Installing a large underground concrete structure is not an unusual task for any contractor working in the water industry. Whether it’s a filtration chamber, settlement tank or storage system, installing such a structure is always a challenge. It requires a large, deep excavation support that must be made safe for people to work inside, considering ground pressure, any adverse surcharge loadings, safe access/egress and emergency procedures. Normally, once the excavation has been completed and a shoring system installed to prevent the sides collapsing inward, then the construction team can erect the formwork, pour the concrete and install any associated components such as pipework, valves or culverts. At the Mannofield Water Treatment Works near Aberdeen, contractor ESD (a joint venture between Binnies, Galliford Try and MWH Treatment) is carrying out an £8 million upgrade for Scottish Water to improve the resilience and function of the plant and ensuring a continuous supply of fresh drinking water for the city of Aberdeen. The site team is nearing the end of the first phase of the three-phase scheme, part of which has involved the construction of a large in-situ reinforced concrete access chamber below ground. This was installed in early 2023 but, due to the complex sequencing of the works, while the chamber itself was completed, the pipework serving it was not installed at the same time, creating the design dilemma of supporting adjacent existing embankments and retaining walls and exposing the structure and pipe network to be installed. So earlier this year, specialist sub-contractor CHAP Civils was appointed to excavate the soil surrounding the chamber to expose three of its four sides and create space in which ESD could carry out the pipework installation in a safe working environment. “That’s the whole complexity of it,” says CHAP Civils’ contract manager Sarah Herd. “Ideally, the shoring should have been installed and both the chamber and pipework completed at the same time. Instead, we had to excavate around the chamber and find some way of supporting the sides of the excavation while the pipework was installed.” To find a solution to this challenge, CHAP Civils worked very closely with Groundforce Shorco, the specialist ground support division of hire group Vp plc to carry out Temporary Works Design solutions for approval with main contractor ESD. “My job is basically the middle-man, the temporary works co-ordinator liaising between the main contractor and the temporary works supplier,” explains Ms Herd. “We subcontracted the support structure design to Groundforce Shorco. CHAP has worked with Groundforce Shorco several times before and although I’ve only been with CHAP for four months, I had also worked with Groundforce Shorco in my previous employment,” says Ms Herd. The excavation extended around the north, east and west sides of the chamber with support needed on all three sides, plus a section to the south. The excavation was lined with steel sheet piles and braced on two levels to the concrete structure. The longest side, to the north, measured almost 24m in length; the eastern side was 13.3m long, the southern section 6.7m long and the western side was 7m long. The irregularity of the excavation was more of a challenge than the lateral forces imposed by the retained sides of the excavation, explains Ms Herd: “The excavation was about 5.250m deep and the ground conditions were fantastic – you couldn’t have better ground conditions, really, so the lateral loads were not massive.” This was just as well because, with the concrete chamber already installed, Groundforce Shorco had to provide a bracing design that transferred the loads from the sides of the excavation to the chamber itself. Groundforce Shorco produced the temporary works design for CHAP Civils and these were passed to ESD for approval. Akil Jasm, chief engineer for Groundforce Shorco, said: “We were expecting very high loads, to be honest, but when the contractor started to dig we soon realised that the ground was better than we first thought.” “But the fact that the access chamber had already been installed made the job very challenging, so we had to find a bespoke solution which was not only safe but also provided adequate room for the installation of the pipework. Also, we needed to ensure that the integrity of the concrete chamber was not compromised due to the loads coming on to the tank from the props. Although the ground conditions were good, there were earth embankments behind the sheet piles and the sides were not self-supporting.” The design utilised Groundforce Shorco’s modular propping system. Two levels of hydraulically-adjustable Mega Brace beams were ranged along all sides of the sheet-piled excavation and the corresponding sides of the concrete chamber. These were supported by a combination of MP50, MP60 and MP150 props to brace the sides of the excavation. Mega fixed extensions were installed against the concrete chamber