whitescape civil engineering case study

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Whitescape and Civil Engineering



MORELANDS RIVERDALE BUILDINGS

CASE STUDY CIVIL ENGINEERING

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Early involvement saves time and costComplex sites or structures need bespoke strategies that are often more effectively created when the design is still evolving and all options are open. Civil engineers need to understand and align themselves with the customer’s objectives, if they are going to provide the full benefit of their specialist experience. The earlier they are involved in a project, the greater the potential for enhancing value.

Planning and collaboration are keyA successful civil engineering project depends on meticulous planning, sequencing and supervision, as well as close collaboration with architects, structural engineers and specialist consultants. The programme must also be flexibly

designed to accommodate unpredictable issues. Strong communication between all stakeholders and the supply chain will prove invaluable in guiding the project to successful completion.

Precision is the civil engineer’s bywordFine tolerances, where there’s no margin for error, demand top skills and experience. Civil engineering is a people business where every team member shares responsibility for getting design and installation exactly right. At Whitescape, we employ all our own professionals and operatives, so we can vouch for their capability and commitment. Our in-house training ensures they achieve and maintain the highest practice standards.

Civil engineering is the foundation of every successful construction project, and a major factor in maximising the commercial value to landowners, developers and investors. Complex infrastructure projects of any scale need intelligent solutions to resolve the challenges. For sites that present special technical issues, the civil engineering contribution can make a material difference to financial returns.

Specialist solutions for optimum outcomes

Morelands Riverdale: demonstrating our approachThis case study exemplifies how we delivered a complex technical requirement on a particularly difficult brownfield site. What we accomplished here illustrates our aim for all civil engineering projects: to optimise the potential of the site and its structures, and to surpass all expectations in doing so.




bordering the filter beds to provide access, parking and vital service infrastructure, without which planning consent would not have been granted. The roadway construction incorporated ground source heating and cooling, other M&E and IT services.

To optimise limited space, the new road was cantilevered over an existing embankment. This section spanned critically important underground infrastructure that forms part of the mains

The Morelands Riverdale buildings are two redundant listed Victorian water pumping stations beside the Thames at Hampton, now being converted to accommodate up to 100 scientists in startup microbiology businesses.

The Grade II buildings comprise over 400 m2, and occupy a constrained and sensitive brownfield site at one of the largest water treatment plants in Europe. The challenge was to widen a road

Complex infrastructure on a challenging site

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water supply to west London and has to remain accessible to Thames Water. Logistical operations were complicated by prohibited access to the filter beds, which are protected against contamination by high security, in place 24/7.

Whitescape designed a novel piling system to avoid all existing infrastructure and installed it to exceptionally fine tolerances. Working closely with the architects, structural engineers and drainage consultants, we maintained a carefully sequenced

programme while dealing with both known and unknown challenges on site.

This is the kind of project we relish, as it provides a real opportunity to exercise our intelligent and adaptable approach. We also appreciated being an integral part of this inspiring and ambitious project to bring historic buildings into innovative contemporary use.




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”ABOUT THE PROJECT

• 220m roadway

• Cantilevered construction

• Incorporating infrastructure services

• Historic brownfield site

• Multiple stakeholders

• 39 week timescale

• Value: £2.5m

The project has not been without significant challenges. It has not only involved a fluid design process, but also required close liaison with major utility suppliers and their network infrastructure, as well as full time co-ordination with multiple additional contractors. Whitecape, Michael and his team have continually worked through many scenarios that would have been immovable objects to others. As we reach the final stages of this road extension, I can safely say that regardless of the fact that it required many unique and bespoke processes and products, Whitescape have delivered a major contribution to our project to a high standard.

ALAN HOPLEY - Blackbottle Limited




The challenging nature of the Morelands and Riverdale site demanded exceptional precision in constructing the new road and infrastructure. Whitescape’s contribution in engineering an intricate design was fundamental to providing essential facilities and services for the buildings, as well as adequate access and parking for their occupants.

The design involved a cantilevered construction over the Thames Water embankment bordering the filter beds, to support the parking area of the road above and to protect important piping and culvert runs below, including a 1200mm water main and 600mm storm water line. Meticulous survey and engineering was required, to ensure at least 1m clearance from any of this existing infrastructure.

