DENVER CONSTRUCTION SERVICES

Case Studies

Denver Construction Services offer a wide range of specialist services to the construction industry, and both private and public sector clientel. Below is a list of varied project types undertaken by Denver Construction Services.

Project Name: Ford Engine Plant

Location Area : Bridgend, S.Wales
Contract Duration : 12 months
Type Of Work: Diamond Floor Sawing
Value : £150,00.00

The Ford Factory in Bridgend had been at the forefront of car engine building for over 30 years. To plan for future expansion and development, Ford decided to modernise parts of the plant by installing new machinery with the latest technology.

One of the problems faced by Fords was that the weight of new machinery was too heavy for the existing factory floor slab at the installation areas.

It was decided that the existing 300mm thick reinforced concrete floor slab would have to be cut and removed with a stronger slab constructed on completion. There were approx 6No areas approx 400 mtrs x 400 mtrs square which needed to be removed.

Denver Construction supplied 2No large 65Hp diesel diamond floor saws to cut up each of the 400mtr square openings into 1.0 mtr square blocks x 300mm depth. Each block was then lifted out and removed by telescopic forklifts.

During the programme of works Denver Construction Services carried out over 7000 lin-mtrs of saw cutting, and by the end of March 2005 the project had been successfully completed on schedule.

Project Name: Holland House Hotel

Location Area: Newport Road, Cardiff
Contract Duration: 7 months
Type Of Work: Controlled Demolition, Diamond Sawing, Diamond Drilling
Value: £150,000.00

The Holland House Hotel project was a massive alteration and refurbishment project on an existing 16 storey concrete framed structure acquired from the Chartered trust Group.

A major alteration for the new hotel was the total demolition of an existing 2 storey extension structure which consisted of heavily reinforced concrete walls, huge concrete panels and 800mm thick reinforced support beams and upright columns.

The 2 storey extension itself was approx 30.0 mtrs x 15.0 mtrs square and was built on top of an existing basement car park area. With this in mind the main contractor faced a massive demolition problem with a 1.5 ton weight restriction applicable on the ground floor slab. Additional logistical problems faced by the main contractor were the close proximity of main roads and neighbouring office buildings.

To overcome all these logistical problems Denver Construction Services were consulted and awarded the demolition contract which was to be undertaken with the use of diamond cutting methods and Brokk Robotic machine demolition techniques.

Diamond floor saws and track wall saws were used to detach the 2 storey extension from the main building and hydraulic bursters were used to break up the 800mm thick support beams and columns.

A Brokk 150 3 Phase Robotic demolition machine (which met the 1.5 tonne weight restriction) was then lifted up to the roof slab of the extension via craneage and then placed through a pre cut hole in roof slab onto the 1st floor area.

Complete with crunching jaws and demolition pecker, the Brokk 150 enabled Denver Construction Services operatives to successfully demolish the entire building extension area within the required contract period time.

The success of this project led to further phases of the project being awarded to Denver Construction Services.

Project Name: Millenium Stadium Project

Location Area: Cardiff, S.Wales
Contract Duration: 2 years
Type Of Work:, Diamond Cutting and Demolition Techniques
Value: £250,000.00

Denver Construction were the first specialist contractor to undertake work on the magnificent Millenium Stadium Project after the old Cardiff Arms Park demolition had been completed. During the building of the new stadium, at its peak period, Denver Construction Services had 10No drilling and sawing operatives working around the clock undertaking diamond drilling, diamond floor sawing, diamond wall sawing, hydraulic crunching and bursting and wire sawing projects.

Denver Construction Services worked continuously throughout the project and were still drilling barrier post holes on the day of the opening match.

Project Name: Neo Natal Roof Extension

Location Area: University Hospital of Wales, Cardiff
Contract Duration: 3 months
Type Of Work: 3 Phase Hydraulic Bursting and Crunching/ Controlled Demolition
Value: £50,000.00

When the contract to build an extension on top of the existing neo Natal building roof was awarded to the main contractor, part of the package was to demolish all the heavily reinforced roof perimeter dwarf walls and reinforced concrete roof plinth upstands.

One of the logistical nightmares facing the main contractor was the immediate location of the premature baby incubation units beneath the roof slab which supported the plinths and dwarf walls. Stringent restrictions meant that no water could be allowed to leak through the roof slab and so diamond core drilling and wall sawing were not an option.

Having been approached, Denver Construction services decided to demolish the walls and plinths using controlled hand held hydraulic crunchers and bursters. The use of this equipment meant that the entire ongoing operation was carried out with minimum noise levels, and no water requirements, making it the perfect solution to the prohibitive requirements implemented.

Again the job was completed within the time scale allocated, to the delight of the local Health Authority.