to uniformly spread the load on the concrete chamber rather than fixing the props directly on to the chamber. This would have subjected the chamber to high concentrated or point loads. To provide as much working room as possible, Groundforce decided to use a single prop on the eastern side, resulting in 6.7m long unsupported span. Here, Groundforce Shorco used one of its 150 tonne-capacity MP150 hydraulic props to brace the lower level of Mega Brace beams. The top of the excavation was braced with one MP50 prop – a 50 tonne-capacity unit. The rest of the excavation was braced with 10 MP60 props – three pairs along the north side and the other two pairs to the western side. Groundforce Shorco used KD6 overlapping steel sheets to line most of the excavation but those along the western side were interlocking GFI sheet piles. The western side of the excavation was open-ended and too narrow to close the end. Therefore, there was risk of lateral movement of the Mega Beam on the western side. Hence why it required interlocking sheet piles and to weld the beam to the piles. Because they are interlocking, the GFI sheets

In a bid to enhance the practical knowledge and on-site safety of those involved in temporary works, PERI regularly delivers product awareness training workshops. Last week, the formwork and scaffolding specialist held its first training workshop for temporary works engineers, site managers and designers at Laing O’Rourke. The hands-on training took place at PERI’s training facility and exhibition hall in Brentwood, building on a series of similar successful events previously held for other sub-contractors in the industry. Hands-On Training Focus The one-day workshop, delivered by PERI’s Field Services Manager and experienced scaffolding instructors, covered a wide range of practical and theoretical topics designed to improve the group’s understanding of equipment safety and proficiency when designing solutions and carrying out temporary works checks on site. Key training activities included: The workshop was attended by engineers and temporary works designers at various stages in their career, highlighting the importance of continual professional development at both graduate and more experienced levels in the construction industry. The training was particularly valuable for those involved in checking temporary works systems on-site prior to concrete pours, ensuring that any potential damages or deviations from the drawings could be identified and corrected. Anu Adeyemi, Graduate Engineer at Laing O’Rourke said, “My role involves carrying out temporary works checks, so workshops like this help to simplify the terms and system components you come across on site. Everything is broken down so it’s easier to understand.”   Terry Hall, Field Services Manager at PERI UK emphasised the importance of hands-on experience in an industry where many engineers may only have classroom-based training or experience with 3D drawings. “It’s critical for people to see and handle the actual materials and equipment they will come across on projects. A lot of people may not have this practical knowledge, yet they are tasked with reviewing drawings. For many, this is the first practical training programme that has helped to bridge that gap,” Terry explained. He added, “By seeing the issues on-site, such as deviations from drawings or improper practices, attendees gain a better understanding of how to refer back to the drawings for best practices. This is key to maintaining safety and quality.” Building, Design & Construction Magazine | The Choice of Industry Professionals

Above and below ground temporary works specialist, Altrad RMD Kwikform, has launched a ground breaking new solution to reduce the effects of thermal loading – the Tubeshor Active Thermal Compensator (ATC). The Tubeshor hybrid hydraulic shoring system is used for propping waler beams or capping beams of large excavations. It comes in a range of diameters to cater for all duties of shoring requirement. An evolution of Tubeshor, the ATC is a revolutionary patent protected Tubeshor accessory that can reduce thermal loading by up to 90% compared to a mechanically locked off prop. Prop installation and pre-loading on site is carried out in the same way as for any standard proprietary prop, so no special operative skills are needed. What’s more, as Tubeshor ATC Units are assembled directly into the prop makeup, standard prop end-fittings such as Swivel Units and Spherical Bearers can be used, and props can be installed into the excavation in the usual manner. The Tubeshor ATC contains a 450 tonne hydraulic cylinder coupled to a bladder accumulator which is pressurised to suit the individual prop design geo-load before dispatch. Most of the time, the pressure in the accumulator exceeds that in the hydraulic system and normal prop stiffness results. When higher temperature forces excessive prop thermal expansion, the compressed nitrogen in the accumulator comes into play