Franki Company Profile

Franki Africa – leading Geotechnical Engineers in South Africa. Part of the Keller group which is the biggest in the world. Franki Africa is the largest, oldest and most established specialist geotechnical contractor in Sub-Saharan Africa.  Franki offers a comprehensive range of services which ensures that its customers benefit from the most cost-effective solutions for their geotechnical requirements.

Franki operates in sub-Saharan Africa and the Indian Ocean Islands and, together with Keller, has the experience, capability and capacity to undertake projects of all sizes.  The comprehensive product range at Franki is further enhanced by its in-house geotechnical investigation capability, as well as its Design Department.  Being part of Keller (www.kellerholding.com) also widens our product range, capacity and capability

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[Johannesburg, 11 July 2019]: Franki Africa has installed Rigid Inclusion columns on a design and construct basis for the ongoing Clairwood Logistics Park project in Durban – the first time this method of ground improvement has been used in South Africa.

Franki Africa has been working on the Clairwood Logistics Park project since 2017 where it has already completed 60% of the original scope. The progress of the project has slowed down as the client needs to secure tenants before the final scope can be completed.

Franki was contracted to install Rigid Inclusion columns to improve the underlying hippo muds which extend to depths in excess of 35 m. The scope of the project entails about 368 000 m² of treatment footprint to install approximately 47 100 no of Rigid Inclusion columns with 2 m stone heads.
“This is the most cost-effective solution to achieve increased bearing capacity and settlement reduction,” explains Victor Ferreira, Business Development Manager at Franki Africa.

Pile foundations have been a common solution when the bearing capacity or performance cannot be satisfactorily guaranteed by using shallow foundations. This often occurs in urban areas where increasingly higher structures apply higher forces to the ground. Pile foundations are also required where ground conditions are poor and provide little capacity or stiffness to ensure short- or long-term serviceability requirements.

Ground improvement is an alternative solution for piled foundations in poor conditions, whereby the properties of the ground are improved to allow structures to be founded on simple, shallow foundations. With Franki Africa being part of the Keller Group, a global leader in ground improvement technology, a range of ground improvement technologies are now available for the African geotechnical market.

Among a variety of these technologies is Rigid Inclusion columns. This is possibly the newest ground improvement technology which involves relatively slender concrete/grout columns to improve the properties of the soil mass. “Rigid Inclusions can be utilised to improve soils to depths in excess of 40 m with significantly higher productions compared with conventional piling methods,” explains Dr Nicol Chang, Technical Director at Franki Africa.

[ENDS]

Frank Africa contact details:
031 507 1051

MoonDawn Media & Communications
Bridgette Macheke
Tel: +27 (0) 079 5494
Cell: +27 (0)73 400 1549
Email: bridgette@moondawnmedia.co.za
Web: www.moondawnmedia.co.za

[Johannesburg, 21 June 2019]: An ambitious project timeline for the construction of Cervejas de Moçambique’s new brewery, compounded by a late start to the project due to external constraints, saw geotechnical specialist Franki pull out all the stops to ensure partial handovers of the foundations and lateral support to allow the main contractor to carry on with the works.

Franki Africa is once again proving why it is the largest, oldest and most established specialist geotechnical contractor in sub-Saharan Africa. This time, the contractor is calling on its experience in this specialist field to get the better of an array of challenges at the construction of a new brewery in Mozambique. The project owner, Cervejas de Moçambique (CDM), which already owns three breweries in the country, is a subsidiary of the largest global beer brewer, AB InBev.

Having broken ground on the construction of a more than 2-million hectolitre a year brewery to be built at a total cost of US$180-million in Mozambique’s Marracuene district, about 30 km north of Maputo, CDM went on to lay the first stone for the construction of the new brewery in early December last year. The project is the largest investment by CDM and by the beer sector at large in Mozambique since CDM’s inception back in 1995.

The new brewery, scheduled to produce its first batch of beers by the end of this year, means that its construction has a very tight timeline. Franki has been entrusted to carry out geotechnical work on the project. Marta Botelho, Contracts Engineer at Franki Mozambique, explains that Franki is responsible for the installation of foundation and lateral support piling for different structures of the brewery, like the BBT Tanks and Unitanks, Raw Material Silos, Malt Intake and Mill House.

