Highway collapse A41 Christleton
In July this year a section of the A41 collapsed leaving a large hole in the road and complex investigations have taken place to establish the cause of the collapse.
To protect motorists, pedestrians, and the road itself from further damage, Cheshire West and Chester Council’s Highways team quickly closed the affected section of road and installed a set of temporary traffic signals. The traffic signals have been manned at peak times to manage queues.
When the Council’s contractor carried out excavations a hole over 2m deep was found under the surface. Remedial work was carried out to prevent any further damage to the road surface and to support the surrounding area.
During the excavations water was found to be flowing into a brick sewer chamber, maintained by Welsh Water. A camera survey of the sewer pipeline also showed that water was leaking into the sewer in a number of places, as well as into the brick chamber next to the hole.
Working with the Canal and River Trust (C&RT) and Welsh Water (WW) the Council dye tested the water in the hole and found it to be from the canal. This flow of water has, over time, washed material away from beneath the road forming a void that caused the collapse.
Once the cause was discovered, C&RT quickly mobilised a specialist repair team who reinforced the sides of the canal bank where water was escaping.
However, the repairs to the canal have reduced the flow of water but it has not stopped. Further dye tests and investigations have shown an additional leak in the base of the canal. C&RT engineers started work again this week to repair the source of this leak.
The reduced flow has also enabled Welsh Water to make a further inspection of the sewer and chamber to check its condition and see if any repair or replacement work would be required before the repairs to the road could take place. Fortunately, it appears that there is limited damage to the brick chamber and the sewer pipes, meaning only minor repairs will be needed. Once these are completed, repairs to the road itself can begin.
The Council’s Cabinet Member for Environment, Councillor Karen Shore said: “In addition to the work C&RT has undertaken on the canal tow path, geotechnical engineers carried out site investigations to determine if the void in the road extends any further than the hole visible in the surface.
“Initial results from these surveys and tests have revealed that the hole looks to be confined to what can be seen at the surface.
“Our Highways Team is currently putting together a programme of works to repair the void in the carriage and reinstate this section of road as soon as possible. More details of the schedule of works will be available on the Council’s website soon.
“I understand the frustration this work is causing and would like to assure residents that all the organisations involved are working hard to find a solution.”