A 315-metre bridge deck that can raise HS2 trains used to be slid over the M6 highway in a 17-hour operation on Saturday 13th December with out last the street to visitors underneath.
It used to be the 3rd and ultimate slide in a three-stage procedure to collect and set up the east deck of the M6 South viaduct.
Whilst the former deck slide had required a weekend closure of the primary carriageway, the group – led via HS2’s major paintings contractor Balfour Beatty Vinci (BBV) – labored with Nationwide Highways to increase the ‘totally restrained’ procedure that allowed them to soundly slide the general segment above the shifting visitors.
It’s regarded as the primary time this method has been used on a UK highway.
The contractors, they to start with closed the M6 in a single day between Junctions 4 and 5 on Thursday 11th December to shift the viaduct relatively ahead via 12 metres. This used to be to be sure that each ends of the beam had been totally supported on concrete piers right through the primary slide.
The viaduct used to be then driven the remainder of the way in which around the busy highway on Saturday at a velocity of 13 metres consistent with hour, with best the M42 slip closed right through the weekend.
The operation way the challenge to build the M6 South viaduct has now reached the midway level. Over the following yr, the similar procedure can be repeated, with a parallel West deck slid into place along the primary one to hold trains heading south.
Caroline Warrington, HS2 Ltd’s head of supply, stated: “Alongside the HS2 path we’re pioneering new approaches to engineering and development to be able to ship extra successfully and with much less have an effect on on our neighbours.
“We consider this totally restrained slide used to be a primary for the rustic, however most significantly it way we’ve been in a position to chop in part the collection of occasions we’ve needed to shut the highway. I’d love to thank everybody who labored so onerous to make the operation a good fortune.”
The M6 South viaduct has been designed in levels, with each and every segment assembled to 1 facet ahead of being driven out over the highway, with the following segment added at the back of it.
In the newest section, the group moved the viaduct the usage of strand jacks with construction sitting on Teflon pads to cut back friction.
BBV challenge engineer Russell Luckhurst stated: “We’re all feeling an enormous sense of pleasure after sliding a 4,600-tonne viaduct into its ultimate place this weekend. The 3rd and ultimate slide of the East deck viaduct used to be delivered over a are living highway for the primary time in the United Kingdom, making this success much more particular.
“The use of this ‘totally restrained’ method intended we had been in a position to stay disruption to an absolute minimal. Our focal point will now flip against the neighbouring West deck viaduct, which can be introduced in more than one stages right through 2026, in addition to the East deck completing works.”
Each and every viaduct is shaped of a hole double-box construction fabricated from weathering metal. The metal boasts a herbal protecting layer of oxidisation which supplies it a function ‘rusty’ look and decreases upkeep via getting rid of the desire for normal repainting.
4 pairs of concrete piers strengthen the viaducts with the tallest one measuring 9.9 metres in peak. A 4.5-metre-high parapet can be put in at the facet dealing with Chelmsley Wooden to cut back noise and disturbance from passing trains.
The viaduct used to be introduced with 82 precast slabs already put in on most sensible of the metal construction. This will likely additional cut back the collection of highway closures at some point, to finish the viaduct deck works.
The structural design has been performed via BBV’s design three way partnership, made up of Mott MacDonald and Systra, with WW&P Architects.
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