With an initial estimated duration of five weeks, Franki’s project duration has since been extended to 10 weeks. As a result, the contract value has increased from MZN79-million (about R21,5-million) to MZN129-million (about R35,1-million) due to additional works required. A late start to the project meant a major setback to the project’s stringent timeline.

Apart from the late start, Botelho says the tight nature of the timeline was just a big challenge from the start, adding that the programme is very tight, due to the client’s plans to start operations this year.

“After a late start, we managed to guarantee partial handovers of the different areas in order to allow the main contractor to carry on with the works,” says Botelho. “Our design team worked together with the client’s engineers (WSP) to get to the best solutions and overcome any arising challenges.”

Another key challenge the Franki team had to contend with was the short supply of readymix concrete. There is a long distance from an existing batch plant to the site. “We used different suppliers and our own concrete transit mixers to minimise this challenge. Due to the tight nature of the programme, we also had to resort to working extended hours,” says Botelho.

With a total of 60 people on site, including 18 subcontractors for steel fixing, Franki’s project scope encompasses different piling technologies, including the Continuous Flight Auger (CFA) piles and the Driven Cast-in-situ piles, also known as Franki Piles, with diameters ranging from 410 to 800 mm. Franki will install a total of 707 piles, comprising 142 no. CFA and 367 no. DCIS foundation piles, as well as 81 no. Grout Columns, 117 no. CFA piles and 243 m² of Gunite arches in lateral support.

Commenting on the choice of piles, Botelho says CFA piling is a fast system with no vibration and limited noise levels associated with it. Franki Piles, on the other hand, are the most economical and reliable piling system in southern Africa. Developed about 70 years ago, the Franki Pile’s main feature is the large base formed at the toe of the pile and, in forming it, the end-bearing area is considerably increased. Generally a very economical system, it has an extensive range of pile sizes.

To execute the project, Franki has a range of equipment for each of the setups. For the CFA setup, the geotechnical contractor has deployed the Casagrande CFA-26 auger rig and the Sany HBT-40 concrete pump. A Franki Rig SA83 and a 60t Ajax C60 are being utilised for DCIS setup. In terms of auxiliary equipment, Franki has deployed a Tadano TI mobile crane, the two Fiori transit mixers and two TLBs. “For lateral support equipment, we have on site a Comaachio Geo 305 drill rig and a single Mat Pump. Proper selection of equipment is very crucial to ensure timely delivery of the project,” concludes Botelho.

Frank Africa contact details:
031 507 1051

Bridgette Macheke
MoonDawn Media & Communications
Tel: +27 (0) 079 5494
Cell: +27 (0)73 400 1549
Email: bridgette@moondawnmedia.co.za
Web: www.moondawnmedia.co.za

[21 May 2019]: When Edgard Frankignoul, invented the Franki pile in 1909 he had no idea that 110 years later it would still be regarded as one of the most cost-effective and reliable solutions for a host of different geological conditions.

“It’s quite amazing,” says Franki Africa’s Gavin Byrne, “that with only relatively small improvements over time, the Franki pile, after so many years, repeatedly remains the solution of choice in a wide variety of conditions. Given that we operate in an ever-changing and advancing technological environment makes the ubiquitous nature of the Franki pile even more remarkable.”

“Above all, the Franki pile is a unique system for generating excellent load capacity and we have developed a number of techniques to install it in a variety of soil conditions,” adds Byrne. “With its wide range of pile sizes and its characteristic enlarged base, it’s fair to say that the Franki pile has been one of the cornerstones of Franki Africa’s success in southern Africa.

The latest project to demonstrate the magic of the Franki pile is the piling work done for Sappi at its Saiccor mill in Umkomaas, KZN.

The Project

Sappi’s project includes the installation of a new evaporator, recovery boiler and screening and washing plant, along with upgrades to the bleach plant and pulp machines, improved recovery circuits and additional magnesium digesters. The piling tender for all these elements stipulated the installation of approximately 1900 piles to varying depths.

