B4069

[Big L]

Anyone else seen this?

[Barkstar]

So who pays if it's due to inadequate drainage on private land causing the slippage or creating a sinkhole? There are temporary lights on the A34 between Congleton and the Alderley Edge due to half the road flooding if there is anything more than a shower. It would appear the problem is mainly due run off and I suspect even if the road's drains were sorted they would soon be full of silt from the run off in no time. Do authorities just pay up or do they seek restitution from landowners in such cases?

[Owain]

I like the "Seek alternative route" suggestion!

Translation: "You've all got satnav, so sort it yourselves".

[ellandback]

I will be impressed if that gets fixed in a year. The A6025 suffered similar (although by the looks of things, not as bad) damage following heavy rain a couple of months before the original lockdown, and has only just reopened.

We were also "awaiting a report from geotechnical specialists" (or something like that) and then there were a myriad of funding issues to resolve and then, after about 18 months, somebody actually came along and started trying to fix it ...

(Of course, there are now new roadworks and temporary lights at the other end of the road because we just couldn't possibly have managed to deal with that whilst it was already closed.)

[Rob590]

It also reminds me of the work that had to happen in Rothbury after the B6344 slipped in the 2012 floods. That cost upwards of £9million and was closed until 2016. Unfortunately, there have been further closures there for shorter periods over the last couple of years too due to further slippage and repairs. I can only imagine that this will be a similarly long and complex job.

[KeithW]

It looks as if it is at least in part a geological problem.

Geotechnical specialist Clive Edmonds told NCE that images of the damage - which show the road surface "heaved and then falling away in level" - suggest that "mass movement of the slope has been triggered probably by locally increased pore water pressure build-up in the slope profile leading to renewed landslide activity".

He added: "This sort of movement would account for the highly irregular switch-back look along the road alignment and cracking of the surface.”

Edmonds explained that the road “coincides geologically with an area where the Jurassic age Stanford Formation (limestone) appears to overlie/overstep the Hazelbury Bryan Formation (sandstone)”. Both of these are underlain by the Oxford Clay Formation.

[Chris5156]

Edmonds explained that the road “coincides geologically with an area where the Jurassic age Stanford Formation (limestone) appears to overlie/overstep the Hazelbury Bryan Formation (sandstone)”. Both of these are underlain by the Oxford Clay Formation.

Ah yes, that does explain it!

[bart]

"The Oxford Clay Formation" would be a great name for a rock band (no pun intended).

[skiddaw05]

Would the landslip have been exacerbated by live traffic (such as at Mam Tor)? If so it would be the highways authority (and not just drivers) who would have to seek an alternative route

[DavidB]

The B4069's landslip is the subject of the latest video from Jon of Auto Shenanigans: