mersey gateway bridge project · 2015. 3. 12. · mer-cjv-rep-tmp-07-510131 1 12 march 2015 1...
TRANSCRIPT
-
MERSEY GATEWAY BRIDGE PROJECT
MERSEYLINK CONSTRUCTION METHOD REPORT SECTION 7 WESTON LINK MARCH 2015
MER-CJV-REP-TMP-06-510131
-
Construction Method Report Section 7 – Weston Link
FORWARD POINT OFFICE
Document Control Sheet Rev. Status Revision History Date By Check Approved
- PD For Planning Discharge 12 MAR 2015 MM TG SG
Merseylink CJV Forward Point Tanhouse Lane Widnes Cheshire WA8 0SL Tel: +44 (0)1928 785700
-
Construction Method Report Section 7 – Weston Link
FORWARD POINT OFFICE
Table of Contents
1 Introduction ............................................................................................................. 1
1.1 Introduction ................................................................................................................. 1
2 Description Of The Works ...................................................................................... 1
2.1 Road Works ................................................................................................................ 1
2.2 Structures ................................................................................................................... 2
Figure 1 Ineos Chlor Retaining Wall ..................................................................................... 2
Figure 2 Equestrian Bridge .................................................................................................. 5
3 Site Access .............................................................................................................. 5
4 Site Clearance .......................................................................................................... 6
5 Utilities Diversions .................................................................................................. 6
6 Construction Vehicles And Numbers .................................................................... 6
7 Traffic Management ................................................................................................ 7
8 Environmental Issues ............................................................................................. 8
8.1 Construction Environmental Management Plan .......................................................... 8
Appendix A – Support Documents ................................................................................. 9
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 1 12 MARCH 2015
1 Introduction
1.1 Introduction
1.1.1 This report describes the construction methods that Merseylink will adopt in order to
construct the new works within Section 7 Weston Link. This will include major elements
such as the contiguous piled retaining wall, an equestrian bridge, associated footpaths
and a new on-slip merge lane within. It will also outline the proposals for the partial
demolition of the existing western expressway over-bridge (Rocksavage West Bridge) at
this junction.
1.1.2 The report augments the information contained in the Construction Methods Report (ref
MER-CJV-REP-TPL-00-5100011) for the entire Project which has already been partially
approved by the local planning authority.
2 Description of the Works
2.1 Road works
2.1.1 Section 7 includes the Western Point Expressway, Western Link (Northbound link) and
the Western Point Expressway junction.
2.1.2 The road works include the construction of a new Western Point Expressway; west to
north bound link slip road; and amendments to the existing Western Point south to north
bound link road. These works include all roadway merge and diverge arrangements to
meet current geometric standards.
2.1.3 The new Western Link road will be constructed to allow a left hand merge and result in
the removal of the existing right hand side merge to the existing Western Link.
2.1.4 The links will be accommodated by single lane slip roads. These works will comprise
modifications to the earthworks and highway alignments and the construction of a new
retaining wall to accommodate the new link road.
2.1.5 The outline construction process is as follows:
Complete main utility water main diversions.
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 2 12 MARCH 2015
Construct new contiguous piled retaining wall (known as the Ineos Chlor Retaining
Wall)
Construct new equestrian footbridge
Complete new earthworks and associated road works with the slip roads.
Demolish part of the existing Rocksavage West Bridge
Demolish the old western to Central link –(South bound)
Construct a new ramped footpath – equestrian way
2.2 Structures
2.2.1 Section 7 includes two new structures, Ineos Chlor Retaining Wall and the Equestrian
Bridge.
Ineos Chlor Retaining Wall:
2.2.2 This new retaining wall will be constructed with contiguous piles to form a cantilevered
wall. The wall will be faced with insitu concrete. This retaining wall will allow the new
Western Point Expressway to Western Link Road to be constructed.
Figure 1 Ineos Chlor Retaining Wall
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 3 12 MARCH 2015
2.2.3 The construction sequence is described below:
i. Retaining Wall
Prior to commencing construction of the new wall a pair of 400mm PE water mains
will be directionally drilled from the north side of the wall beneath the existing Western
Point Expressway and to the south side of Rocksavage viaduct.
The water main will also include a section of conventional open cut pipe work to
complete the diversion work. The final connection and transfer of the water supply
from the existing main to the new diversion will be phased during the construction of
the piled wall.
The existing ground and existing northbound link will be filled with suitable material
to form a piling platform to the south side of the retaining wall. The piling rig will be
situated to the south side to ensure that no damage occurs to the existing 600mm
water main and the newly diverted section.
Piling works will commence at the western end of the piled wall and progress towards
the existing water main located within the existing footpath to the south of the Mormon
Church. Prior to continuing with the piling operations the new main will be connected
once the first section of piling has passed the section of drilled pipework. At the time
of writing this report United Utilities are investigating the possibility of making final
connections prior to piling operations
With the water main diversion completed the remaining section of the piling works
can be completed.
The new retaining wall also forms part of the Equestrian Bridge sub structure. With
the substructure completed the new bridge deck can be cast.
