Integral Rail Bridge ConstructionStamford Underbridge,Werrington Grade Separation

Rupert Noronha

Section Engineer

Morgan Sindall

Project Location

Outline

• Werrington Grade Separation – Project Overview

• Integral Bridges – What are they? What are the benefits?

• Stamford Underbridge – Interface with WGS and Staging

Bridge Innovations on Stamford Underbridge

1. Original vs New Construction Sequence

2. Detailing Issues with Integral Bridges

ClientDesigners Principal Contractor

Contract Value - $360M AUD

Integral Bridges

• Monolithic superstructure and substructure creating a full moment connection

• No expansion joints or bearings

• Thermal movement and braking loads accommodated by abutment

• Different to Semi Integral – bearings but no expansion joints

• Reduced initial cost

• Better rideability – no joints

• Lower maintenance – no joints or bearings

• Lower whole of life cost

What are they?

What are the benefits?

Simply Supported

Spans typically less than

70m in length and less

than 30 degree skew

Integral Bridge

GNGE Line

East Coast Main Line

Diverted Brook

Access Road

Slewed Stamford

Lines

160m curved jacked box

Commercial

NewSouth Ramp

Stamford Underbridge

Plan and Elevation

Stamford Underbridge

South Ramp

N

Reinforcement

Cage

Bored Piling – Temporary Casing

After

Before

Pile Cropping

After

Before

AfterBefore

Blinding for Capping Beams

After

Before

Capping Beam Reinforcement

After

Before

Capping Beam

ReinforcementFormwork

N

Steel Prop

Cast in Items

Stamford Underbridge

Capping

Beams

Capping

Beam

Pour

Abutment Piles

• When working next to rail infrastructure the best risk control is by preventing trains from running on a line (ie. blocking the line)

• Where not practicable (eg. the work requires consistent work during a shift) working with lines open to traffic is permissible under adjacent line open (ALO) conditions

Adjacent Line Open (ALO) Working

ALO Working – trains permitted

Stamford Underbridge

South Ramp

N

Non ALO Working

“Plant which cannot foreseeably reach the fouling point of a line at

maximum reach (including load) including human error requires a risk

assessment and a method to ensure the distance does not reduce”

Nearest Running Rail

Foul Point

Bridge Abutment

Precast Mould

Maintenance Walkway Brackets

Original Sequence

2

1

3

5

5

Revised Sequence

1

2 233 3

45 5

• What am I lifting and how heavy is it?

• What platform will be required to support the

crane?

• Where are the support points on the beams?

• What is the closest location I can lift the beams

in from – smaller crane saves $$

• Are any temporary closures required?

• Where will the beam supply vehicle be located?

• How are fall and foul risks controlled in relation

to rail lines, power lines etc?

Planning a Lift

Outrigger mats delivered

Chains secured to lifting points

Deck

erection

Detailing Issues

Stitch pour reinforcement between deck units bars

clashed with adjoining deck unit. These needed to

bent on site to land the beams.

Stitch

Pour

Rebar

1

2

B09

B14

Coupler

Available tolerance is L2 – L1 = 63mm

Fixed Bar (L-Bar)

Continuation BarTorque

Wrench

The more thread visible indicates more

tolerance was required!

Solution - Revised Detail

Solution: Couple Bar 14s and Bar 28s

Abutment

Reinforcement

Abutment and

Deck Pour

Abutment and

Deck Pour

Bridge Deck - Complete

Waterproofing

Track Foundation

Walkway and OLETrack Install

Underbridge Excavation Access into Wideway

Stamford

Underbridge

South

Ramp

East Coast Main Line

Great Northern Great Eastern Line

Slewed Stamford

Lines

South Ramp

Curved Jacked

Box

Stamford Underbridge

160m Precast Jacked Box

Removal of East Coast Main Line

Jacked Box pushed under ECML in 9 Day Rail Blockade

Reinstatement of East Coast Main Line