and results in a phase of reduced prop stiffness. This means that a further increase in prop length resulting from thermal expansion does not result in the usual increase in prop load. Ian Fryer, Global Product Innovation Director at Altrad RMD Kwikform, explains: “Once the props have been installed, their confined nature means that temperature changes bring about changes in the axial prop load with axial loads increasing as temperatures rise and decreasing as they fall. “Historically design for thermal loading has not been such an issue in the UK due to the relatively even climate. However, Consulting Engineers are now interpreting industry standards differently, meaning an increased contribution from solar gain also has to be taken into account, which, when combined with seasonal and daily variations can produce a design thermal range in excess of 35 ̊C. “Using this temperature range, thermal loading can account for 50% of the axial load capacity of the props, so half of the steel in the excavation is there purely to take account of thermal loading. The resulting need for larger or more props can sap scheme efficiency, push up the equipment cost, and take up valuable excavation space. “What’s more, installation may require heavier plant and more labour to assemble the equipment, incur greater costs for transportation and result in a larger carbon footprint. Our revolutionary new Tubeshor Active Thermal Compensator helps to mitigate these factors, reducing thermal loading by up to 90% compared to a mechanically locked off prop, while offering a raft of additional benefits.” Key features and benefits To find out more about the Tubeshor Active Thermal Compensator, go to https://www.rmdkwikform.com/gb/products/tubeshoratc/ or email info@rmdkwikform.com. For more on Altrad RMD Kwikform, please visit www.rmdkwikform.com Building, Design & Construction Magazine | The Choice of Industry Professionals

Altrad RMD Kwikform (Altrad RMDK) has supplied a large-scale bespoke temporary works solution to Balfour Beatty VINCI Joint Venture (BBV JV) to support the construction of the new ‘Curzon No. 3 Viaduct’, as part of the new HS2 Curzon Street railway station in Birmingham City Centre. The formwork and falsework aids the construction of four viaduct decks which will be coming out of the station and merging into one single bridge deck featuring three high-speed tracks. The falsework configuration needed to be designed in a particular way to allow the transfer of the loads from the concrete deck and wind forces down into the foundations without overloading the structure, ensuring it could support itself at all stages of erection, in-situ concrete pouring and dismantling. Altrad RMDK’s engineers also made the provision to ensure that after the pour of concrete, the site team could easily and safely move the falsework and formwork deck units to be re-used elsewhere on the site. Versatile and connected equipment To help support the construction of a structure of this size, Altrad RMDK had to specify several interconnected products, combining their Rapidshor falsework system with Alform aluminium beams and Superslim Soldier formwork beams to create the formwork cradles. Slimshor propping with clear span steel beams and further Alform decking beams were used to support the deck soffit over the “V” shaped void in the piers, with Megashor wailings to stabilise the side shutters. A fully braced falsework system was the chosen method of support, with supports at 1.2-metre centres down the length of the viaduct. A fully braced method was required so that the structure would not move in any direction and was entirely restrained by its internal bracing. Altrad RMDK achieved the deck profile with a system of aluminium wailings & Superslim primary beams – which sat on the top of the falsework and incorporated a cantilevered support to the wings of the deck. Again, this ensured the structure was then all internally supported – mitigating the need for use of external props to the ground. Due to the tight radius curves on the underside of the decks, a special formwork solution was designed to ensure the desired form and finish was met. Altrad RMDK worked closely with Cordek Ltd for this part of the project to precisely achieve the right shape and finish, devising a complete solution for the rounded corners, which proved to be rather complicated. Maximum efficiency and safety To ensure the project was a success, the formwork solution had to be as efficient as possible. The safe working load for the Rapidshor legs is 8 tonnes; and the engineering team took the design close to the limit at 7.85 tonnes. Doing this allowed the project to be completed efficiently and safely without compromising the foundations and preventing overloading. To minimise the dangers that arise when working at height, the falsework solution was designed so that it could largely be constructed horizontally and connected before being craned into a vertical position. By