For the widening of the M1 motorway, a flexible pavement road construction will be used.
The materials used in the surface course to assist with noise reduction will consist of a bituminous mixture of bitumen and pervious macadam (porous asphalt).Flexible road construction has been selected rather than rigid for the following reasons:Congestion, Construction & Maintenance* Flexible pavements can be quickly constructed and maintained, where rigid pavements require frequent joint maintenance.* They can also be maintained a lane at a time or with short-term road closures* Therefore, flexible pavements reduce congestion during maintenance and construction(Hunter, 1994)Reflection* Open graded asphalts particularly offer significant reductions in road surface glare and assist in making line markings stand out in contrast to the road.
(Hunter, 1994)Environmental Impact* The bitumen used in flexible pavements does not release greenhouse gas* The material used in flexible pavements may be reused and recycled.
There is no recycling of rigid pavement, it has to be hauled off and dumped somewhere.
* When the wearing course begins deteriorate, this layer can be removed and returned to an asphalt plant and combined with new material to be used in another road project* The production methods applied to make asphalt considerably reduce the energy used(Garber and Hoel, (2009)Road Safety* Open graded asphalt provides pathways for water to run-off, minimising the amount of water between the tyre and road, increasing road safety in the wetNoise* Low noise asphalt surfaces can result in a reduction in noise equivalent to halving the traffic volume or reducing the traffic speed by 25%* An overlay can be applied on an existing road surface; however, the noise absorbing properties of specially designed asphalt remain effectively undiminished over time. Hunter, N (1994)Structural Properties* Flexible pavement adjusts to limited differential settlement, however rigid pavements may fault at transverse joints* Non-skid properties do not deteriorate, where rigid pavements may lose non-skid surface with time* Tolerates a greater range of temperatures* Easily repaired – the overlying asphalt can be easily removed and then recycled to become the new cover.* If a rigid pavement does fail the implications are concerning.
For instance, the failures take the form of rigid steps in the road grade. Each section “floats” like a boat above the sub grade and tries to level itself rather than maintain the original slope. Once the alignment gets unlocked between sections there is no repair. Sometimes 5 to 10 miles of roadway has to be completely removed.
(Garber and Hoel, (2009)Noise ReductionNoise reduction does not solely rely on having noise reduction materials in the wearing course. It is essential to identify the most common factor of noise generation and then give this priority.Speed of vehicles is one of the most common factors that generate road noise. Therefore, an alternative, if possible, is to reduce the speed of traffic in urban situations to gain a considerable benefit at little cost.
The materials used in the wearing course can also assist in reducing noise, as some materials may generate less tire noise than other surface materials. The materials used in this scheme to reduce tire-generated noise will consist of a bituminous mixture of bitumen and pervious macadam (porous asphalt). The main advantage of pervious macadam’s is a reduction in road noise when compared with a conventional bituminous or concrete running surface. These ‘quieter’ road surfacing materials are defined as those providing a minimum noise reduction of 3.
5dBA when compared to Hot Rolled Asphalt surfacing. Porous asphalt material provides a surfacing approximately 3dBA quieter than a standard Hot Rolled Asphalt surfacing, with even greater reductions in wet weather. This is a significant and perceptible reduction in noise. (Hunter, 1994)Sustainable urban drainage (SUDS)SUDS is an innovative concept which includes environmental and social factors which considering the drainage of roads.
When considering how the drainage system is going to be constructed it looks at quantity of runoff, and the amenity value of surface water in the urban environment (CIRIA, 2005).Due to the research undertaken by this paper is has been decided that an SUDS systems will be used which incorporates a underground pipe system that allows water drained through a kerb which acts as a filtration system that lets water enter a pipe which then is carried away to a pond or basin. Therefore SUDS is better suited for the drainage of the motorway rather than a conventionally designed drainage system. A justification of the choice has been given below;* SUDS controls run-off rates and volumes of water which decreases the risk of downstream flooding.
* SUDS take into consideration the long term impact that the system will have the surrounding and aquatic environment where as conventionally designed manholes system drain water for the short term which means the quality of water may be not be assured.* SUDS reducing pollutants concentrations with the water which protects the downstream water bodies which as the conventional methods allow pollutants to mix with the water.* Encourages the appropriate storage of water within basins or ponds which enhances amenity and aesthetic value of developed areas whereas conventional systems are tend to flood when capacity is too large to handle.* The man made storage places for the water or natural storage places increase biodiversity and it provides habits for wild life which is an environmental benefit.