Difficult Ground Conditions and Record Depths

“I would say that the ground conditions on this site were among the most difficult in Franki’s 75 years of installing piles in the Southern African region”, says Byrne.  “From our initial design and construct perspective, we had no doubt that the Franki pile would be the most cost effective and technically robust solution for a variety of reasons.”

The fact is the conditions actually encountered on site revealed even greater variations in the geological profile than was expected. Not only would piles have to be installed at depths of 24m – an all-time record for the company – but installation would also have to be performed at very shallow depths of between of 5m -8m.

Byrne says it is not only this significant variation in depth that was challenging but also how quickly the founding depth changed. “Over large parts of the site the founding depth would vary by as much as 15m. This was perhaps the single most challenging condition of the site and necessitated very careful site planning and fast and constant evaluation of the deeper areas of founding to ensure that the heavy equipment could be continuously utilised.”

In a nutshell, Franki has had to deal with some of the shallowest conditions it has ever dealt with juxtaposed with the deepest it has ever had to deal with and the Franki pile proved to be exactly the right solution. “This is mainly because the Franki pile accommodates a wide variety of difficult founding conditions and provides remarkable settlement performance and load capacity”, explains Byrne.

Not the end of the Franki pile’s advantages

One of the stipulations was that the piles had to resist uplift forces.  Franki’s Jonathan Day, who was instrumental in the final design of the job, says any other pile like, for example, auger or CFA piles, would have been a much more expensive and complicated solution due to these piles having to be socketed into the bedrock.  “The Franki pile’s large base is the best solution in this regard mainly because it can be founded on the rock surface while providing superior uplift capacity,” he says.

Two more site conditions reinforced the choice of Franki piles. Firstly, there were boulders at localised portions of the site at various depths and Franki piles are able to penetrate the boulder horizon. Secondly, across the majority of the site there are very soft silty clays and the Franki piles are ideal for driving through such material with the Franki pile casing preventing collapse of the material and ensuring the integrity of the pile shaft concrete.

A wide range of equipment for the job and the timing challenge

A total of six piling rigs are being used on the job. These include three standard Franki crawler piling rigs for the shallower piles, an Ajax 55t crane with leader for the piles to about 17m, a 70-ton Liebherr for the 18m -20m piles and the recently introduced large Liebherr crane ( 90t) for the deeper piles including Franki’s deepest, history-making piles of 24m.

Day says that the timing has been one of the important challenges of the job. “Our client required certain key milestones to be achieved and set stringent targets for each section of the job. In this regard I am pleased to say that we have completed the first sections on time and on budget. The excellent relationship between ourselves and our client Sappi has been fundamental to the success of the project thus far,” he concluded.

Meanwhile Errol Braithwaite, Franki MD, says that he is proud of the quality projects that Franki is currently involved in, especially in this very challenging economic climate. “There is no doubt that the construction industry in Southern Africa is facing one of the most pressured periods in its history – many companies are having to reinvent their business models, some will close, foreign companies are entering the market, skills are exiting the market and confidence is down.

“In spite of this, however, I remain confident about the future. In our own organisation we are still experiencing a buoyant order book and, importantly, we are seeing excellent young talent emerging which is more representative of our diverse nation than ever before. Through our parent company, Keller Group plc – the largest independent geotechnical construction company in the world – we have unprecedented access to international expertise and technologies and, with Keller, Franki has a local presence in African cities stretching from Cape Town to Nairobi, from Accra to Mauritius and many places in between.”

Franki Africa has a long history of success on the African continent and its experience and expertise have been greatly bolstered by being part of Keller with which it shares all the values that will enable Franki to continue giving its clients a world class service.

“We are fortunate to have some of the best people, technologies and equipment on the continent and it is our responsibility to continue delivering excellence across the board to all our customers,” Braithwaite says.

He adds that perhaps Franki’s most important attribute is the quality of customers, like Sappi, it has attracted over the years. “This has been a privilege of the highest order and I am pleased to be able to express our gratitude to them out loud and in public.”