Whitescape designed a piling scheme within these stringent parameters, which was approved by the structural engineers. Further adjustments were needed after a second probe to check pile locations, at 2.5m depth, identified unrecorded foundations, an underground culvert, and an older, disused storm drain. Six piles had to be relocated and the pile caps redesigned during construction.

The new structure incorporated stormwater drains with Q-Ceptor oil separators to filter outflow to the Thames, and manifold chambers for access to a geothermal heating and cooling system laid under the road surface. A sprinkler main with two entry points to the buildings was installed along the length of the site between the road and the buildings, as well as eight service ducts and 12 chambers for the IT and M&E infrastructure.

Engineered to demanding standards

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Having worked closely with Whitescape on the Hampton waterworks development, a project which had a number of difficult buried services to navigate, we would highly recommend them for any future projects. The process threw up various unforeseen challenges which were overcome remarkably smoothly, with the standard of Whitescape’s work remaining consistent and to specification. We have greatly appreciated their proactive attitude and look forward to working with them in the future.

KATE BUXTON - Hockley and Dawson, Consulting Engineers

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• The first task was to install temporary fencing and analytic CCTV, followed by removal of the old concrete road, crash barrier and boundary fence.

• A new 2m diameter manhole was built over the existing stormwater line, 4m below ground, part of the process of bringing the site up to modern requirements.

• The dig unearthed masses of concrete not shown on the historic drawings or otherwise recorded, which affected 30% of the site and required excavating to 6m in some areas.

• This extra concrete and steel were separated out for recycling, while additional resource and machines were brought in to continue scheduled earth removal in parallel.

• In total 750m3 of earth - 50 x 15m3 lorry loads - was removed per day over an 8-week period.

PREPARATION AND EXCAVATION




• 142 piles, ranging from 13m to 17m deep by 455mm diameter, were drilled in rows alongside the 220m embankment, requiring 320m3 of reinforced concrete.

• The beams were designed to cantilever over the banked edge adjacent to the filter beds, to maximise the road surface area, make provision for adequate parking and allow Thames Water access to the infrastructure below.

• Accuracy was known to be critical as it was necessary to allow 1m clearance from the water main.

• Obstacles pushed the normal bolt tolerance of 75mm to 5mm on two piles. The knock-on effect reduced tolerance to 3-5mm across 320 bolts, with zero tolerance on the outer edge of the site next to the filter beds.

PILE AND BEAM INSTALLATION

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PILE AND BEAM INSTALLATION




FORMWORK AND ROAD CONSTRUCTION

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• The formwork had to be strongly constructed and meticulously monitored during the pouring process to eliminate any risk of contaminating the adjacent filter beds.

• 1900m3 of foam concrete filler was pumped the 220m length of the site, with the pipeline broken to control flow into specific sections. Constant attention ensured a continuous flow to avoid the risk of blockages over this distance.

• We met the target of pouring at least 200m3 foam concrete for four days a week (930m3 per week) over a period of

two weeks. A planned break to avoid traffic congestion during the Chelsea Flow Show was used to install the remainder of the beams.

• The road itself was constructed as a structured formwork of slab, re-bar and mesh encased in 15N concrete to create a sound foundation for the block paving finish.

• To allow ongoing access to the water main over the cantilevered parking area, excavators were used to install pre-cast removable panels, 5m in width and weighing up to 2.5 tons.




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FORMWORK AND ROAD CONSTRUCTION




Even on a normal construction site, the Morelands-Riverdale road project would have required excellent planning and sequencing. On this historic brownfield site, fraught with known and unknown risk factors, the logistics were unusually challenging.

‘Can do’ solutions for complex problemsWhitescape deployed our own plant and a directly employed workforce of around 15 people to maintain full control over every phase and activity. Meanwhile, the client was carrying out internal and roofing works, with the buildings being scaffolded and up to 30 of their own people on site at any one time. Collaboration and communication were vital in a project where stakeholders included the client acting as his own main contractor, Thames Water and English Heritage.

