Buckinghamshire ENERGY FROM WASTE FACILITY · facilities for Main Contract Package Contractors. The accommodation will provide compliance with all ... specialist equipment to minimise

Buckinghamshire

Contractor’s Proposals

ENERGY FROM WASTE FACILITY

SECTION 3.0. CONSTRUCTION METHODOLOGY

SECTIO

N 3.0

Buckinghamshire Energy from Waste Facility

Section 3.0 | Page 1 of 14

3.0 Construction Methodology Statement

These notes are to be read in conjunction with our tender construction programme and our construction phasing and logistics sketches, which outline the sequence of construction for the main work elements. These notes are intended to amplify and explain the logic and key methods used to achieve the successful completion of the project.

3.1 Site Logistics

The main principles of site access, temporary accommodation and logistics for the main construction phase are shown on our attached site logistics sketch.

Temporary accommodation will be erected as soon as possible after award of contract. Initially we will provide temporary welfare facilities for establishing the main accommodation and for the enabling works. This may be possible in the existing Upper Greatmoor Farm buildings, before they are demolished. The main accommodation will provide for our management team, site personnel and for the Hitachi Zosen Inova (HZI) process installation team as noted in the tender documentation. This will also include welfare facilities for Main Contract Package Contractors. The accommodation will provide compliance with all relevant welfare regulations including sanitary arrangements. Temporary accommodation units will be double stacked to save space.

Construction and visitors pedestrian access will be clearly marked to identify a safe walkway to the project and site offices, independent of site vehicular access.



3.2 Provision of Temporary Services

The following arrangements will be made for the provision of temporary services:

• Electricity supplies will be brought to the site offices and messing area from the supply established pre-contract on a sub-meter. Temporary electricity supplies to the site and lay-down areas will be installed early during the construction period, soon after the initial bulk earthworks have been carried out. The temporary site installation will reflect the requirements identified on the HZI tender schedule.

• Water supplies are assumed to be from the temporary supply established pre-contract.

• Temporary drainage facilities will be provided for the accommodation in the form of a septic tank. Whilst the tender layout indicates a drainage connection point, the infrastructure will not available for commencement of construction.

3.3 Secure Boundaries

Fencing will be installed and maintained to provide security to the main site, the temporary accommodation and the lay-down areas as follows:

• To the site boundary we will install the permanent fencing as part of the site establishment works.

• To secure the temporary accommodation and lay-down areas we will install a 2.4m high chain link fence.



3.4 Main Site Temporary Facilities

Item NotesSanitary Accommodation Toilets to be providedFirst Aid Facilities to be available in McAlpine’s offices.Sign/Notice Boards To be in accordance with the Client requirements.Sub-contractor’s Area To accommodate sub-contractors offices and storage.Scaffolding By sub-contractor except for safety purposes after sub-contract

completion.

Protection By sub-contractor except for maintenance after work package completion.

Temporary Electrical Power To feed site accommodation plus distribution boards, LV transformers and 110v socket outlets in buildings.

Temporary Lighting External lighting to main site and compounds using lighting columns; high bay safety lighting within building. Task lighting by sub-contractors.

Temporary Water Alkathene pipework to temporary accommodation and stand pipes for works.

Fire Protection Portable fire extinguishers at fire points.Refuse and Cleaning Bins and skips placed at central point with disposal at frequent intervals.Telephones Separate facilities to be arranged by sub-contractor if required. Pay phone

included in welfare facilities.

These proposals illustrate our initial thinking but our approach will of course be flexible and can be modified to suit specific client requirements.



3.5 Site Security

The site will be protected by a perimeter fence as noted above and be manned by security staff during normal working hours. The site will also be lit at night and CCTV coverage will be provided to the accommodation area. Security personnel will visit the site at irregular intervals over-night or in the event of an alarm. Later in the programme, security will be provided at all times. This will prevent unauthorised access to the site.

Access for site personnel will be via a turnstile which will be operated by either thumb print or iris scanning. Only personnel who have received a site induction and are in possession of a valid CSCS card will be given access to the site. Visitors to the site will be accompanied at all times by a person who has already been inducted.



3.6 Delivery Management

As identified in the Site Infrastructure Requirements, we will provide a manned entrance for site vehicles, deliveries and visitor reception. This will include a segregated controlled entrance for pedestrians with turnstile access as noted above.

3.7 Physical Construction

Initial Works/Site EstablishmentOnce possession of the site is granted our initial works will be to prepare for the main construction activities. This will include establishing the secure site boundary (as noted above) along with forming the main site entry and access road complete with lockable gates, temporary gatehouse and temporary wheel wash facilities. The initial works will include excavation of the ground to formation over the new building footprint.