The main retaining wall is also clad with a new concrete face.
Upon completion of the structures work the bulk earthworks and road works
operations can commence.
Equestrian Bridge
2.2.4 The bridge is required to carry the existing bridleway over the new link road. The bridge
will have a width of 3.5m to allow for combined pedestrian and equestrian use. The road
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 4 12 MARCH 2015
below will be a single lane urban all-purpose connector road comprising 2.5m west verge,
3.3m hard shoulder, 3.7m carriageway, 0.3m hard strip and 2.5m east verge.
2.2.5 In order to cross the proposed road, the structure will have a clear span of 12.2m, which
is easily accommodated in a single span. The structure will be provided with a width of
3.5m between parapets to allow for pedestrian and equestrian use. This relatively small
span can be accommodated in a single span reinforced concrete deck founded on a
contiguous piled wall foundation. As this bridge is located in a ‘green field’ site ‘top down’
construction is adopted to minimise the risk of working at height (see 2.2.8 below).
2.2.6 Either side of the west abutment the will be Ineos Chlor Retaining Wall, this will also be
constructed using contiguous bored piling, and will be finished to match the Equestrian
Bridge. Movement joints will be provided between the bridge and the retaining wall.
2.2.7 The approaches to the bridge will generally be formed of earth slopes. However, local to
the ends of the deck a reinforced concrete slab will be provided to act as the supports to
the equestrian parapet. At the west end of the crossing the structure interfaces with the
proposed new Ineos Chlor retaining wall.
2.2.8 Construction of Structure
As noted above, the structure can be constructed in a ‘green field’ site, so there is
considerable flexibility in the construction sequencing. In order to eliminate the risks of
working at height, ‘top down’ construction will be used. An outline sequence for the
structure is as follows:
Remove any soft areas in the existing made ground.
Fill the location of the deck with structural backfill up to bridge soffit levels.
Construct temporary piling platform for Ineos Chlor and Equestrian Bridge abutments.
Install Ineos Chlor retaining wall.
Install bridge abutment piles.
Construct bridge deck.
Carry out the bulk excavation for the link road cutting.
Excavate below the bridge deck down to road finish level.
Install wall facing construct capping beam.
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 5 12 MARCH 2015
Construct new bridleway route.
Figure 2 Equestrian Bridge
2.2.9 Section 7 also includes the retention of the following existing structures: Rocksavage
Viaduct and Rocksavage West Bridge. These structures are identified in Scheme Road
Layout (sheet 25) - MER-DJV-DRA-HWY-07-301125 rev02. However, a section of
Rocksavage West Bridge is also demolished once the new Western Point Expressway to
Western Link North bound is completed. This existing structure will require careful and
controlled demolition as part of the removal of the existing link road.
2.2.10 Demolition of this and other existing bridge structures on the whole scheme will be
covered in a specific Demolition of Structures CMR and will be issued at a later date.
3 Site Access
3.1.1 Site access will be from the existing carriageway. Safe entry and egress from the working
areas is incorporated into the traffic management regime.
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 6 12 MARCH 2015
4 Site Clearance
4.1.1 Site clearance will be required before starting the construction works. The site clearance
is detailed on drawing MER-DJV-DRA-HWY-07-302011 rev03.
4.1.2 At Weston Link Junction there will be a need to demolish part of the Rocksavage West
Bridge.
5 Utilities Diversions
5.1.1 There are a number of existing services in the area which will require diverting or
protection during the work. Details for the Ineos Chlor Retaining Wall services protection
can be found in a separate report. (Ineos Retaining Wall Services Protection Report -
MER-CJV-CAL-TMP-07-520388 rev-)
5.1.2 A United Utilities asset, consisting of a 24’’ diameter clean water main must be diverted
due to the re-alignment of the existing junction. A suitable diversion has been agreed with
United Utilities.
5.1.3 There is an existing 18” diameter brine main serving the Ineos Chlor site. Suitable
protection, if required, will be agreed with Ineos Chlor.
5.1.4 There is an existing 500mm (nominal) diameter National Grid high pressure gas pipeline.
The retaining wall has been designed such that National Grid’s requirement for a minimum
3m space between the wall and the pipe is maintained. Vibration from our operations will
be monitored and recorded to ensure National Grid’s limit of 75 mm/s is not exceeded.
6 Construction Vehicles and Numbers
6.1.1 The execution of the Section 7 works will involve a number of wagon movements for both
delivery of materials and plant as well as removal of surplus spoil. This will include
materials to construct the retaining wall comprising:
6.1.2 Approximately 66 HGV material deliveries movements: 2 HGV for drainage materials, 40
concrete mixer trucks for pile installation, 1 HGV for hangers, 3 HGV for scaffolding, 8
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 7 12 MARCH 2015
trucks for formwork materials, 10 HGV for bent reinforcement, 2 HGV for barriers and
finishings.
