Risk Review...• 100 % TWS check to ensure all bolts are engaged. (TWS SIGN OFF) • Infills installed and TWS to sign off prior to loading. (TWS SIGN OFF) • Carpenters install

Risk ReviewStage 3 Bridge Decks A and B

Overview

Bridge deck B - 3 No. bays.Bridge deck A - 3 No. bays.

W/C 10th

October

W/C 28th

November

Grouting of the bridge bearings

• Once handover is received from CBUK the bearings will be grouted up.• Scaffold to be installed around crossheads to bearing shelf level to allow access.• Bearing to be grouted in 2 stages:

1) Grout pockets to top of plinth2) Install shutter and grout to underside of bearing (20mm allowance in design- 10mm minimum required)3) Conbextra HF grout to be used for both stages.

Installation of the permanent formwork to the bridge beams

• Cordek panels to be installed between the bridge beams (braced pairs already installed to beams by CBUK prior to installation); all terrain scissor lifts used from ground slabs or crane matt below.

• Ensure Permit to Load is signed off by TWS prior to access from above on the cordek panels.

Scaffolding requirements

• Before entry to the beams permit to load signed by TWS.

• Full external scaffold to external girders prior to entry. Welded 60 diameter bolts on girders to receive scaffold tube for edge protection.

• Bricksguard to be attached to scaffold.

Installation of mesh to bridge decks

• Mesh installed to acoustic infill and outside sections of bridge decks (external mesh ties to shear studs prior to beams being lifted into position).

• Access to the infill sections will begin from the East and progressively to the West.• Mesh lifted in using tower crane.

Installation of fixings

• Installation of Halfen wavytails at every other hole- remaining holes plugged. Additional wavy tails where there are hanging signs in the main concourse may be required. STQ to be answered specifying positions.

• Installation of dywidag receivers for paraslims.

Concreting of the infill sections

• 5 No Total infill bays for bridge deck A & B

• Pour sequence: - Bays numbered 1 first - Bays numbered 2 second

Total pour time 4 HOURS

Method to pouring infills

• Scaffold deck built beforehand and lifted into position spanning between the bridge deck girders

• Concrete pump to be set up in the concourse on the crane matt or slab (Concrete to be pumped on nights)

Paraslim methodology

Installation

• Paraslims to be made at Edmonton/ O’Hagan’s yard and checked off by TWS prior to being loaded to come to site. (TWS SIGN OFF)

• Permit to load tag installed to signify that the paraslim has been checked and is ready for lifting in to position.

• Crane to stay clipped on to paraslim until all diagonal paraslim ties are installed to brackets above. (TWS SIGN OFF)

• Crane releases paraslim and then all horizontal ties are secured to web of beam.

• Paraslims to be secured from MEWP below and from inside handrail on the bridge deck above.

• 100 % TWS check to ensure all bolts are engaged. (TWS SIGN OFF)

• Infills installed and TWS to sign off prior to loading. (TWS SIGN OFF)

• Carpenters install combisafe to edge of paraslim and therefore allow removal of inside edge protection and full access to the bridge deck.

• Repeat process.

Paraslim methodology

Removal

• Briefing to all involved in task prior to striking: Carpenters, Scaffolders, Crane ops & Engineers.

• Permit to unload once concrete achieves strength. (TWS SIGN OFF)

• Scaffolders reinstall inside edge protection along section where paraslims are to be removed. To be suitable for fall restraint anchorage point.

• Exclusion zones in place & loose materials removed.• Scaffold bracing & timber infills to be removed first.• Crane takes weight of the paraslim once lifting eyes are

exposed.• Carpenters to remove diagonal dywidag bars from

bridge deck with fall restraint harness.• Carpenters then remove horizontal ties which releases

the paraslim from the bridge deck.• Repeat process.

Installation of the permanent formwork (Paraslim)

• Edge protection and scaffold deck for access

Installation of the reinforcement for bridge decks

• Levels to be checked by the engineer – set by EDM to ensure falls and cover• Drainage channels to be set out• Starters for upstand walls

Installation of starter bars for acoustic walls and elephant ear brackets

• Installation of precast platform wall unit (acoustic walls) starter bars.• Bars to be set out by engineer or surveyor.• Elephant ears brackets to be set out by surveyor.• Two sets of acoustic walls starters on bridge deck C.

Concreting of bridge decks

• 2nd Stage pour – structural slab• Levels to be checked throughout pour by engineer – as per oversite slab• Screed rails to be placed by survey.

Striking of parapet formwork