Highways England has announced that work will be carried out to improve sections of the M11 and drivers are being warned to expect delays around Huntingdonshire.
Around 39,000 kilos of a new expanding grouting product will be used to strengthen embankments along the section of road which is used by 40,000 drivers each day. The expanding chemical will be used fill in underground voids at the Girton interchange in Cambridgeshire, where the M11 meets the A14, which were discovered following routine surveys. Monitoring of the embankment has been carried out since November last year. They are believed to have been caused by groundwater damage due to the recent extremes in weather, especially unseasonably heavy rainfall which caused unexpected water erosion. If left untreated, they could cause the drainage system to deteriorate further, which could harm the embankment, and potentially then the M11 itself.
Traditionally, the highways agency would have closed the M11 completely in order to dig up to six metres of earth beneath the road, and then refill in layers with a concrete mixture. When that had hardened off, it would have needed to resurface the motorway and reinstate all the drains. The new material works differently by expanding underground to fill the voids more quickly and with less disruption to traffic.
Highways England project manager Karl Brooks said: "Safety is paramount in the work we do at Highways England, so we need to complete this work as swiftly as possible.
We need to complete this work at Girton before the colder winter months set in, as such weather could cause further deterioration, so we're keen to remedy the voids before that happens. We ask drivers to be patient while we're working as we appreciate this work is likely to cause some disruption in a busy area, though the work we are doing is essential maintenance to ensure safety, so please plan your journeys and drive appropriately through our roadworks."
Junction 14 of the motorway has been reduced to one lane running past the junction during the day time, with closures overnight between 9pm and 5am. There is already a 50mph speed limit in place here, reducing to 40mph, as part of our work to improve the A14 between Cambridge and Huntingdon. There were four nights of closures earlier this week for preliminary works, with drivers heading westbound diverted to take the A428 and the A1198 to re-join the A14 at junction 24. Eastbound traffic will be diverted to continue on the A14 to junction 30, then exit and return."
Full work will start on September 24, taking around three weeks, with engineers drilling boreholes into the embankment up to three metres deep, both horizontally and vertically, before injecting the unique filling material designed to stabilise and reinforce the ground there. In addition to this, drainage works will be completed to prevent further erosion.
The work is being completed in addition to the £54.2 million Highways England has committed to maintaining the East's roads over the 2018/19 financial year, complementing the £61.4 million of maintenance work the organisation either completed or begun in the last year.
The team is working closely with colleagues completing the new £1.5 billion A14 Cambridge to Huntingdon link road, upgrading 21 miles of the A14 to three lanes. This improved A14 will cut journey times by up to 20 minutes, and is on target to open to traffic in 2020. Both teams are sharing road closures to maximise productivity while minimising the impact on road users.