Strengthening Cuttings and Embankments

[GRALISTAIR]

Network Rail said their first priority is to do a full risk assessment of the cuttings/embankments of places most at risk for landslips etc. Obviously a laudable aim. I am not an expert on Geo-Engineering but what would it entail to make less risky? I assume a possession would be needed at some stage -possibly more than 1 and then use of Geo-Textiles and other drainage and vegetation management.

Am I correct in my thinking?

 

[Philip Phlopp]

Network Rail said their first priority is to do a full risk assessment of the cuttings/embankments of places most at risk for landslips etc. Obviously a laudable aim. I am not an expert on Geo-Engineering but what would it entail to make less risky? I assume a possession would be needed at some stage -possibly more than 1 and then use of Geo-Textiles and other drainage and vegetation management.

Am I correct in my thinking?

It's impossible to say - each and every site is different, both in terms of geology, soil mechanics, water table and the interface between the railway and the surrounding area. Two pieces of railway with very similar appearance may require vastly different works and one site may require few or no possessions, the next site may require a large blockade or months of weekend closures.

 

[GRALISTAIR]

On the Preston - Blackpool scheme, in most places they did not just cut the trees down but they also put rings of poison in the stumps so that further growth would not occur but also meant they did not have to go through the horrendous job of digging all the stumps and roots out.

 

[mcmad]

broadly is likely to mean regrading of such slopes to a more 'stable' angle potentially with stone reinforcement at toes and better drainage. Potentially issues around lack of land to regrade requiring more 'engineered' solutions. Expect to see a distinct lack of vegetation on slopes going forward.

 

[InOban]

Surely the trouble is that 150+ years ago embankments would have been built with whatever was available locally. And the records of what was used may be sketchy. Our understanding of geotechnics has moved on since then.

 

[Philip Phlopp]

Expect to see a distinct lack of vegetation on slopes going forward.

I would expect to see a different variety of vegetation, with more emphasis on those species which aide in drainage, assist in slope behaviour and which have reduced potential for damage and derailment to rolling stock in the event of a failure. Wild flowers rather than dense trees, for example.

 

[eMeS]

Network Rail said their first priority is to do a full risk assessment of the cuttings/embankments of places most at risk for landslips etc. ...

I spend far too much time watching TV, and in particular TV about railways.
Recent TV programmes have emphasised how important landslip is on the Norwegian rail system, Italian Riviera Coast, and on the Canadian Pacific. The programmes emphasised the efforts being put in to control the embankments, cuttings, rockfalls etc. What gets emphasised on programmes about the UK rail system? Fare dodgers and football crowds. Perhaps there's a clue there as to where the different priorities lie...

 

[59CosG95]

I'd put Soil Nailing down as a likely solution, if I were a betting man.

 

[GRALISTAIR]

I spend far too much time watching TV, and in particular TV about railways.
Recent TV programmes have emphasised how important landslip is on the Norwegian rail system, Italian Riviera Coast, and on the Canadian Pacific. The programmes emphasised the efforts being put in to control the embankments, cuttings, rockfalls etc. What gets emphasised on programmes about the UK rail system? Fare dodgers and football crowds. Perhaps there's a clue there as to where the different priorities lie...

Oh I hear you. Frustrating as hell.

 

[najaB]

I'd put Soil Nailing down as a likely solution, if I were a betting man.

In some locations it might be. I've already seen what looks like it on the HML for example.

 

[Philip Phlopp]

Oh I hear you. Frustrating as hell.

I would suspect engineering works taking place at 2am on a wet and windy December morning, with our guys all waiting around for the wind speed to drop sufficiently for something to be craned, is unlikely to be particularly compulsive viewing at 8pm on Channel Five.

 

[GRALISTAIR]

I would suspect engineering works taking place at 2am on a wet and windy December morning, with our guys all waiting around for the wind speed to drop sufficiently for something to be craned, is unlikely to be particularly compulsive viewing at 8pm on Channel Five.

I know I do understand but it seems like we talk a good talk on STEM then don't walk the walk.

 

[Bald Rick]

I spend far too much time watching TV, and in particular TV about railways.
Recent TV programmes have emphasised how important landslip is on the Norwegian rail system, Italian Riviera Coast, and on the Canadian Pacific. The programmes emphasised the efforts being put in to control the embankments, cuttings, rockfalls etc. What gets emphasised on programmes about the UK rail system? Fare dodgers and football crowds. Perhaps there's a clue there as to where the different priorities lie...

Perhaps they have different production aimed at different audiences.

 

[Tophat69]

Drains to dewater the slopes, sheet piling the toe, amongst others mentioned here already.

Plenty of things you can do, but cost-effectiveness will the determining factor of what is used, especially on lower trafficked lines.

 

[GRALISTAIR]

Drains to dewater the slopes, sheet piling the toe, amongst others mentioned here already.

Plenty of things you can do, but cost-effectiveness will the determining factor of what is used, especially on lower trafficked lines.

Thank you for your first post. Welcome.

 

[Starmill]

Even from a casual examination of the industry press and Network Rail and train company publicity, one can tell that remidial work on embankments has been taking up a lot of time and resources nationwide at Network Rail for some years, both after a failure and when detected in advance. I'm sure that, unseen, routine inspection and mitigation work goes on regularly.

One article I read recently suggested that there were 100 to 150 incidents per year of lines being closed or disrupted in an emergency as a result of landslips. Some have been highly publicised in the past decade, especially at Harbury, between Watford and Kings Langley, the Settle - Carlisle line closure, and not long ago at Epsom, but there have been many that made mainstream headlines.