 

 

Bridgette Macheke
MoonDawn Media & Communications
Tel: +27 (0) 079 5494
Cell: +27 (0)73 400 1549
Email: bridgette@moondawnmedia.co.za
Web: www.moondawnmedia.co.za

Frank Africa contact details:
031 507 1051

[16 APRIL 2019]: A magnificent bridge over the Okavango River in the Mohembo Village area which is being piled by Keller’s Franki Africa for main contractor Itinera/Cimolai JV, is a shining example of Franki’s diverse strengths. Here we focus on Franki’s renowned ability to deliver in remote and challenging environments.

The bridge, which connects villages on the east of the river with the rest of the country, straddles the Mohembo East (Kauxwi) Ferry landing site with the Mohembo West (Shakawe) Ferry landing site.

According to Devendra Lalbasanth, Franki senior contracts manager, the 1,2km bridge, which consists of two towers for the Cable Stayed portion and 18 piers, requires 189 no. 1200 diameter, permanently cased auger piles at an average of 35m below platform level. Some of the piles required are being installed to a depth of 50m.

In terms of the ground conditions, the top 12m consists of alluvial deposits underlain by soft rock, schists and gneisses – metamorphic rock developed from basement granites – and there were no surprises in this regard as the Botswana Roads Authority’s geotechnical investigation, prior to and post the award of the contract, was thorough.

“More than thorough,” Lalbasanth says. “In excess of 100 boreholes were drilled and more than 700 rock-strength tests were completed. This was one of the most detailed geotechnical investigations we’ve ever seen.”

Lalbasanth says that, on the face of it, the scope of works may sound like a fairly straightforward task in geotechnical terms but the nature of the site and the surrounding area, including roads and general access, were extremely challenging especially for bringing in the specialised equipment that was required to do the job.” Lalbasanth says.

And it was no ordinary equipment that had to be transported to the site. It included a Liebherr 355 – one of the largest augering machines in Africa – two Casagrande B180s, a Bauer BG 18 and two Liebherr 845 service cranes.

“Getting this equipment to site was certainly the greatest challenge facing the Franki team. For example, before this job the Liebherr 355 was doing rigid inclusions at Clairwood Logistics Park in Durban and we converted it to an auger configuration before transporting it to Mohembo, 1500km away,” Lalbasanth says.

He adds that a huge debt is owed to abnormal load transport specialists Transcor Transportation for their efficiency and perhaps, above all, patience in the delivery of the equipment. “The trip from Durban to the site took 14 days!”

As the geotechnical work takes place on both sides of the river, it was also challenging getting the plant across the river. “For this we must thank our clients, the main contractor, who provided us with a 150t pontoon for the job.”

To date Franki has completed 50% of its work. “We look forward to seeing this bridge completed. The design shows that it will be a magnificent structure with both towers literally towering over the landscape in the shape of elephant tusks. I thank all our team, the local residents in the Kauxwi and Shakawe areas, Transcor Transporters and our clients, Itinera/Cimolai JV, for their continued efforts in ensuring a successful contract,” Lalbasanth concluded

Meanwhile Errol Braithwaite, Franki MD, says that he is proud of the quality projects that Franki is currently involved in, especially in this very challenging economic climate. “There is no doubt that the construction industry in Southern Africa is facing one of the most pressured periods in its history – many companies are having to reinvent their business models, some will close, foreign companies are entering the market, skills are exiting the market and confidence is down.

“In spite of this, however, I remain confident about the future. In our own organisation we are still experiencing a buoyant order book and, importantly, we are seeing excellent young talent emerging which is more representative of our diverse nation than ever before. Through our parent company, Keller Group plc – the largest independent geotechnical construction company in the world – we have unprecedented access to international expertise and technologies and, with Keller, Franki has a local presence in African cities stretching from Cape Town to Nairobi, from Accra to Mauritius and many places in between.”

Braithwaite says that another important competitive advantage of being part of the Keller group is that Franki has been able to bring world-class technology to the African market: the rigid inclusion ground improvement technique to the Clairwood Logistics Park in Durban, large diameter cluster hammers to the Hass Towers project in Nairobi and deep cased augers socketed into bedrock to the Okavango River Bridge in Botswana, which is discussed above.

“Indeed, there is much more that will help us to continue providing our customers with the appropriate solutions at the right price,” says Braithwaite. “This includes simplified, standardised business processes, LEAN construction and data analytics, which, along with an obsession with skills development, will underpin our continued success on this continent.