erecting horizontally as opposed to vertically, it meant that the time working at height was greatly reduced, improving safety conditions on site. Despite the large scale of the project, the innovative design of Altrad RMDK’s solution improved the sustainability of the project as it allowed the whole temporary works structure to be lifted away and then be used elsewhere on site, saving the customer time and money as the falsework and formwork did not need to be taken down and re-built. Cliff Shepherd, Senior Project Engineer at Altrad RMDK, said: “This has been one of the largest projects that I have worked on in my career of over 33 years, and the entire Altrad RMDK team are extremely proud to be a part of this historic scheme. This is a brilliant example showcasing not only Altrad RMD Kwikform’s engineering excellence, but also demonstrates how inter-compatible and versatile our equipment is when working together to form very complex shapes.” Lenka Vošvrdová, Senior Agent at Balfour Beatty VINCI’s Curzon Street site, said: “We recently completed the first sections of our Curzon 3 Viaduct – a significant moment for everyone connected with this iconic structure in the middle of Birmingham city centre. “This achievement was only possible thanks to the hard work, skill and expertise demonstrated on a daily basis by the Balfour Beatty VINCI site team and our supply chain partners.” For more on ALTRAD RMD Kwikform, please visit www.rmdkwikform.com Building, Design & Construction Magazine | The Choice of Industry Professionals

Global leader in formwork, shoring and groundworks solutions, Altrad RMD Kwikform (Altrad RMDK), has completed a complex project aiding construction of a Traction Substation (TSS) at Euston Station on behalf of Principal Contractor Mace Dragados, using revolutionary ground shoring techniques for basement excavation. The TSS at Euston Station is designed to convert London Undergrounds’ private High Voltage (HV) supply to Low Voltage (LV) and Direct Current (DC) supplies to power trains and stations. Its construction required a 20-metre-deep excavation to be supported by 3no. levels of temporary propping. Unique selling points The Altrad RMDK solution provided met two key criteria; the first being that all its equipment is CE-marked, making it the only supplier on the market to offer equipment with full European compliance across its fleet, which conforms with relevant EU health and safety or environmental protection directives. Additionally, Altrad RMDK’s ground shoring equipment is fitted with mechanical screw collars – another feature unique to the company. This innovation isolates the hydraulic jacks from load transmission, thus preventing the chance of hydraulic failure whilst providing a more robust and stiffer propping arrangement with higher deflection control. Thermal loading Further to props withstanding earth and surcharge pressures, there are daily fluctuations in prop forces due to ambient conditions, including exposure to heat and UV rays, and these conditions must be considered when calculating and monitoring the effects of thermal loading. Seasonal variation and exposure to light can significantly affect the load on the props. For example, props operating in full sunlight will behave differently and attract more load compared to those providing support in shaded areas. Thermal Criteria/Load monitoring The codes and guidance currently available for the design of thermal actions against structures are aimed at above ground permanent steel structures – meaning that each prop level would have to be designed to the same thermal criteria irrespective of its timeframe of use or installation depth. As the propping application for the TSS box was for a 20.0m deep substructure with multiple prop levels at 0m, 7m and 14m below ground level respectively, Altrad RMDK felt a novel design approach was warranted to achieve a more economical and representative design solution. Drawing from experience in previous projects where actual total prop loads are typically between 40 – 60% of design loads, Altrad RMDK proposed the temperature ranges for each propping level be determined individually based on UK MET office data records and actual installation/removal dates, whilst using diminishing effects of solar gain over excavation depth. This approach resulted with load reductions of circa 30% compared to conventional design codes. To justify their rationalised approach, Altrad RMDK constructed a digital twin of the excavation in VR which was geographically aligned to real site location including models of all surrounding buildings to better understand the effects of sunlight throughout the construction period. For a true insight into actual prop loads, and as an added measure of contingency with their approach, Altrad RMDK deployed high-capacity load cells, namely ‘HD E-Pins’, across all 3 levels of propping – providing real time load results with alert notifications against pre-determined trigger levels. The