Polypipe’s
Ridgidrain pipe and ‘top hat’ connectors deliver speed and cost benefits to
drainage works on the M4 smart motorway.
Taylor
Woodrow has installed over 3200m of Ridgidrain and 1000 ‘top hat’ chamber base
connectors from Polypipe Civils & Infrastructure, the UK’s leading
manufacturer of sustainable drainage and water management solutions, as part of
its M4 smart motorway works.
The
flexibility of the Ridgidrain system led to savings on installation time and
materials when compared to other options.
“The
versatility of Ridgidrain when delivered on-site helps our teams to make
maximum use of the materials at their disposal,” says Taylor Woodrow engineer
Guy Miller. “Ridgidrain allows for pipe sections to be cut to length to meet
the onsite requirements without affecting pipe integrity or the ability to link
it with the other components of the motorway’s surface water management system.
This saves time and provides us with the assurance that the installed system
will stand the test of time.”
Speed of
installation is an important factor, as one of Highways England’s highest
priorities is to minimise disruption to traffic and communities during works.
Polypipe’s ability to supply the required amount of Ridgidrain within a tight
timeframe also influenced Balfour Beatty Vinci JV decision to use the system
for the central reservation drainage.
Highways
England will invest £848m in total to create the new smart section of the M4
between Hayes and Theale, the longest in the UK. A joint venture between
Balfour Beatty and VINCI subsidiaries VINCI Grands Projets and Taylor Woodrow
is delivering a package of smart motorway upgrades which includes the M4
between junctions 3 and 12. The works, which involves widening the motorway
from three to four lanes, rebuilding 13 major structures and deploying active
traffic management (ATM) technologies, are designed to increase traffic
capacity – currently running at 130,000 vehicles per day – on the capital’s
transport critical primary western route
Balfour
Beatty VINCI JV started work on the two-mile section of the M4 between
junctions 8 and 12 in October 2018. Upgrading the drainage is an important part
of the works, as rainfall continues to increase all year round.
Ridgidrain
pipe is a versatile non-pressure surface water and subsurface water
structured-wall carrier drain system. Manufactured to nominal stiffness SN6,
its high crush resistance and strength-to-weight ratio makes it ideal for
stormwater applications where high traffic loads are expected. Integral sockets
for easy pipe alignment make installation rapid and straightforward.
With
plain-ended pipes available in diameters ranging from 100 to 600mm, and
internally-socketed versions from 400 to 900mm, Ridgidrain is the first
twinwall surface water drainage system with Highways Authority Product Approval
Scheme (HAPAS) up to diameters of 900mm
Connecting
the plastic subsurface network with concrete drainage elements on the surface
of the motorway, the bespoke flange ‘top hat’ chamber base connectors act as
inlets and conduits for the slip-formed concrete slot drains sited along the
central reservation. They get their millinery nickname from their appearance
when slotted over the end of Ridgidrain pipe.
John Moss,
Business Development Director, Polypipe Civils, adds: “Polypipe offered Taylor
Woodrow a better economy of scale than other available systems for this
project. The value proposition from Polypipe was strong as we helped to
optimise the efficient use of materials on-site, proving to be more versatile
and adaptable to the ground conditions and section length requirements. This
adaptability includes plastic’s ability to flex with ground movements,
eliminating the need for rocker and stub pipes when entering and coming out of
chambers, as would be required with traditional materials”.
Polypipe is
also providing a combination of Ridgidrain and manufactured top hat connectors
with bespoke flange connections for the next phase of the project which
involves installing surface water drainage along the grass verges flanking the
carriageways. The M4 smart motorway works are due to finish in 2022.