Franki’s values

Franki has always been a values driven company and its successful integration into the Keller organisation is undoubtedly, in large part, a result of the shared value system of both companies which can be summarised as follows: Integrity: Consistently acting with honesty, fairness and positive intent; Collaboration: There is a huge amount of collaboration required to take a job to fruition, both internally and with our customers, suppliers and counterparts. Good relationships and mutual respect are foundational; Excellence: Excellence is the application of skill and diligence in the delivery of every project. It is the mindset of: We can and must continue to get better. We can never be satisfied with the status quo.

Summary

Franki Africa has a long history of success on the African continent and its experience and expertise have been greatly bolstered by being part of Keller with which it shares all the values that will enable Franki to continue giving its clients a world class service.

“We are fortunate to have some of the best people, technologies and equipment on the continent and it is our responsibility to continue delivering excellence across the board to all our customers,” Braithwaite says.

He adds that perhaps Franki’s most important attribute is the quality of customers it has attracted over the years. “This has been a privilege of the highest order and I am pleased to be able to express our gratitude to them out loud and in public,” he concludes.




 

Bridgette Macheke
MoonDawn Media & Communications
Tel: +27 (0) 079 5494
Cell: +27 (0)73 400 1549
Email: bridgette@moondawnmedia.co.za
Web: www.moondawnmedia.co.za

Frank Africa contact details:
031 507 1051

[Johannesburg, 22 January 2019]: It takes more than the highest levels of ground engineering expertise and experience to be Keller’s Franki Africa, Africa’s geotechnical champion. Much more, It takes business acumen, customer service excellence, team-building skills, and a whole lot more.

Among the important skills required to wear this crown, especially in these challenging economic conditions, is the ability to reconfigure original tender specs to suit local conditions, the ability to run successful branches in African countries and, where no branches exist, to work across borders, sometimes in very remote and harsh environments often having to transport heavy machinery over very long distances.

Multisports Complex, Mauritius

One of these successful branches is in Mauritius where Country Manager Yannis Mongelard runs a tight and successful enterprise and one of the contracts which exemplifies both his branch’s and Franki’s all-round skills is the Mauritius Multisports project currently underway. The project involves the construction of a new sports complex for the Indian Ocean Games scheduled for July 2019 at Cote D’Or, St Pierre, Mauritius and includes athletic training grounds and track, a football pitch, an aquatic centre and a multipurpose gym.

The Government of Mauritius contracted the construction and development of the complex to the Mauritius Multisports Infrastructure Ltd (MMIL), a state-owned company. Mongelard says that the tender, which was launched in December 2017 with anticipated start in early 2018, stipulated 96 days for piling work. “This was not possible for a host of different reasons at that time,” he says.

Franki’s response was typical of the company’s ability to size up a situation and offer the client a different – and better – alternative. “We submitted a solution which was cheaper, allowed for an earlier start and which could considerably cut down the duration of the job under normal circumstances. Moreover, it enabled us to work with the plant we had on the island at the time, which contributed significantly to the cost saving on the project,” Mongelard says.

He adds that from the original piling-only solution in the tender, Franki further enhanced efficiencies with a solution comprising a mix of piling and ground improvement. “The original tender specs involved the installation of more than 850 Temporary Cased Auger piles of various sizes drilled to an average depth of 21 m. Our ultimate solution comprised ground improvement in conjunction with a mix of piling techniques optimised to support each of the structures.”

Mongelard says piling and ground improvement was required following geotechnical investigations, which observed worse-than-expected ground conditions. Moreover, the required bearing capacity of the backfilled soils could not be achieved and deep foundations (piles) were opted for,” he says.