SubstructureA temporary stone piling carpet will be installed over the building footprint, mainly just under the +0.0m level ground slabs, to provide a stable platform for the piling rig. To the bunker area the piling carpet will be installed to a level just under the concrete ring beam. Continuous Flight Auger (CFA) pile installation will commence in the waste bunker area with one piling rig with a second rig installing the contiguous piles for the tipping hall retaining wall. The rigs will then progress onto the remaining areas of the main building working from South to North.

As the piling progresses and areas become available, excavation of the pile caps and cutting down of the piles will be carried out. Excavation will generally be carried out using hydraulic excavators. Breaking down of the pile heads will be carried out using specialist equipment to minimise the need for hand work and to reduce noise and vibration. Once excavated, the base will be compacted and concrete blinded to receive reinforcement. Following concreting of the bases and removal of formwork the excavations will be backfilled and compacted.

Once the larger pile caps and bases have been constructed in each main area the underground drainage and ducts will be installed, with the drainage tested in advance of the ground floor slabs.

In order to optimise the time available for the furnace and boiler major plant installation, construction of the associated ground slabs and the bunkers need to be prioritised. As the bunkers are the deepest structures they need to be the first area built.

We have sequenced the construction of the flue gas cleaning ground level slabs to be carried out concurrently with the lower bunker walls. Also the furnace/boiler hall ground level slabs are timed to tie-in with the bunker walls once they are constructed above ground (+0.0m) level. This approach allows the furnace/boiler hall to be made available at the earliest opportunity for the major plant installation.



Excavation of the basin to construct the bunker structure below ground level will be carried out in accordance with the sequence identified on Scott Wilson drawing C2201. Initially the ring beam will be cast onto the prepared piles. Then excavation will be carried out down to -3.0m level and the temporary propping installed. The remainder of the excavation will be carried out to the base slab formation level. Materials handling to construct the base slab will largely be carried out using the tower crane. Bulk concrete placement will be carried out using lorry mounted concrete pumps.

Materials handling to construct the ground level floor slabs will be carried out using a combination of mobile craneage and all terrain fork lift. The fork lift will also be used for off-loading of materials deliveries and to distribute materials from storage areas around the site. Concrete to accessible foundations and slabs will be directly tipped into position where possible. Bulk concrete placement to non-accessible slabs, suspended slabs and walls will be carried out using mobile concrete pumps

3.8 Superstructure - Concrete Works

To minimise build-time to meet the required boiler plant installation date we propose that the main bunker and furnace hopper walls are constructed using slip-form methods. Whilst additional time is required to re-set the slip form at the +0.0m level, this method still provides the shortest overall programme.

Materials handling to construct the concrete superstructure will mainly be carried out using a rail-mounted tower crane positioned north of the proposed building (as indicated on the enclosed logistics sketch).

3.9 Superstructure - Structural Steelwork

Erection of the structural steelwork frame will commence in the tipping hall area using mobile craneage. Erection of the steelwork to the bunker area will follow, also using mobile craneage. We anticipate that the tipping hall frame needs to precede the bunker area steelwork for structural stability. Careful co-ordination will be required with the adjacent tower crane working on the boiler assembly and installation.

Erection of the remaining structural steelwork frames will also be carried out using lorry mounted mobile cranes.

The major boiler, furnace and flue gas cleaning plant installation will be carried out in advance of the building steel frame due to the equipment size and the space required for assembly. Installing the building frame after the major plant will necessitate careful design and erection of the steelwork to enable it to be installed safely, in particular the method of fixing the roof purlins to these areas.

Where possible, the use of hydraulic work platforms/cherry pickers for erection will be encouraged for safety reasons.

Hand railing and safety access scaffolding will be erected as required to ensure safe conditions are maintained.



3.10 External Envelope

Once sufficient structural steelwork has been erected the roofing and then wall cladding will be installed to enclose the building. Bulk roofing materials will be distributed using mobile craneage. Access to install the wall cladding will be provided with a combination of access platforms and fixed scaffold.

Installation of the main overhead cranes to the bunker will be co-ordinated with the roof installation so that the crane gantries can be lifted in and parked under cover.

Installation of the turbine will require a temporary structure to enable it to be installed through the external wall of the building. The building design will also need to accommodate the temporary opening in the wall.

3.11 External Works & Landscaping

Bulk earthworks will commence at the earliest opportunity in order to optimise the programme for the main building. Forming a platform over the building footprint in readiness for the temporary piling carpet will be prioritised. These initial works will include levelling the remaining areas of the site, storing the surplus excavated material in the approximate locations of the final landscape mounds. Selected fill material will be stockpiled for re-use under the tipping hall area once the bunker and retaining walls have progressed sufficiently.