 

[Bald Rick]

Even from a casual examination of the industry press and Network Rail and train company publicity, one can tell that remidial work on embankments has been taking up a lot of time and resources nationwide at Network Rail for some years, both after a failure and when detected in advance. I'm sure that, unseen, routine inspection and mitigation work goes on regularly.

One article I read recently suggested that there were 100 to 150 incidents per year of lines being closed or disrupted in an emergency as a result of landslips. Some have been highly publicised in the past decade, especially at Harbury, between Watford and Kings Langley, the Settle - Carlisle line closure, and not long ago at Epsom, but there have been many that made mainstream headlines.

The life of a geotechnical engineer is quite a challenge at present.

Assessment, monitoring, detection equipment and the like help enormously of course, and will probably capture something like 99% of earthworks issues (at a guess). Fortunately most earthworks failures take some time to occur, and early signs can be spotted and acted on, enabling modelling to demonstrate when intervention is required and what type.

It’s the (say) 1% that is the problem, ie earthworks that have no history of issues and no sign of failure. And within that (say) 1% there will be a small fraction that fail suddenly, and within that group an even smaller proportion that fail suddenly in a way that poses a risk to train movements.

 

[Ploughman]

To my way of thinking there is at least 50 years worth of catching up on ignored drain maintenance.
Lack of investment and cost cutting being the root cause.

 

[Philip Phlopp]

It’s the (say) 1% that is the problem, ie earthworks that have no history of issues and no sign of failure. And within that (say) 1% there will be a small fraction that fail suddenly, and within that group an even smaller proportion that fail suddenly in a way that poses a risk to train movements.

The situation is further complicated if a train movement itself causes even a small percentage of those sudden failures to occur.

 

[JamesT]

I spend far too much time watching TV, and in particular TV about railways.
Recent TV programmes have emphasised how important landslip is on the Norwegian rail system, Italian Riviera Coast, and on the Canadian Pacific. The programmes emphasised the efforts being put in to control the embankments, cuttings, rockfalls etc. What gets emphasised on programmes about the UK rail system? Fare dodgers and football crowds. Perhaps there's a clue there as to where the different priorities lie...

My recollection of the first episode of ITV's Trouble On The Tracks was it involved a flooded line and the disruption that caused at New Street. They were also following the guys who went out to sort the drainage to get the line reopened.

 

[Swanny200]

But then different parts of the country have their own issues, parts of Kent look pretty with the chalk for example but heavy rain on chalk I would imagine would have a different impact as heavy rain on clay for example, I am not a geologist but I would assume one blanket measure would not do for the whole country or even a whole area.

 

[Ken H]

just seen the new pix here - https://www.railforums.co.uk/threads/stonehaven-derailment.207648/page-33#post-4722368

It looks to me that the landslip is actually a burn dumping large stones on the railway
This is different to a landslip
Similar problems closed the Grasmere-keswick Road after Storm Desmond, tons of material was dumped by flooded becks.
you only need a tree to block a culvert in a storm and you are in trouble.

 

[ChiefPlanner]

The very complex geology of the UK can be a challenge , and a simple route section of about 20 miles (say at the top of the South Wales valleys , to take a random example) , can have 4 -5 varying rock strata from coal measures to red sandstone to limestone. Each with varying characteristics. Add boulder clay , sand deposits , vegetation. (poorly laid earthworks by cost cutting Victorian contractors) , incursions from off the railway (Edge Hill not so long ago) etc.

This , of course , is not a new issue - there have been a wide series of dangerous landslides in the past , noteably one in January 1918 at Little Salkeld on the Settle line , where a passenger train was completely derailed with 7 deaths , but the route had been examined by the local PW inspector 5 mins before. (who had the misfortune of seeing it , but being unable to do anything)

 

[swt_passenger]

just seen the new pix here - https://www.railforums.co.uk/threads/stonehaven-derailment.207648/page-33#post-4722368

It looks to me that the landslip is actually a burn dumping large stones on the railway
This is different to a landslip
Similar problems closed the Grasmere-keswick Road after Storm Desmond, tons of material was dumped by flooded becks.
you only need a tree to block a culvert in a storm and you are in trouble.

There’s no watercourse marked on the OS map in the vicinity of that land slip.

 

[Ken H]

There’s no watercourse marked on the OS map in the vicinity of that land slip.

many arent, especially ones that only flow occasionally. especially if there is limestone.
and often unmade roads can turn into a river. There is a steep farm track near me that meets a minor road on a hill. That destroyed the track and dumped tons of stuff down the road in flooding early this year.

 

[Nottingham59]

There’s no watercourse marked on the OS map

It may just have been run-off from the adjacent field, during the intense rainstorm. On the old 6"OS map https://maps.nls.uk/view/74427603 there is a minor kink in the 400ft contour just about that location, which suggests there is a slight valley which would concentrate any surface run-off to that spot.

 

[najaB]

There’s no watercourse marked on the OS map in the vicinity of that land slip.

As @Ken H notes it's almost certainly not a full-time watercourse. This marker is approximately where the landslip covered the tracks, it looks like it's just a gully that occasionally collects runoff from the fields above.

 

[Ken H]

I use streetmap.co.uk to get OS maps.
can someone post a link from there to the exact crash location, please?

https://wtp2.appspot.com/wheresthepath.htm allows us to see OS and geological maps of the UK.

 

[Swanny200]

streetmap Think crash site is square 85

 

[Ken H]

Streetmap Think crash site is square 85

Thanks
can you use the move arrow facility to put the arrow at the site, and resent, please?