The details of the accepted solutions were as follows:

Stadium & Skydeck:

  • 432 nos x 610 mm Driven Cast In-Situ piles to an average depth of 16 m
  • 33 nos x 520 mm Driven Cast In-Situ piles an average depth of 16 m

Skydeck:

  • 124 nos x 610 mm Driven Cast In-Situ piles an average depth of 16 m

Aquatic Centre:

  • 30 nos x 1 080 mm Auger piles to 20 m deep for the roof structure
  • 180 nos x 520 mm Driven Cast In-Situ piles for the back-of-house
  • 493 nos x 410 mm x 9 m deep Rigid Inclusions for the main and warm-up swimming pools

Multi-Purpose Arena/Gym:

  • 48 nos x 1 200 mm x 20 m deep + 7 nos x 1 200 mm x 6 m deep Auger piles for the roof structure
  • 629 nos x 450 mm x 9 m deep Rigid Inclusions for the back-of-house and the field of play

While these solutions could have cut down on production time, it turned out that high rainfall and the clayey platform made it almost impossible to achieve the daily minimum production from the start. In addition, the platform works could not proceed because the earthmoving vehicles were unable to work efficiently. In this regard, Franki requested a thick stone mattress in lieu of the soft soil platform. This was provided drastically, improving productivity.

“In spite of six weeks being lost due to weather and related platform issues, works have already been completed at the Stadium and the Skydeck is still under progress – the newly agreed completion time was set for September 2018. The stone mattress, an additional piling rig and longer working hours have made that a certainty,” says Mongelard.

The piling works started early June 2018 and, in terms of budget, the cost of Franki’s alternative solution will still be less than the original alternative solution – hence the project is within budget.

“This is an important and high-profile contract in Mauritius and our success is based on excellent teamwork. The ability to work as a team and the support we have got, and always get, from Brian McDonald and the head office in general, is typical of Franki’s commitment to ensuring the best possible service to its clients,” concludes Mongelard.

[ENDS]

Frank Africa contact details:

031 507 1051

Media contact:
Bridgette Macheke
MoonDawn Media & Communications

Tel: 011 079 5494
Cell: 073 400 1549
Email: bridgette@moondawnmedia.co.za 
Web: www.moondawnmedia.co.za

[Johannesburg, 7 September 2018]: The old adage that building roads and bridges is fundamental to the growth of an economy has certainly been heeded by the Saldanha IDZ (Industrial Development Zone), which, in contrast to many areas in South Africa, has been undertaking significant infrastructural development with the funds they have received from the South African government for that specific purpose.

Some of this infrastructure includes roads and bridges such as the Greenfields Link Interchange project, awarded to WBHO Construction in late 2017 and who subsequently awarded the geotechnical piling contract to Keller’s Franki Africa.

The project, initiated by the Western Cape Government: Department of Roads and Public Works, is situated in the Saldanha Bay municipal area 125km north of Cape Town.

Franki senior contracts manager, Anton Stoll, explains that at tender stage the pile founding solution was stipulated as “predrilled, based temporary cased auger piles” for all three bridges, founding in the greenish, grey mottled orange and brown dense sand, by means of basing out an enlarged base below the temporary installed casings. These piles were expected to be around 14m in length from underside of pile cap.

“From the outset we were not quite sure that the tender solution was the correct one for the circumstances,” says Stoll. “The fact is the West Coast area around Saldanha Bay is known for its difficult geology and founding conditions for many a structure, including, of course, this particular bridge interchange.

He adds that the geology of the site consists of windblown sands for around 0.5 to 1.0 m below natural ground level, followed by up to 3-4m of strongly cemented hardpan calcrete (pedogenic), then varying layers of loose, silty, clayey sand and calcrete lenses, followed by a greenish, grey mottled orange and brown dense sand. This varying profile continued to depth and a high-water table was present.

The Interchange has three bridge structures and, while the largest structure was clear of any obstructions, the other two had a water main in close proximity to the piles and pile cap, raising a concern over vibration during pile installation further complicating things from a geotechnical perspective.

The ultimate outcome was that Franki decided that the site conditions suited a different pile type and installation methodology with the varying soils, the very high-water pressure and an aquifer which became evident in close proximity to where the piling would be.

“The water had further softened the dense sand layer in places, making the formation of the enlarged base difficult due to large volumes of basing material required to improve the silty sands,” says Stoll.  “As more skips were added, the basing appeared to soften rather than densify the layer. At times, plumbs were added without effect ultimately resulting in the plug suddenly being expelled by the 6-ton hammer from the temporary casings allowing water into the casing. After a number of attempts, it was proposed that an alternative piling solution would be more suitable to the site conditions, geology and pipeline obstructions.” 