6.1.3 Approximately 75 tipper HGV movements will be required for the delivery and collection
of the following plant: 2 compaction equipment (15Tn), 2 piling equipment, 2 excavators,
1 working platforms, 2 cranes, and 5 concrete pump. Approximately 10 vehicle
movements will be required for the delivery and collection of small plant and machinery
not covered above.
6.1.4 For general earthworks there will be 2 excavators, 4 dumpers and approximately 500 HGV
wagon movements for the removal of surplus spoil to adjacent fill areas within the project
boundary.
6.1.5 This section will require a workforce of approximately 35 operatives for the construction
of the infrastructure, the operation to construct the equestrian bridge in its final position
and finishing works. In addition four teams of workers will be needed for the assembly of
the general infrastructure.
6.1.6 A self-contained welfare unit will be provided within the site boundary for occasional use.
Main welfare and messing facilities will be sited at the Vencroft site off Astmoor Road. The
workforce will be bussed to the worksite at the start and finish of work and at main break
times.
7 Traffic Management
7.1.1 The construction of Section 7 works will require the closure of the existing slip roads and
main carriageway in a phased and planned manner. Convenient diversion routes to
facilitate the closures have been identified and agreed with the Traffic Manager. A strategy
has been developed to ensure that the road user will not be required to divert from their
route more than once in any direction of travel. This will ensure that traffic management
arrangements in adjacent sections do not conflict.
7.1.2 To construct the retaining wall and equestrian bridge, the earthworks material in the
existing embankments will need to be excavated and re-used in fill areas on the south
side of the river.
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 8 12 MARCH 2015
7.1.3 During installation of the piled retaining wall it is required to close the Weston Point
Expressway eastbound off-slip toward the Weston Link in Phase 1, to provide working
space. Phase 2 will require full closure of the Weston Link eastbound off-slip toward
Rocksavage Expressway with a diversion for vehicles travelling toward the M56 using a
new signalised junction at Rocksavage Way. This same diversion will be retained during
Phase 3 works. Phase 4 works will only require single lane closures on the Rocksavage
Expressway. These plans will be agreed through the Traffic Management Group within
the agreed timescales.
7.1.4 Some incidental localised Traffic Management may be required as the works progress in
Phase 1, for such works as service diversions. These TM layouts will be agreed with the
Traffic Manager. All notice periods will be adhered to for the approval of such works.
7.1.5 Pedestrian Management – To construct Phase 1 and 2 of the works the equestrian
bridleway/footpath will have to be temporarily closed since there is no viable alternative
diversionary route. Any other localised temporary diversions of the footpaths will be
surfaced, well maintained with signage and segregation barriers in place. Any diversion
length will be kept to a minimum whilst ensuring the safety of pedestrians is maintained
at all times. These, too, will be agreed with HBC highways authority in advance.
Construction plant and pedestrians will be segregated at all times and warning signage
displayed at all crossing points. Advance notices will be issued for any closure and will
be planned in advance if required later in the construction period.
8 Environmental Issues
8.1 Construction Environmental Management Plan
8.1.1 Environmental issues relating to the work in Section 7 are addressed in the individual
CEMP documents previously submitted to the local planning authority. The following
Management Plans are relevant to the construction activities identified.
Pollution Prevention including Traffic Management and Water Quality
Waste
Biodiversity, (particularly Eco 8 Great Crested Newts)
Noise and Vibration
Air Quality
-
Construction Method Report Section 7 – Weston Link
MER-CJV-REP-TMP-07-510131 9 12 MARCH 2015
Appendix A – Support Documents
General
Site Clearance - MER-DJV-DRA-HWY-07-302011 rev03
Retaining wall
Ineos Chlor Retaining Wall – GA Sheet (1 of 3) - MER-DJV-DRA-STR-07-349101 rev07
Ineos Chlor Retaining Wall – GA Sheet (2 of 3) - MER-DJV-DRA-STR-07-349102 rev06
Ineos Chlor Retaining Wall – GA Sheet (3 of 3) - MER-DJV-DRA-STR-07-349103 rev04
Equestrian Bridge
Equestrian Bridge Abutment Details - MER-DJV-DRA-STR-07-346310 rev03
Equestrian Bridge GA (sheet 1 of 2) - MER-DJV-DRA-STR-07-346101 rev06
Equestrian Bridge GA (sheet 2 of 2) - MER-DJV-DRA-STR-07-346102 rev05
Traffic Management
Section 7 TM Phase 1 - MER-CJV-DRA-TRA-07-501336 rev-
Section 7 TM Phase 2 - MER-CJV-DRA-TRA-07-501337 rev-
Section 7 TM Phase 3 - MER-CJV-DRA-TRA-07-501338 rev-
Section 7 TM Phase 4 - MER-CJV-DRA-TRA-07-501339 rev-
Weston Point Diversion - MER-CJV-DRA-TMP-07-980712 rev-
Weston Point Diversion Junction Details - MER-CJV-DRA-TMP-07-980711 rev-
Services Protection Report
Ineos Retaining Wall Services Protection Report - MER-CJV-CAL-TMP-07-520388 rev-