The reason why SUDS manage rainwater better than conventional systems is listed below;* It deals with runoff at the source* Its manages the potential hazards to the quality of the water at its sourceMaintenance* It important no component of SUDS is allowed to erode because erosion will reduce the systems effectiveness* The maintenance of SUDS will be undertaken by the SUDS approving body in regards to motorways* Sediment entrapment facilities will be required to reduce sediment discharges* Once SUDS is damaged it will cost more to repair compared to a conventional manhole system and weak areas such as grass will be vulnerable to cars stopping on them.Case studyA SUDS system was utilised at Hipwood motorway service area which contributed to various drainage benefits to the service station and these same benefits can be utilised if a SUDS system is appropriately designed for motorway project. Benefits include;* Control of water volumes to an offsite basin where as in a conventionally designed system there is chance of overflow and flooding.* Cost of maintenance reduced compared to a conventionally design man hole system* Robust and can withstand high winds and damage.
(Bay, R, 2003)Planning and developmentResulting floods during 2007 the government commissioned an investigation and the Pitts report which endorsed the Flood and Water Management act. The act cover various areas such as water resources, reservoir safety, which means the SUDS system which should be incorporated for the motorway drainage, will have to comply with this act and there may be other legislation for SUDS in the future which DEFRA suggests (Roberts, 2011).Conditions of act;* Approval must be given for the SUDS by the SAB (SUDS approving body)DEFRA. (2010).
ReferencesBay, R. (2003). Hopwood Motorway Service Area, M42 Junction 2, Near Bromsgrove. Available: http://www.
Last accessed 2/03/2011.DEFRA. (2010). What does the Flood and Water Management Act.
pdf. Last accessed 2/03/2011.HSI. (2009).
Project applications. Available: http://hsi-engineering.com/project_appl/pavements/index.html.
Last accessed 26/02/2010.Hunter, N (1994) Bituminous mixtures in road construction, London: Thomas TelfordGarber, N and Hoel, L (2009). Traffic and highway engineering. 4th ed.
USA: Thomson West. 1076-1078.O’Flaherty, C.A (2002) Highways the location, design, construction and maintenance of road pavements, 4th edition, Oxford: Butterworth – HeinemannRoberts, M.
(2011). Flood and Water Management Act, 2010. Available: http://www.mortonroberts.
com/flood%20and%20water%20management%20act.html. Last accessed 3/03/2011.Method statementsPRELIMINAIRIESMethod statementMETHOD STATEMENT NO.
1OperationSite set up and traffic management arrangementsDuration2 days for each phase.Details of WorkSite Set Upa) Works include setting up site for works to proceed. Such as establishing compounds and facilities including site accommodation. Site accommodation to be set up according to contractors requirements.
Traffic ManagementTraffic Management items involve the following sequence of works each section at a time (mainly which will be carried out during night hours):a) Set up speed enforcement cameras involving full cooperation with local Police for appropriate requirements.b) Install temporary CCTV systems to provide swift identification of incidents and help to reach vehicles if they break down.c) If vehicles breakdown they will be taken to recovery vehicle sites. Therefore, recovery vehicle sites are required to be established.
d) For each section set up and remove barriers and erect temporary signs.e) Following this, the existing hard shoulder and lane 1 will be closed to erect a temporary steel barrier in the middle of lane 1 to separate the workforce from traffic. Steel barrier to be installed according to manufacturer’s requirements.f) The procedure for erecting a temporary steel barrier will also be implemented for works on the central reserve, to separate the workforce from traffic.
PlantSite Vans 360 Degree Mini DiggersForklifts Dumpers7.5t Beavertail Lorries CompressorsLabour1 ganger1 skilled operative2 unskilled operatives2 plant operatorsHealth and Safety HazardDeaths/injuries arising as a result of live traffic entering the workspace or construction activity interfering with live traffic.Risk Control Measurea) Suitable barrier to be used to protect workforceb) Traffic management scheme to provide maximum working space.c) Subcontractors to be fully inducted by Main Contractor/ Operator before working near live or site traffic.