HD version of the standard E-Pin were newly developed for this project to eliminate the need for traditional strain gauges, which can add further complexity in regard to set up, maintenance and axial load determination for propping applications. The highly loaded middle level props were also painted white to further boost the thermal range allowance – as a ‘bright’ surface colour provides lower relative solar absorptivity compared to the standard factory orange finish of Altrad RMDK props, thus attracting less thermal load. By adopting this rationalised design approach for the Euston TSS box, more could be done with less, allowing Altrad RMDK to detail propping in smaller quantity and size; providing the clients with more working room whilst requiring less transport and reducing the overall cost of the build. Ajay Nagah, Engineering and Major Project Manager – Ground Shoring at Altrad RMD Kwikform, explains: “This project was such an honour to work on and gave us a chance to showcase our expertise and innovation in ground shoring. We are proud of the value engineering we were able to achieve with thermal loading. “We look forward to working on further projects with Mace Dragados and HS2 and hope to continue pioneering and innovating with new equipment and techniques, which enable us to pass on cost and time savings to our clients.” For more on Altrad RMD Kwikform, please visit www.rmdkwikform.com Building, Design & Construction Magazine | The Choice of Industry Professionals

Groundforce Shorco has supplied a space and time-saving solution to a project at a wastewater treatment works in Kent. Main contractor Clancy is installing a new storm tank for Southern Water at its Westbere wastewater treatment works near Canterbury. The new storm tank will accommodate surface water surcharges during periods of heavy rainfall, helping to prevent the discharge of raw sewage into the nearby River Stour. The tank comprises six precast concrete rings of 15m diameter installed one on top of the other to a depth of 6.5m. Each ring is made up of 16 interlocking caisson segments. The concrete segments are made by FP McCann and supplied through heavy-side materials distributor Keyline. To accommodate this tank, Clancy will dig an octagonal excavation to a depth of 7m. To support this, Groundforce Shorco is supplying 120 interlocking 6m GFI steel sheet piles driven to a depth of 6m using an excavator-mounted vibrating hammer Mueller MS4 supplied by Groundforce’s Piletec division. Once Clancy has installed the sheet piled cofferdam, it will excavate to a depth of about 1m at which point the top of the cofferdam will be braced using Groundforce Shorco’s modular hydraulic Mega Brace system. Clancy will then continue to excavate to formation layer before casting the base slab for the storm tank. “The excavation is octagonal because it makes no sense to dig a rectangular hole for a circular tank,” explains Clancy project manager Oliver Smart. “The octagonal excavation reduces the amount of muck away and requires less kit and less materials,” he adds. The excavation can follow the perimeter of the concrete tank closely while providing sufficient space to accommodate the bracing. “It’s a challenging design and excavation but the Mega Brace adaptability made it easier,” explains Groundforce Shorco area sales manager Arpad Nagy. “The Mega Brace is a modular bracing system and is very adaptable. It’s easy to install whatever the shape of the excavation and in this case, an octagonal excavation requires less equipment than a square one would. With the octagonal shape the muck away has been reduced by 20%, in this case 200m3. The excavation has been reduced with 10lm worth of sheet piling and 30lm worth of bracing. On this case we’ve managed to reduce the carbon footprint which helps reduce the environmental affect.” Groundforce is one of Clancy’s preferred suppliers of temporary works equipment. “I’ve worked with them on several projects,” says Oliver Smart. “The kit is great and Groundforce has a good design capability. They are providing on-going support and technical advice on this project.” Building, Design & Construction Magazine | The Choice of Industry Professionals

Several Doka SKE50 plus hydraulic and Xclimb 60 crane-lifted climbing formwork systems are being used to construct four new town centre towers that are at the heart of   Southwark Council’s Elephant and Castle redevelopment programme. The development will transform an area of South East London that was once compared to Piccadilly Circus on account of its dynamism and vibrancy. The huge works programme, which is being carried out in three phases, will lead to the creation of a new town centre. It will include 1,000 new homes, an upgraded Elephant and Castle tube station and the building of a cutting-edge campus for nearby London College of Communication, part of UAL University of the Arts London.  