After discussion with the engineers and main contractor, Franki proposed that the two bridges with the existing water pipeline obstruction would be more suitable to CFA (Continuous flight auger) piles while the main bridge could be found on DCIS (driven cast-in-situ) Franki piles founded at a dense layer, higher up in the soil profile. This required a variety of piling rigs, service cranes and technical skills, all available within the Franki group.

Stoll says that by this time, the programme had become critical and the merits of the alternatives were debated, approved and immediately implemented with non-working test piles at each structure. Predrilling remained in order to penetrate the hardpan calcrete layer prior to installing the piles.

The test pile results proved the alternative methodology was correct and working piles were installed accordingly.

Franki has developed a reputation far and wide for finding the right solution for the job at hand. “Our experience in South Africa and in many parts of Africa in general over the years gives us an unmatched understanding of the geology and of what is required relative to it to ensure that we give our clients the most cost-effective solution,” Stoll says. “The Green fields Link Interchange is certainly not the first time that we have successfully offered a solution different from that of the tender proposal.”

Of course, knowledge is one thing but having the right hardware for the job is as important. In this case the CFA piles and the world-renowned Franki Pile, which has been used extensively throughout southern Africa for the past 70 years (and is still today one of the most popular pile-types) proved their worth in the solution.

The main feature of the Franki Pile is the enlarged base formed at the toe of the pile. In forming this base, the end-bearing area is increased significantly and the displacement achieved when expelling the plug and forming the enlarged base compacts and preloads the soil surrounding the base. Thus, the end-bearing of a Franki Pile in sands develops at much lower base deflections than that of a bored pile.

Other important advantages of the Frank Pile include: it is often a very economical system; it has an extensive range of pile sizes; it has an exceptional load/deflection performance; noise levels are relatively low; it has excellent tension load capacity.

The CFA piling system is also a fast and economical one, which has no vibration and limited noise levels. Some of its other attributes include: high production levels in suitable soil conditions; economical in suitable soil profiles.

“The fact is there are some limiting considerations to be taken into account with the CFA system reducing its popularity compared with driven piles. The conditions in the Greenfields Link Interchange, however, made the system a very successful choice,” Stoll says.

The key to the success of the piling project was the implementation of Franki’s alternative plan. “It took teamwork to get this right,” says Stoll, “and I would like to pay special tribute to Ross Dold, Nabeel Omar and Wilhelm Wessels on site for Aecom, together with Abie Newmark and Alexi Maraveilas from the Aecom office, while Stefan Herbst and Willie Broekman of WBHO Construction assisted us with the implementation.  This was indeed a great team effort,” he says.

Stoll emphasised that no project is too big, or too small, or too complex for Franki. In terms of South Africa and Africa in general we are geared up like no other geotechnical company in the world.  We have permanent offices and yards in South Africa, Mauritius, Mozambique, Tanzania, Zambia, Kenya, Ghana and Angola. We are also registered in Uganda, Botswana, Swaziland, Lesotho, Seychelles and Namibia. Our French speaking colleagues are present in Morocco, Cote d’Ivoire and Algeria and our middle eastern colleagues are present in Egypt.

“Add to this the depth of global experience that the Keller group has it becomes clear that Franki’s ability to provide a world class service in this country and across the continent is second to none,” he concluded.

 

[ENDS]

Frank Africa contact details:

031 507 1051

Media contact:
Bridgette Macheke
MoonDawn Media & Communications

Tel: +27 (0) 079 5494
Cell: +27 (0)73 400 1549
Email: bridgette@moondawnmedia.co.za 
Web: www.moondawnmedia.co.za

 

  

Introduction

For construction programmes to be compressed into the shortest possible time to meet client handover deadlines is not unusual, but for contractors to offer innovative improvements to design to realise cost and time savings is far more so – particularly when this increases the pressure on the contractor to perform! For the prestigious new Umhlanga Arch development, north of Durban, KZN, the Keller group’s Franki Africa, through innovative solutions and unusual industriousness, did just this.

