Foundations specialist Roger Bullivant is reinforcing its attack on the civils infrastructure market armed with a precast concrete pile able to take both tension and bending. David Hayward reports.
Maverick is one of the adjectives foundations contractor Roger Bullivant readily accepts the company has been labelled with for much of its 40 year life.
“We were seen as a contractor pushing the boundaries and codes to solve our clients’ problems,” concedes technical director John Patch. “We were the few-rules specialist not willing to toe the line in our search to come up with the best value engineered solutions.”
It is a description seen as neither dangerous nor derisory – just outdated. And the company is now firmly steering a new course.
The turn of the new millennium heralded the start of Bullivant’s new professional approach.
And its recent acquisition by major geotechnical specialist Soletanche Bachy has provided the firm with additional opportunities.
Long dominant in the house foundations market, the still fiercely independent contractor is renewing its attack on the civils infrastructure domains of road, rail, wind turbines and even nuclear.
And to reinforce its marketing drive, the company has added a novel new pile to its foundations options.
As the inventor of the segmental precast concrete pile back in 1985, Bullivant has launched a state-of-the-art engineered design complete with an imported jointing system that can accommodate both tension and bending moment loading.
The company claims that a doubling of its civil engineering expertise, expansion of its three design offices and four client- facing decades of providing demanding house and factory owners with economic foundations, will help to give the contractor a head start on its civils rivals. Bullivant has already doubled its infrastructure turnover to £8M and aims to double it again by 2015.
“We will still question codes and risk factors but only to approach the boundaries rather than push through them,” Patch explains.
“We aim to achieve high standards of technical sophistication allowing us to maximise value engineering for our clients.”
As a pioneer of engineered foundations in the housing sector, Bullivant saw the advantages of replacing strip foundations – even in good ground – with short precast piles.
Less concrete, minimal excavation, reduced labour and improved construction speed added up to a sustainable and economic solution.
It is these very practical observations, plus the challenges of dealing directly with individual end-users’ clients, that the company plans to bring to the public sector dominated infrastructure market.
“Our pile is one of the first to obtain this European certificate and we reckon it will prove the most economic precast concrete foundation design of its type anywhere”
John Patch, Roger Bullivant
Bridge foundations, rail platform extensions, embankment stabilisation and wind turbine bases head the list of structures that could benefit from engineered, sustainable precast pile solutions, Bullivant argues.
And to make such options the most economic around, the company is now using a high quality Finnish pile joint that converts its standard, long proven, precast piling system into an engineered design capable of accepting a range of imposed forces.
The Emeca joint is formed of matching socketed steel plates fixed to the ends of otherwise standard 4m and 6m long precast pile sections.
The square plates are quickly mated together and locked with hammered-in steel pins as sections are added to the driven up to 45m long segmental piles.
Bullivant claims its new engineered pile can be installed as fast as standard ‘Collet’ versions jointed with more simple single rebar and springgrab connections.
The significant difference is that the conventional Collet pile, taking only vertical compression loading, is replaced by an Emeca jointed version that can accommodate both tension and full bending moment forces (see box).
This allows the pile much more extensive use in the demanding civils market that the company is now attacking.
And to help secure its credibility, 18 months of company research and testing has just resulted in the new pile being awarded a coveted CE marking.
A CE mark is the Brussels demanded accreditation that a wide range of construction products will need by summer next year to allow their continued use in the European Union.
“Our pile is one of the first to obtain this European certificate and we reckon it will prove the most economic precast concrete foundation design of its type anywhere,” Patch asserts.
“In the increasingly challenging civils market the only way to win work is to be cheaper than your competitors.”
Bullivant’s steel plate Emeca joint can be cast into any of the company’s standard 1.5m to 4m long precast concrete segments.
The joint’s four socket connections are each secured with side-installed locking pins hammered into position as soon as sections are mated, extending the pile while being driven. Total pile length can be up to 45m with most sections joined by standard single rebar spigot connections and only upper segments needing the engineered
Emeca joints. The resulting up to 300mm square pile can then accept a maximum tension load of 230kN and a full bending moment of 32kNm. The contractor claims a multisection 20m pile can be installed in just 20 minutes.
In comparison with conventional concrete or steel cased piling, the segmental system – with reduced transport costs, crane-free installation using only a low head piling rig, plus remote operation requiring just a two-person team – is claimed by Bullivant to be twice as quick to install and offer up to 10% cost savings.