SITE CLEARANCEMethod statementMETHOD STATEMENT NO. 2OperationSite ClearanceDuration2 days for each phase.Details of WorkGeneral site clearance has been quantified based on a typical verge to verge width of 45m.a) This will cover for the removal of existing superficial items of motorway furniture.
b) Areas of vegetation that need to be cleared followed by removal of topsoil, which will be deposited in spoil heaps ready for re-use in finishing off the verges and similar features immediately prior to completion.c) Topsoil will be one such material that is separated into spoil heaps for finishing off embankments and general areas to be grassed.d) Other items that need to be cleared include safety fences, motorway signs, existing communication cables, traffic signs and lighting columns.e) Lighting columns include: central reserve mounted steel lighting columns and luminaires, verge mounted steel lighting columns and luminaires and also removing lighting cables.
PlantSite Vans4 tonne dumper7.5t Beavertail LorriesCompressorsTractor loader20 tonne mobile craneLabour1 ganger1 skilled operative2 unskilled operatives2 plant operatorsHealth and Safety HazardDeath/illness/injury caused by damaging existing utilities during site investigations/ construction worksRisk Control Measurea) Design works to avoid utilities where possibleb) Divert utilities before works commencec) Notes to be added to drawing warning of risks.TRAFFIC SIGNS ; ROAD MARKINGSMethod statementMETHOD STATEMENT NO. 3OperationRemoval of traffic signs and works to change road marking and road studsDuration1 day for each phaseDetails of WorkTo reduce the amount of extra land required for the new lane, it has been assumed all motorway lanes will be narrowed.
It has also been assumed that all motorway lines, markings and studs will need to be replaced.Line RemovalThe machinery used is a skid steer loader fitted with a hydraulically powered planning head. To ensure good output the traffic management should be so organised to create suitable sections of work. The machines head is set to remove the markings without damaging the road surface.
In some circumstances, it may be required to remove the remainder of the marking that is left in the voids of the surface with a HCA lance.The debris from the above removal methods will be removed by either hand sweeping for small amounts or mechanical sweeper for larger volumes.Road MarkingIn cases where road marking material is applied from a slow moving vehicle, it will not normally be practical to lay out fixed signs at the roadside, other than at the start and finish of the restricted length of road. Instead the application vehicle, and any other vehicle travelling in convoy with it, will be fitted with warning signs and amber warning light systems, which will operate at all times during the work progress.
Work being carried out using the above system will normally occur during good visibility and periods of low risk.Road Stud InstallationBecause of the more static nature of this operation the traffic control measures will be carefully assessed taking into account, traffic speeds and flows, visibility, carriageway width and location of hazards such as junctions.Traffic SignsIt has been assumed that the existing traffic signs on the motorway would need to be replaced, but the signs at junctions approaching the motorway would remain unaffected.PlantSkid steer loader JCB 3CXSite Vans 125 cfm compressorRoad marking vehicle 8 tonne lorry with hiab liftLabour1 ganger 1 skilled operative2 unskilled operatives 2 plant operativesHealth and Safety HazardDeaths/injuries caused by reducing the width of lanes through road worksRisk Control Measurea) Aim to simplify T.
M. phasing ; hence usability for driversb) Consider reduction in speed limitsENVIRONMENTAL BARRIERSMethod statementMETHOD STATEMENT NO. 4OperationWorks to existing and new environmental barriers (noise fences)Duration1 day for each phaseDetails of WorkWorks on environmental barriers will include both erecting new noise barriers and works to existing noise barriers. Noise barriers involve both absorptive and reflective barriers.
Installing new barriersa) Erecting new sound absorbing noise barrier systems shall be installed per the manufactures recommendations to the lines and grades shown in the contract documents or otherwise specified.b) Install panels to the elevations shown in the contract plans or layout drawings.c) Lifting shall be used to lift noise fences.d) Lift and lower panels into the post flanges making sure the panels absorptive or reflective side is facing the noise source.
Existing barriersWorks on existing environmental barriers will include increasing the height of a selection of existing barriers. The locations and types of environmental barriers (noise fences) that are envisaged are indicated in the Noise Barrier schedule contained in the Contractors Design Submission.PlantSite vansAgriculture type tractorDrop side trailer, two axlesLabour1 ganger1 skilled operative1 unskilled operatives1 plant operatorHealth and Safety HazardDeath/ injuries caused by accident when plant enters/ leaves site duringconstruction period.Risk Control Measurea) Reduce the number of access/egress points if possible,b) Consider reduction in speed limits/ and additionalc) Provide awareness training for staff/ drivers/ additionalsigning, consider batching material deliveriesEXCAVATIONMethod statementMETHOD STATEMENT NO.
