Masonry Arch Bridge Reinforcement – ‘XiSPAN’

Matt Hunt

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Masonry Arch Bridges

• Over 25,000 on railways in the UK, 200,000 in Europe• Many over 100 years old • Increased tonnage and increased line speeds • Heavier use on diversionary freight routes

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XiTRACK Concept

2-component polyurethane, with designable properties Mixed on-site at point of application and poured over ballast Penetrates and captures ballast stones in a strong matrix

– Utilise compressive strength of ballast– Tensile strength provided by polyurethane

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Existing situation

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Stress and Loading

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Intense loads

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Distributed Loads

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How it works

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Analysis (LimitState:Geo)

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Installation ‘the easy bit’

ResultsMonitoring

• Creating a ‘standard detail’ option, which would be over designed on most bridges but avoids the full design process for each structure

• Inclusion of waterproofing

Development

• Can be delivered now• Can easily be incorporated with track renewals• Spandrels can be protected with upstands or beams• Removal of DTS ‘prohibited’ status• Longer lasting remedial work such as pointing

Operational Benefits

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Concrete saddle Sprayed concrete Steel anchors XiSPAN

Impact Intrusive, new response modes

May reduce clearance, visually intrusive

New response modes, intrusive

Minimal structural and visual impact

Can be ‘tuned’

Inspection New inspection requirements No new inspection requirements

Installation Requires removal of track & full depth fill removal, time consuming

May require closure of road below

Intrusive, time consuming

Simple, rapid, short possessions

Partial fill removal

A ‘standard detail’ option

NWR Partnership Awards

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