Contractor Morrisroe selected Doka to provide its design expertise and innovative hydraulic climbing formwork for the construction of the concrete cores that will form the three of the developments multi-storey tower blocks. Each block will comprise a standard concrete finish featuring Doka Framax Xlife panels. These are being installed using Doka’s SKE50 plus hydraulic climbing formwork. The crane-independent system includes an all-round enclosure that makes for safe, weather-shielded working at any height. Such is the SKE50’s robustness and reliability, it facilitates the floor-by-floor lifting of internal-external materials whilst protecting operatives carrying out the rebar process in preparation for casting concrete. The all-hydraulic crane-less climbing method optimises construction workflows by allowing greater flexibility in respect of cycling the SKE50 units’ repositioning. The fourth core, which was the first one to come out of the ground, was constructed using the Doka Xclimb 60 crane-lifted solution. This system was chosen primarily because this tower was much lower than the others. Additionally, it was originally specified as a cost-effective option due to the fact that the slab was programmed to follow, and it was completed before the cranes were too heavily utilized on the rest of the vast project. As well as reviving Elephant and Castle as a thriving social, cultural, and commercial hub, it’s estimated the town centre development will create 1,230 construction jobs over the ensuing decade. Approximately 2,000 full-time jobs will ultimately be created upon the wider development’s scheduled 2030 completion. This is a blue-chip project in a characterful, historical area of London that thanks to Doka and a myriad of skilled, visionary stakeholders, will see Elephant and Castle prosper as a redeveloped cultural hub. Building, Design & Construction Magazine | The Choice of Industry Professionals

Doka Slipform solutions ensured the rapid, efficient construction of a high-rise concrete core that is integral to a standout redevelopment in London’s financial district. The project involves the construction of 2 Aldermanbury Square, a 12 storey, grade A office building with market-leading sustainability credentials located in the City of London. The redevelopment will increase its lettable area significantly from 180,000 sq ft to 320,000 sq ft and incorporate public realm and amenity improvements designed to positively impact the local area. Selected by specialist concrete sub-contractor Keltbray to construct the building’s 65-metre core, Doka took an innovative approach to the formwork specification and assembly in order to accommodate 12 lift shafts, two lobbies and two staircases within the core’s construction.  Architectural demands led to the walls of the two cores being constructed using Doka’s Slipform system. The project’s size and scale demanded a solution that facilitated a safe build at rapid speed. Doka Slipform delivered on both counts. The system enabled the pouring of about 80m3 of concrete per working day on the vast concrete structure. An additional benefit of Doka’s Slipform system was its easy maintenance and cleaning capability, enabling its readiness to begin effective operation during the strict council-allotted time provided. Up to 11 deliveries of ready mixed concrete per day were required in the construction process, resulting in Doka’s Slipform system exceeding the originally planned ‘climb’ target of 1.7 metres per day by an additional 0.3 metres. Doka’s excellent working relationship with Keltbray was key to the concreting aspect’s success. Even before the commencement of site activities, the partnership began with Doka’s specialist Slipform supervisor overseeing pre-assembly works in Keltbray’s yard facilities, an alternative approach to Doka traditionally offering pre-assembly works and labour from its own yard.   With space severely restricted on-site, offsite assembly and delivery of the formwork was crucial in terms of operational safety, speed and efficiency. As part of its all-around customer service offering, Doka’s technical team attended the site to oversee the Slipform process and offer guidance when required.  Doka’s innovative incorporation of two concrete placing booms onto the rig via one concrete line was requested by the contractor and the move was instrumental in facilitating a smooth concreting process. Unique to Doka’s Slipform equipment is its compatibility with a variety of Doka proprietary rental equipment. Potentially, this means customers can reuse equipment on a range of Slipform projects, which has long-term benefits in terms of cost and sustainability. The Aldermanbury Square project offered further valuable proof of Doka’s ability to design and supply formwork solutions for projects ranging in profile and complexity. The team’s skill in meeting ad-hoc challenges throughout the programme ensured the core’s time-efficient, high-precision completion. Building, Design & Construction Magazine | The Choice of Industry Professionals