5OperationExcavating materialDuration1 week per phaseDetails of Worka) Works will involve excavation to widen existing cutting slopes or fill to widen existing embankment slopesb) The existing hard shoulder will also require excavation and disposal of the existing pavement. A provision will also need to be made of a 600mm capping layer for a new motorway pavement.c) Excavation will also take place at side road crossings. An assessment has been made of the bulk excavation and fill requirements at side road crossings where existing over bridges are being replaced.
In general, all excavated materials (other than topsoil) has been assumed to be unacceptable for use as fill, and all fill materials have been assumed to be imported materials.Methoda) The method of excavation will involve full depth, full length excavation. This method involves excavating plant to complete the excavation non-stop ahead of any other operation.b) The works for excavation will be carried out by excavating plant, which first will strip the topsoil for re-use and then reduce the level of the ground to the required formation level.
c) The cutting is to be taken out using a combination of motor scrapers push-loaded with a tracked dozer.d) This material will then be picked up by a 40 tonne 360 tracked excavators which will load material into articulated dump trucks to take off site.e) The immediate removal of spoil from site will involve the control of lorries to allow maximum utilisation of excavating plant.f) Consideration must be given to spillage of soil when leaving the site, traffic flowing lanes must be kept clean at all times.
Plant3 No. Terex TS24 motor scrapers 1 No. Cat D7 dozer (pushing)1 No. Akerman H10 excavator 1 No.
Komatsu PC380 excavator3 No. Cat D400 dumpersLabourExcavation gang:1 Banksman1 Foreman3 plant operatorsHealth and Safety HazardCongested area in which plant operates – chance of crushing injuries due to turning and reversing pantRisk Control MeasureProvide banksman and detailed method specificationDRAINAGE SUDSMethod statementMETHOD STATEMENT NO. 6OperationDrainage SUDSDuration1 week per phaseDetails of WorkDrainage works involve replacement of the existing verge and central reserve drains. Existing carriageway cross drains are assumed to be reused within the proposed network.
PlantKomatsu PC180 tracked excavatorKomatsu WA470 wheeled loaderJCB 3CXHydraulic excavatorCompressorLabour2 gangers2 banksmen5 labourersBricklayerHealth and Safety HazardDeath/injury arising from people and/or plant falling into balancing ponds.Risk Control Measurea) Specify appropriate boundary fencing and provision of life saving rings, ropes and lanyards, including in temporary pre completion phase.b) Higher level of provision appropriate near public rights of way and built up areas.c) Contractor / maintenance staff to adopt safe systems of work.
EARTHWORKSMethod statementMETHOD STATEMENT NO. 7OperationSlope TreatmentsWidening to embankments by retaining wallsWidening to cut slopes by soil nailingDuration4 days per phaseDetails of WorkSlope treatments will involve widening to embankments by retaining walls. Retaining walls require a great deal of construction work and the scale of this can disturb those living nearby. To limit the amount of retaining walls an alternative will be used such as soil nailing, where it is possible.
Widening to embankments by retaining wallsa) This will begin with installing contiguous bored piles or sheet piles, finished with a capping beam, or spaced piles infilled with precast planks, at the top of the existing embankment slope.b) This will then be backfilled with additional fill to create the additional width, including a pedestrian handrail on the capping beam and provision for lighting columns, power/communications cabling and noise fences where required.c) All of the retaining walls will be built during the verge works, so the same specialist engineers can be used for a continuous period.Widening to cut slopes by soil nailinga) Works to begin with excavating the toe of the existing cutting slope to create a 2 in 1 face for soil nailing.
b) This will then be finished with a flexible face (mesh with topsoil infill and green facing).c) Nails up to 10 metres long are to be drilled into the earth and fixed in place with special concrete.d) The mesh will keep the topsoil in place. Vegetation will be planted on top of this.