Project Name: The Trocadero

Location Area: Piccadilly Circus, London
Contract Duration: 2 months
Type Of Work: Diamond Stitch Drilling – Piling Foundations
Value: £80,000.00

A major part of the foundation strengthening to the Trocedero Project, was the requirement for piled foundations in the access restricted basement area. Piling rigs were to bore 500mm diameter piles in restricted areas to required finished depths.

A major problem to the project was that during drilling depth investigation the basement floor slab was found to be up to 4.0 mtrs in depth. This meant that a requirement of drilling 600mm diameter holes in seawash reinforced aggregate concrete to depths up to 4.0 mtrs would be required.

After advising the client Denver Construction Services were awarded the contract to drill the piling foundation holes.

Denver Construction Services decided to use 100mm diameter barrels x 4.0 mtrs long to stitch drill a circular series of holes to form the 600mm diameter openings required. When each of the 4.0 mtr x 100mm diameter cores had been extracted and removed the remaining reinforced concrete section approx 500mm diameter x 4.0 mtr length had to be lifted out.

To achieve this Denver Construction Services drilled and fixed high strength resin lifting lifting eye anchors into each section and lifted each one out with the use of hydraulic chain lifting blocks bolted through the ground floor slab ceiling.

Denver Construction operatives worked continual 24 hour shifts throughout the contract and successfully completed the job ahead of schedule.

Project Name: Project Pegasus

Location Area: London Airport, Luton
Contract Duration: 4 months
Type Of Work: CFA Piling and Mini Piling
120 No 250mm Diameter Sectional Auger Piles to 10.0 mtrs
240 No 300mm Diameter Sectional Auger Piles to 12.0 mtrs
80 No 450mm diameter CFA piles to 16.0 mtrs
Value: £450,000.00

Project Pegasus was the expansion and development of both existing internal and new external areas at London Luton Airport to accommodate a new departure and arrival lounge area, new immigration area, and a new shopping precinct.

The design of the new building areas required additional support to the existing foundations and so after studying the information provided on ground conditions, Denver Construction Services designed a pile solution to not only accommodate ground strata but also accommodate logistical airport restrictions.

The main restrictions were the close proximity of the pile locations to the working airport, noise levels, height restrictions and confined space areas. With this in mind Denver Construction Services opted to install sectional augered mini piles and continuous flight auger (CFA) piles as both systems are non percussive piling methods that generate a minimum amount of ground borne vibration and noise.

The piles designed by Denver Construction Services were 250mm diameter, 300mm diameter and 450mm diameter with compressive loads up to 250 kn (mini piles) and 750 kn (CFA Piles).

Additonal logistical problems facing the project were the miles of electrical cables, fibre optics, and service / drainage ducts that lay at assumed depths below the existing reinforced concrete airport slab areas. To overcome the disastrous consequences of drilling into any live airport services, it was decided that each pile cap location (consisting of 4-8 piles) would be carefully excavated to locate services, and then large diameter ducting pipe would be installed to eventually auger through on completion of backfilling to finished levels.

Each pile cap area was approximately 4.0 mtrs square with hard seawash aggregate reinforced concrete floor areas above each location. To negate the use of high noise level demolition hammers, Denver Construction Services were given the task of Diamond Floor Saw Cutting the reinforced concrete foundation pile cap areas with each cap area cut into approx 20 No sections, which in turn were carefully lifted and removed from site prior to excavation works.

To accommodate both the height and access restrictions associated with the project, Denver Construction Services decided to use its TD 610W mini piling hydraulic rig which although compact in size is actually more powerful than many larger rigs twice its size. The rig itself was designed to drill holes up to 500mm diameter and with its 100mm diameter hollow main shaft in the rotation head allowing concrete to be pumped directly to the bottom of the hole if required, it made the TD 610W rig the ideal machine for CFA and mini pile drilling.

Prior to commencement of augered drilling works it had been assumed by information provided, that the ground conditions would consist mainly of clays and chalk. However during auger piling a very hard flint was found to be present throughout the ground strata.

The flint itself was so hard that conventional lead auger shoes were unable to penetrate the strata without causing auger damage.

To overcome this problem Denver Construction Services had special Rock Ripper Lead Augers with Tungsten Picks manufactured which enabled them to successfully drill through the hard flint strata and onto the pile depth required.

After drilling, one of the major additional problems facing Denver Construction Services was the concrete infill construction of the piles. Because of height and access restrictions Denver Construction Services had to use high pressure concrete pumps and tankers to pump concrete to distances ranging from 25.0 mtrs up to 50 mtrs with roof access sometimes the only viable solution.

Throughout the project, Denver Construction Services engineers carried out Simbat Dynamic Load testing, Integrity testing and concrete cube testing on specified piles as instructed by the main contractor.

Denver Construction operatives worked 7 days a week throughout the contract, and on completion a total of 440 CFA/mini piles had been constructed. The Denver Construction Services workforce was managed by a full time supervisor and a substantial contract management presence which ensured excellent communication between the airport, client, main contractor, and the Denver workforce.

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