Formation of the external aprons up to the underside of the concrete slabs and the base of the main access roads will be prioritised to provide stable access for construction activities and major process plant installation.

Once sufficient sections of the main structure have been completed the external drainage and ducts will be installed, with access co-ordinated to suit the ongoing process plant installation.

Formation of the surface water lagoons and final shaping of the landscape mounds will be carried out as areas become available following the heavy process plant erection.

Construction of the external concrete aprons and access roads will commence once large sections of the external envelope have been completed and following the major process plant installation.

Final trimming of the soft landscaped areas, topsoil spreading, seeding and planting will be carried out during the testing and commissioning period for the new plant.



BUCKINGHAMSHIRE EFW PLANT - CONSTRUCTION SEQUENCE & LOGISTICSMONTHS 1 TO 3

Ring beam construction ongoing

Roads constructed to top of sub-base level

Piling carpet

Piling to retaining walls & waste bunker

Bulk excavated material moved to form moundsNote: suitable fill used to commence build-up under Tipping Hall & adjacent roads

Piling

Hardstandings formed to sub-base level

Site boundary plus additional site access areas

Permenant site boundary

Topsoil stockpile

Surplus excavated material stockpile

Haul route for topsoil stockpile

Local welfare facilitiesLocal storage area

Note: Excavated material stored locally for re-use on completion

Main storage area

Car park

Main office & welfare set-up

Initial access to site

Haul route for surplus excavated material

Access to site once road extension and improvements have been carried out

Piling to retaining walls

Site compound, office & laydown area




BUCKINGHAMSHIRE EFW PLANT - CONSTRUCTION SEQUENCE & LOGISTICSMONTHS 4 TO 6

Pit excavation and base slab construction ongoing

Main Site access

Retaining walls construction

Pile caps, ground beams and underground drainage

Floor slab

Topsoil stockpile

Floor slab ongoing

SRM Tower crane on rails erected

Local welfare facilities


Main storage area

Car park


Local storage area




BUCKINGHAMSHIRE EFW PLANT - CONSTRUCTION SEQUENCE & LOGISTICS MONTHS 7 TO 10

Backfill retaining walls and construct floor slab

Erect main structure

Construct ground slabs

Area prepared for laydown

Notes: underground drainage complete andtower crane dismantled in month 10

Topsoil stockpile

Construct workshop frame and cladding

Construct transformer bases

Construct condenser bases

Sprinkler base construction ongoing


Main storage area

Car park



Install steelwork, roof slab & cladding

Construct bunker walls

Main Site access





Weightbridge civils work commence

Roof and wall installation

Infill roof slab following crane installation. Cladding installation ongoing

Fit-out ongoing

Notes: SRM tower crane dismantled prior to month 11

Topsoil stockpileSite compound, office & laydown area

Main storage area

Car park



Main Site access until permanent road is a available

Permanent site access available during this period

A3

A2

TC1

TC2

A5

A4

Storage Areas

A2 2240m2

A3 6380m2

A4 350m2

A5 3100m2

CC2CC1





Weightbridge installation complete

Install wall and roof cladding after installation of the process equipment

Fit-out complete

Construct sprinkler tanks / pumphouse

ACCs erection commences

Notes: Service apron and road construction ongoing

Topsoil stockpileSite compound, office & laydown area

Main storage area

Car park



Permanent site access

A3

A2

TC1

TC2

A5

A4

Storage Areas

A2 2240m2

A3 6380m2

A4 350m2

A5 3100m2

CC2CC1Stack erection





Complete service apron and road construction

Complete roofing and wall cladding

Complete architectural feature over ACCs Topsoil stockpileSite compound, office & laydown area

Main storage area

Car park


Permanent site access

Topsoil moved from stockpile to complete landscaped areas

Excavated material moved to form mounds

A3

Laydown area retained



BUCKINGHAMSHIRE EFW PLANT - CONSTRUCTION LOGISTICS

Additional construction only road

Roads constructed to top of sub-base level

EFW Building

Hardstandings formed to sub-base level

Site boundary plus additional site access areas

Permenant site boundary

Temporary fencing

Topsoil stockpile


Haul route for topsoil stockpile

Local storage area

Main storage area

Car parkInitial access to site

Access to site once road extension and improvements have been carried out



Traffic layby to accommodate 3/4 vehicles

Final access to site

Fence to seperate landfill construction traffic

Landfill access roadNew construction road


Tower crane on rails - 70m radius saddle jib MD 285

Haul route for surplus excavated material

Documents

Buckinghamshire ENERGY FROM WASTE FACILITY · facilities for Main Contract Package Contractors. The accommodation will provide compliance with all ... specialist equipment to minimise