PlantHydraulic excavatorCrawler tractorCat D400 dumpersLabourBanksmanGanger3 plant operatorsSpecialist engineersHealth and Safety HazardEmbankment widening can lead to slope failure for the following reasons: plant weight induces slope failure and excessive stockpiling of material on the embankmentRisk Control MeasureUndertake slope stability analysis to find maximum permitted crest surcharge, and then limit access to slope crest accordingly.MOTORWAY COMMUNICATIONSMethod statementMETHOD STATEMENT NO. 8OperationRemoving and installing motorway communicationsDuration4 days per phaseDetails of WorkThe details of work for motorway communications involves the following:a) Removing existing cables and equipmentb) Providing a temporary communications bypass systemc) Providing new and upgraded power suppliesd) The provision of ‘free-issue’ equipmente) A Cable Ducted System Network (including transverse ducts using trenchless techniques)f) Emergency Telephonesg) Super spanning Portal Lane Gantries (with lane indicators and EMS signs to one or both carriageways)h) MS1 entry stop signaling, MIDAS inductive loops and CCTVi) Electronic Outstation Equipment and cabinetsj) Access Steps, pathways and handrail to equipment sitesPlease note:The super spanning lightweight gantries are to be spaced for intervisibility for a future controlled motorway.The task involving upgrading power supplies and the capacity of the cable network for communications and power, allows for the possible future addition of controlled motorway equipment.
Plant15 tonne mobile craneAccess platform, Simon hoist (50 ft)125 cfm compressorJCB 3CX backhoeTrench excavatorLabourCable laying gang: Service trenching gang1 ganger 1 ganger2 skilled operatives 2 unskilled operatives1 skilled operatives 2 plant operators2 skilled operativesHealth and Safety HazardDeath/illness/injury caused by damaging existing utilities during construction worksRisk Control Measurea) Design works to avoid utilities where possibleb) Divert utilities before works commencec) Notes to be added to drawing warning of risks.PAVEMENTSMethod statementMETHOD STATEMENT NO. 9OperationAdding new lane, replacing surface course of existing hard shoulder and central reserve.Duration5 weeks per phaseDetails of WorkWhere full depth pavement has been assumed on the following construction depths:ï¿½ 150mm Type 1 sub-baseï¿½ 230mm HMB35 Baseï¿½ 50mm HMB35 Binder Courseï¿½ 35mm Type C Thin Wearing Course SystemAdded lane – new full depth flexible construction with low noise surfacingPlacing of Type 1 Sub-basea) Prior to placing any Sub-base material, the underlaying sub-grade shall be shaped and compacted in accordance to the specifications.
b) The crushed aggregate from approved sources shall be placed over the full width and to the required thickness as shown in the drawings in one layer or more, each layer not exceeding 150mm compacted thickness.c) The Sub-base shall be compacted using suitable compaction equipment approved by the Engineer to not less than 95% of the maximum dry density determined in the B.S. 1377 Compaction Test (4.
5 km rammer method).d) The top of Sub-base shall have the required thickness, shape, levels and grades as required in the drawings and shall be within the tolerances as specified in the specifications.e) In the course of the construction, the level shall be checked using control/dipping pegs, set out at regular interval along both sides of the pavement.Placing of 230mm HMB35 Road Basea) The material shall be laid using approved machineries and compacted in layers in accordance with specification.
b) Any areas of compacted material having a loose surface deficient in fines due to segregation or otherwise shall be made good by being removed and replaced with properly graded material.c) Preparation of Road base and Wet Mix Macadam shall follow previous layer procedure.d) Prior to laying, the stringline for the gradeline sensor shall be set out by the survey team at regular intervals along the sides of the carriageway and shall be set to the required levels.e) After the stringline level is jointly surveyed, the laying operations may commence.
Prior laying, foreman shall ensure that all gradeline and slope sensors are set and working properly.Placing of Surface Coursea) Preparing the existing unbound base course for the application of the Dense Bitumen Macdam 50 (DBM50). This preparation consists of (a) proof rolling to identify weak areas in the unbound base, (b) repairing the unbound base in weak areas using crushed stone, (c) further rolling to meet density requirements.b) The surface to receive the premix shall be cleaned, free from dirt, loose materials and standing water.
c) Supply and laying of prime coat/tack coat on the prepared unbound base, and allowance for a curing period.d) Supply, lay and compact DBM50 layer with a nominal maximum stone size of 50 mm to required thickness.e) Supply and apply bituminous Tack Coat prior to the laying of PERVIOUS MACADAM (POROUS ASPHALT).f) The approved premix shall be delivered to site by tipper trucks.