The Project

Umhlanga Arch is a 45,000m² residential, commercial and hotel development situated on prime Umhlanga Ridge real estate with expansive views over the Indian Ocean. The demand for space in the suburb has been insatiable and development has been continuous even in the current tough economic conditions. Typically, an urgent start and fast track programme to ensure handover to new tenants as early as possible was demanded.

Innovation for Time and Cost Saving

When Franki’s team reviewed the tender requirements, it was clear that the earthworks and piling could not be completed within the time frames specified. Early access was required to the main structural cores of the high-rise buildings but this was inhibited by their close proximity to deep cuts into the steeply sloping site.

Graded embankments for staged piling platforms would only allow access to key core piling platforms late in the piling programme so Franki proposed additional anchored lateral support walls as an alternative and, in conjunction with the client and the project team, these were worked into the foundation design to realise overall time and cost savings.

But Franki offered many other innovative time and cost saving solutions to the earthworks, foundation and lateral support requirements which were integrated into the structural design while work continued. This included ingenious geotechnical optimisation, which resulted in the approximately 1,300 foundation piles being halved with the introduction of large diameter (750mm and 900mm) Zwidi DCIS piles.

Programme constraints were further alleviated by Franki introducing additional contiguous piled lateral support enabling earlier commencement of the foundation piling and subsequent main structure. This resulted in Franki’s lateral support scope increasing to approximately 3,000m² of anchored pile lateral support which, along with the foundation piles and earthworks, was all to be completed in less than 6 months.

Furthermore, careful coordination with the client, local authorities, other contractors and the project team resulted in bulk earthworks and piling starting simultaneously allowing the early introduction of the building contractor in yet another solution to bring the completion date forward. In addition, further temporary lateral support solutions were found to allow early access to other key areas.

The Construction Techniques

The lateral support works comprised retained heights up 9m with nearly 320 anchors up to 19m long in two to four rows. These had to support construction traffic as well as adjacent roadway traffic. The Berea Red sands are fairly consistent in this area, but CFA piles and self-drilling hollow bar anchors were used to accommodate bands of loose collapsible sands.

The added complication of installing piles behind anchored lateral support required the accurate positioning of anchors to avoid pile positions. Although there were certain conflicts, these were overcome without any major design implications.

Foundation piling began away from the deepest cuts, but access had to be provided for foundation piling to the critical cores of the main structure – some of which were close to deep cuts – in the shortest possible time. The Zwidi pile proposed by Franki is a derivative of the Franki pile and is suited to unsaturated soils, which do not collapse, found in some areas of Umhlanga Ridge.  They are large diameter piles with enlarged bases and can carry high loads. One of their main advantages is that they can be installed relatively quickly.

Building works commenced on site as soon as the first section was handed over and from then on, the main contractor for the building works applied continuous pressure on the Franki team which did not flinch and was able to provide safe access to meet the stringent deadlines. With access from one steeply sloped point only, the potential for conflict between disciplines was ever-present and required continual liaison between all concerned.

Heavy run-off from adjacent roadways and the site itself had to be carefully managed, as sites further down Umhlanga Ridge could not accommodate concentrated flows. With the works largely taking place during Durban’s wet season, rainfall and flooding were responsible for frequent work stoppages when the site was flooded but major erosion and downstream flood damage were prevented.

Conclusion

The lateral support and piling works could not have been completed in the specified time frame without the value engineering offered by Franki. “Although the products offered were not, in themselves, necessarily new or innovative, they were part of innovative and inventive engineering solutions which met the demanding requirements and ensured that this project could meet the client’s expectations in terms of safety, time, cost and technical competence,” says Franki’s Paul Pearce.

He added that the success of the project depended to a large extent on the co-operation of all involved. “The client was open to suggestions and by allowing adequate time for tender, design review and incorporation of changes, the right solution was found to the benefit of all. The on-site management of the different disciplines was also critical and without the buy-in of the piling, earthworks and building contractor, the timely sequencing and completion of critical sections could not have been achieved,” he concluded.

All critical piling handover dates were met with non-critical elements being completed in line with the provision of access and without any delay to the overall programme.

 

 

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Bridgette Macheke
MoonDawn Media & Communications

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