retaining wall brick Wall supporting highway

[David126]

Back in the 1930's highways widened the pavement to 19ft.  My semi was built in 1937/38, the property is below pavement level with a retaining wall of approx 2m to the foundation. 
The wall is approximately 8M long, generally in the order of 0.23m thick above ground level. Its thickness below ground level is not known.  

There is a brick counterfort built (at a later date) against the rear face of the retaining wall behind the centre-left pillar and alongside an earlier (and possibly original) approximately
0.23m square brick pier shown below.

 

The footing to the retaining wall is approximately 0.1m thick concrete; the underside of which is approximately 0.8m below ground level at the rear of the wall and with a projection from the rear face of the wall of approximately 0.065m.

 

Extracts of the reports conclusion from my consulting engineer says:

We are of the opinion that the wall has rotated due to inadequate foundations – the toe at the rear of the wall being of insufficient projection, resulting in excessive pressure on the
underlying ground under the constant pressure from the retained earth, and greatly exacerbated by periodic vehicle-related surcharge loading on the footway. Rotation and bowing of the wall has also caused the formation to the footway to drop and the consequent repairs to the surfacing have most likely compounded the issue. The effects of root action – in terms of mechanical damage and also very likely moisture variations in the predominantly clay subsoil due to water demand of the Linden/Lyme tree - are also considered to be a significant contributory factor to deterioration and movement of the brickwork.

 

So... the council refuse point blank to have anything to do with the wall, despite it supporting the pavement as it was probably constructed to provide benefit to the landowner!!!
 

My quandary is what to erect to stop the wall collapsing?   Losing a metre of land to place gabions is not ideal, but may be the most cost effective solution. 
This is the proposal from the engineers, which suggests it may be beyond my skills to erect.   Anyone with any thoughts?
Retaining Wall Report.pdf
Retaining Wall Report.pdf

[markc]

My thought …. Do nothing, allow it to fall and then Highways or local council will have to sort it out.

and/or notify council that their wall is dangerous and you are concerned for you and your families safety as well as road users etc.

[Temp]

3 hours ago, David126 said:

Back in the 1930's highways widened the pavement to 19ft.  My semi was built in 1937/38, the property is below pavement level with a retaining wall of approx 2m to the foundation. 
The wall is approximately 8M long,

 

I think you need to find out which came first. If the ground was leveled and retaining wall built to allow your house to be constructed then unfortunately I think its your responsibility. If the road was widened and the retaining wall constructed after you house was built then you might have a case.

 

Is there anything in your deeds? Are neighbours affected? Have Highways Dept inspected the wall?

 

https://www.devon.gov.uk/roadsandtransport/maintaining-roads/managing-the-network/retaining-walls-and-bridges/

 

Quote

Most retaining walls, which directly support the highway or support land carrying the highway (‘highway retaining walls’) and are within the highway boundary, are maintained by us.

Occasionally such retaining walls have been built by adjoining landowners to create a more level site and so afford more useable space, for example, for a mill. These are generally owned by and should be maintained by, the landowner. Whilst this cannot be insisted upon by the Highway Authority, unless covered by an agreement, the highway does have a right of support under common law and this can be used if the wall starts to collapse.

 

 

So if you allow it to fall down they might be able to send you the bill to fix it.

 

What does your house insurance cover? Sometimes they won't cover retaining walls unless they have been adequately maintained.

 

 

Edited August 26, 2021 by Temp

[Mr Punter]

For some reason I was unable to open the PDFs but you should seriously consider the recommendations of your consulting engineer.

 

They may be able to design some structural steel solution.

[markc]

Just re looking/reading this. So the wall is supporting the pavement/road.

does it look like the retaining wall wall built to allow the house to be built, or was the wall built solely for the purpose of supporting the roadway regardless of the house being there?

do your deeds mention this boundary?

if you are liable for the support of a highway then your insurance company would be the first people to contact as you cannot undertake this work yourself.

[David126]

Thank you all for the thoughts and advice.

The insurance cover includes legal, but apparently this is to defend any action against policyholder. 
If the wall collapses, and is deemed mine, any cover will be reduced because it was not maintained!!

Regarding which came first, our deeds are only for the plot of land, shows the boundaries but no details of the building.  
The plot shows proposed road widening which may mean that nothing had been done, but stops development closer to the road for 4 houses.  In 1937 the pavement may not have been much more than dirt, judging by some old photographs of the area.
The council are clear that they did not build, and will not adopt, the wall as it was probably built for the benefit of the development.
All boundary walls and fences are deemed to be the responsibility of both ourselves and adjacent landowners.

I have asked the council what the building regulations for constructing a wall to support the highway were in 1937 and, as the wall did not meet the specs (engineer confidant that the amount of rotation clearly shows it was inadequate), what they suggest as it should have been inspected and passed as suitable.

The engineer is suggesting gabions 1M square across the 8M, this will reduce my useable land, by more than a metre which is in front of windows.  But may be the way to go as it does nor require deep excavation which may find cables and pipes with all that that entails. Have re-attached the proposal.

Retaining Wall Strengthening Proposals.pdf

[Temp]

Presumablyhe reckons it cheaper to reinforce the existing wall with gabions rather than rebuild it all.

 

Only other thing I can think of is to see what if anything can be seen on old maps or aerial photos. 

[Brickie]

Would it not be possible to build a battered  retaining wall in front of the existing?You’d lose some square metreage as you would with Gabions but retain most of the light to those windows.