To prevent loss of heat, the mixture shall be covered by tarpaulin.g) Supply, lay and compact PERVIOUS MACADAM (POROUS ASPHALT) as specified thickness (35mm) including necessary regulating works. Materials and workmanship shall be as per specification.h) Supply and apply bituminous tack coat.
i) Asphaltic concrete shall not be opened to traffic until compaction has been completed and the materials has thoroughly cooled and set in the opinion of the Engineer’s representative. This is usually not less than 4 hours from the initial of rolling.Hard shoulder and central reserve- existing surface course removed and replaced with new surface course with low noise surfacingj) Milling and excavate out of the existing asphalt, road-base and unsuitable sub-grade layers to a required depth or as shown in the accompanying drawings.k) All formation and Sub-base/upper-base preparation shall be followed specification.
l) The following steps involve placing the surface course, which should proceed as explained above.PlantMotor Grader/paver Back pusher with power broomDiamond Cutter and jack hammer Milling MachineWater tanker Air compressorBituminous Tack Coat distributor Tipper lorries35 kW Asphalt paver Tandem roller & Pneumatic tire rollerRecycler Bitumen Tanker93 kW Motor Grader Pre-heaterRe-mixerLabourSub-base laying gang: Flexible paving gang: Milling gang:1 ganger 1 ganger 1 ganger1 skilled operative 2 skilled operatives 2 skilled operatives2 unskilled operatives 4 unskilled operatives 4 unskilled operative3 plant operators 5 plant operators 3 plant operatorsHealth and Safety HazardDeath/injury arising from contractors staff being struck by plant during construction/ maintenance activitiesRisk Control Measurea) Develop design to minimise the interface between workers and construction trafficb) Appropriate use of banksmenc) Ensure adequate site safety briefing prior to going on site.d) Contractor/Operator to ensure adequate site safety procedures in place and that they are fully implemented.ROAD LIGHTING COLUMNSMethod statementMETHOD STATEMENT NO.
10OperationRemoving and installing new lighting columnsDuration4 days per phaseDetails of WorkSite Clearancea) Take up or down and remove to tip off site a central reserve mounted steel lighting column and luminaireb) Take up or down and remove to tip off site a verge mounted steel lighting column and luminairec) Take up or down and remove to tip off site feeder pillar and PECU on columnd) Take up and remove to tip off site lighting cable.Road Lighting ColumnsNew motorway lighting has been assumed to the whole route, based on lighting columns placed in each verge. The following lighting columns are to be installed (please see Contractors Lighting Schedule for quantities and locations):a) New steel road lighting column of 12m or 15m nominal height with planted base and with single bracket arm having a projection of 1.5m with a full cut off luminaire incorporating a 250W or 400W SON-TP lampb) Raising and Lowering type Steel road lighting column of 12m or 15m nominal height with planted base and with single bracket arm having a projection of 1.
5m with a full cut off luminaire incorporating a 250W or 400W SON-TP lampPlant15 tonne mobile crane125 cfm compressor2 tonne dumperAccess platform, Simon hoist (50 ft)Labour1 ganger1 skilled operative2 unskilled operatives2 plant operatorsHealth and Safety HazardDeath/illness/injury caused by damaging existing utilities during construction worksRisk Control Measurea) Design works to avoid utilities where possibleb) Divert utilities before works commencec) Notes to be added to drawing warning of risks.OVER BRIDGE WORKSMethod statementMETHOD STATEMENT NO. 11OperationWorks to over bridgesDurationThroughout project periodDetails of WorkThere are 22 over bridge structures on this section of route. The scope for structures is to keep existing structures where possible with hard shoulder discontinuities.
The scope of works for over bridges will include:a) 2 over bridges being replaced onlineb) 2 Accommodation Bridges will be replaced as Footbridgesc) 1 bridge will be fully demolished.This will involve works to the Verge Piers, Central Reserve Pier and Parapet or safety fence.Verge Piers – 4 no. strengthening and 1 no.
safety fence protection.Central Reserve Pier – 2 no. strengthening and 8 no. headroom protection.
