rotary follow-on up to 30m

• Rope access face inspection

•Window Samples and Trial pits

Ground Investigation

Feasibility Study

Dry Valley GravelsDry Valley GravelsDry Valley GravelsDry Valley Gravels

Enabling Works

• Nine day Christmas blockade

• 1000 lin-m of temp catch fence

• 260 lin-m of scaffold deck

• Improvements to RRV access point at the nearby mud flats

Main Works• 14,000m3 excavation• 55,000 lin m of drilling

– 3 types of drill rig• Beam and Grillage

– 220m3 spray concrete• Upside crest beam• 18,0002 meshing• Auxiliary works

– Demolition of two properties

– upper catch fence– removal of enabling works– reinstate 24nr gardens

Partial rePartial rePartial rePartial re----grading, soil nailing and mesh facinggrading, soil nailing and mesh facinggrading, soil nailing and mesh facinggrading, soil nailing and mesh facing

Soil nailing and mesh facing

Scheme Design

Area 1 - Tunnel Houses (up-line)

Upside crest view north

Upside crest looking north

Section 2 - Esso Houses (up-line)

Construction – Upside

Upside crest view north

Upside crest view south

Section 3 - Beam & Grillage

New beam and grillage

New beam and grillage

New beam and grillage

New beam and grillage

Previous Beam and Grillage Construction 2001

Section 4 – Central Spine (down-line)

Section 4 – Excavation and re-grade

View north to spine

View south from spine

Construction Issues

THE ROMAN SNAIL!THE ROMAN SNAIL!THE ROMAN SNAIL!THE ROMAN SNAIL!

• One team approach• Collaborative working• Observation cards from all on site• Safety committee meeting• Joint NR safety tours• Refined look-out system• Emergency procedure

– abseil rescue– line protection procedure

• High risk activities– operational railway– plant movements– working at height

Safety

• Steep slope working• Lightweight plant and equipment• High output plant• Methodologies• Latest high strength meshes• Training and safe systems• Use of sprayed concrete for Beam and Grillage• Bespoke temporary safety barriers to protect track and trains• Improved look-out system

Innovation and Best Practice

• Collaboration between Customer, Main Contractor and Designer makes for a better project

• One team approach provides for a integrated solution• Carefully developed safe systems of work enable work to be

undertaken while train operations continue as normal • Using modern advanced materials enable a ‘Do and forget’

approach• Use of active high strength materials rather than containment

materials• Everyone buying into a common safety regime leads to

improvements• Consideration of whole life costings essential on critical

structures especially on high use lines

Lessons Learnt

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