“Whitescape has demonstrated great capability for the most complex of construction tasks. The vast concentration of critical, buried infrastructure has required an extraordinary level of care and accuracy, and the work has so far been completed without a single complaint or concern from Thames Water. This challenging combination of tasks and location has not once intimidated Whitescape; issues have always been met with a confident, ‘can-do’ attitude, and their diligence has set a benchmark for all other contractors on site. Most valuably, Whitescape has done what is expected, when expected, for the cost expected. Contractors that consistently manage to achieve all those three things are very rare.

K N B PRICE - Belu Architectural Design & Conservation ”

A proactive approach to Health and Safety was critical on a site with electricity, water and other unknowns - including potentially unexploded bombs. The site adjoins a residential area, so a pre-start meeting was held and regular updates given. Consideration and care was exercised at all times, with strict working hours and controls on noise and pollution.

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Whitescape’s role is to provide a technically excellent result, no matter what potential difficulties emerge. A ‘can do’ mindset is essential. With positive and intelligent thinking, obstacles can always be overcome, and solutions found, without compromising the outcome. In this project, we are proud to have satisfied our customer and shown how our strength, expertise and attitude enable us to deliver complex projects with success and certainty.




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• The brownfield site is in a heavily congested part of London. The long, narrow, restricted working area with absolutely no access to adjacent Thames Water filter beds called for precise scheduling of work programmes, deliveries and other vehicular movements.

• Timing was difficult: the project began in mid-winter and we were competing with major contractors for large quantities of materials in the peak summer period.

• The highly workable programme progressed one step at a time. This allowed flexibility to plan each stage according to the ever-changing worksite environment, adapting technical specifications along the way.

• Planning was particularly critical in the pouring phase when we had to give 2/3 days notice to suppliers, carefully balancing the risk of unforeseen factors against the need for operational continuity.

• Our onsite resource was proficiently managed to ensure that the right skills were always available and instructions were followed with absolute attention to detail.

• Whitescape had direct access to architects and consultants, and evolved a close working relationship with the structural engineers, as we tackled daily challenges together.

PLANNING AND RISK MANAGEMENT




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RESPONDING TO THE UNEXPECTED

• The spaghetti junction of pipes, wires and unknown elements below the ground required us to maintain constant vigilance at every stage of a project where nothing could be taken for granted.

• Unpredicted concrete masses encountered during the dig meant excavating 30% of the site to a depth of up to 6m, rather than the general 2.5m. Additional heavy equipment was called in to deal with this complication.

• With six machines and 10 operatives on site, we were able to separate out the extra concrete and pipework while keeping 10 earth removal trucks a day on turnaround, within the strict 08.00-18.00 working hours.

• 2500m3 of recycled hardcore had to be delivered to fill the voids left by the masses of concrete, all during the same period as 1760m3 of recycled hardcore was being brought in to construct the piling mat.

• Over 20 pipes were discovered during excavations, all of which had to be identified, tested to see if they were live, and dealt with accordingly.

• The listed brick boundary wall was found to be leaning towards the filter beds, to which we had no access. A steel frame fixed to the wall and cemented at its base acted as a counterweight to pull the wall upright, without damaging its historic significance.




The Whitescape civil engineering teamOur Civil Engineering team has all the knowledge and expertise needed to tackle complex infrastructure projects across a wide range of sectors. Each member contributes specialist skills and experience, while the whole team works together as a seamless unit to deliver the multiple planning, technical and logistical aspects of the project.

MICHAEL TIERNEYAs Service Leader, Michael works with customers to understand their needs and ensure that every aspect of the project is aligned to meeting their goals.

IAN COXAs Commercial Director, Ian contributes his specialist expertise to overall design and budget at the key pre-construction stage.

LUKE BLACKWOOD As Site Assistant, Luke provides support and backup. He is one of Whitescape’s in-house trainees, learning our specialist skills onsite.

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AUSTINHEDGECOCKAs Pre-construction Manager, Austin details the building design and specifies materials and components to realise the architect’s concept.

NICK KNIGHTAs Operations Manager, Nick has overall control of planning and procurement, working closely with customers on all operational aspects.

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Whitescape Ventures LimitedThe Stone Barn, Brows Farm Business Park,Farnham Road, Liss,Hampshire GU33 6JGT: 01730 894776 F: 01730 894198E: [email protected]