Parapet / safety fence – 2 no. parapet and safety fence upgrade.Please note:a) With the exception of box type structures, all bridges shall have parapet cantilevers that extend from the edge beams or main deck.b) Parapets on a single structure shall be of the same form.
c) Mesh infilling shall be provided on all metal parapets on road over road bridges with the exception of those structures deemed to require equestrian parapets, which shall require solid infill over a proportion of their height.d) The fixing of traffic signs or signals to parapets or bridge decks shall not be permitted.Demolition to Farm Bridgea) Will be carried out using tried and tested methods.b) Post-tensioned concrete structures will be ‘cut’ into longitudinal slices using a developed machine mounted saw.
c) The sections will then removed during overnight possessions of the motorway.d) The new steelwork will be transported in two sections and lifted into position using large mobile cranes.e) The deck will be supported initially on temporary supports.PlantAgricultural type tractor with front bucket8 tonne lorry with 1 tonne hiabHyundai ExcavatorsFront End LoadersLabourParapet gang:1 skilled operative2 unskilled operatives1 plant operatorHealth and Safety Hazarda) Death/ Injury caused by falling from heights whilst working on existing overbridges.
b) Objects falling from height during bridge constructionRisk Control Measurea) Construction method to be considered during design to reduce exposure if possible. Temp works designer to liaise with perm works designer concerning harness points/lifting points/construction method assumptionsb) Contractor to carry out risk assessments and adopt safe working methods (such as the use of protective netting, etc).UNDER BRIDGE WORKSMethod statementMETHOD STATEMENT NO. 12OperationWorks to under bridgesDurationThroughout project period.
Details of WorkThere are 23 under bridge structures on this section of route. The scope for structures is to keep existing structures where possible with hard shoulder discontinuities.The method of construction for under bridges will involve symmetrical widening of 13 under bridges.This will involve works with Headwall provision, Parapet upgrade and Deck edge strengthening.
a) Headwall provision – 2 no. to act as retaining structure and parapet upstandb) Parapet upgrade – 4 No. (railway bridge) with high containment and 3 No with normal containmentc) Deck edge Strengthening – 1 No. (‘Preflex’).
This will involve strengthening by over slabbing.Care is to be taken to ensure the new extensions do not impart additional load to the existing structures.PlantAgricultural type tractor with front bucket8 tonne lorryFront End LoadersLabourParapet gang:1 skilled operative2 unskilled operatives1 plant operatorHealth and Safety Hazardc) Death/ Injury caused by falling from heights whilst working on existing under bridges.d) Objects falling from height during bridge constructionRisk Control Measurec) Construction method to be considered during design to reduce exposure if possible.
Temp works designer to liaise with perm works designer concerning harness points/lifting points/construction method assumptionsd) Contractor to carry out risk assessments and adopt safe working methods (such as the use of protective netting, etc.).e) Contractor to provide appropriate protection barriers.SAFETY BARRIERSMethod statementMETHOD STATEMENT NO.
13OperationWorks to central reserve barrierDuration2 days per phaseDetails of WorkWhere required, the site will be mobilised and the appropriate Traffic Management will be installed by others. No works are to commence until the Traffic Management is set out correctly. The work will be carried out under lane closures with clearly marked works entry and exit points.No works are to commence until a permit to work / dig have been issued by the MainContractor clearly identifying all services.Any underground services are to be identified to the operatives and their positions clearly marked.Removal of existing Vehicle Safety Barrier.a) Check with Site Manager whether taken down materials are to be re erect on the project, or if they are to be removed off site.b) From agreed locations, remove existing Lap bolts and post bolts using air tools.c) Stack beams on Side Loader Forklift and take to agreed storage area on site.d) Open Box Beam are to have a minimum of 2 No metal bands placed around each stack prior to being loaded onto transport for removal from site.e) On completion of take down of existing safety fencing, transport will be arranged to attend site to remove all beams.f) Transport to be loaded by forklift truck with aid of competent banksman positioned to the satisfaction of the lorry driver.Installation of new central reserve concrete barriera) Materials are to be delivered to site at times agreed between the Contract Manager, the buyer, and the supplier, so as to reduce disruption whilst on site activities are being carried out.b) Concrete is to be laid and embedded into the central reserve pavement constructionc) The new vertical concrete barrier has been assumed for the full length of the central reserved) A Higher Vertical Concrete Barrier has been assumed for the motorway verges through Trowell MSA to replace the existing VCBs.PlantSite Vans 360 Degree Mini DiggersForklifts 7.5t Beavertail LorriesCompressors Agriculture type tractorDrop side trailer, two axlesLabourBanksman 1 ganger1 skilled operative 2 unskilled operatives3 plant operatorsHealth and Safety HazardDeaths/injuries arising as a result of live traffic entering the workspace or construction activity interfering with live traffic.Risk Control Measurea) Reduce hazard by increasing space between construction activity and live trafficb) Suitable barrier to be used to protect workforcec) Subcontractors to be fully inducted by Main Contractor/ Operator before working near live or site traffic.
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