Are these (non railway) earthworks safe?

[PaxVobiscum]

Having been impressed by the efforts that Network Rail have made recently on the design and construction of earthworks (on the Settle and Carlisle line and the Borders Railway project and other places), I am bemused by this recent embankment work at the site of a new roundabout constructed to enable access to new housing. I know little about civil engineering, but it doesn't look very stable in the long term to me. Cutting round the base of a 132kV pylon at that angle seems unwise.

Any professional opinions?

 

[Clip]

Looks fine to me. is it only one sided or a proper island? Im guessing National Grid wouldve signed off both the RA & MS for it to be like that so Id say its safe.

Or for a better idea of its strudyness go give it a kick

 

[PaxVobiscum]

It's somewhere between 90 and 180 degrees of the circumference.
Heavy rain over the last few months has washed away some of the face already.

It looks to me rather like the kind of 'natural angle' at which railway embankments settled themselves when first constructed, but I gather that this is now viewed as not good enough depending on local conditions and drainage etc.

Quite a lot of cars and construction traffic use the road and it is within 150m of a busy freight and passenger line.

 

[Haydn1971]

Embankments / Cuttings in current design practice are typically 1 in 2 - anything steeper is likely to need some help with geotechnical work - ground pinning, reinforcing materials or some form of retaining structure.

I'd suggest that on the face of it, I wouldn't like to be standing close during or after heavy rainfall

 

[455driver]

Have a look next month, if its still there then its safe, if it is missing or leaning over then it isnt!

Thats my (un)scientific method!

I have to admit it doesnt look very safe.

 

[Yew]

It does look a bit steep. Personally I would have been looking to add wire cages full of stone as a retaining wall

 

[455driver]

How far from the edge is the pylon?
From such a low angle it is difficult to see!

 

[PaxVobiscum]

How far from the edge is the pylon?
From such a low angle it is difficult to see!

Oh, excuse me while I shin up the next pylon along for a better view!

As far as I remember, the pylon is closer to the edge facing the camera (and the slope is a bit steeper) than on the right side of the photo.

To construct the roundabout, the builders had to bulldoze away a big chunk of a hill and were constrained by the previously existing road alignment which might explain why the present new road has to come so close to the pylon.

I'll have a good look next time I pass (assuming it's still there of course).

 

[John Webb]

The pylon legs will be bolted to some form of foundation, such as piles driven into the ground, which makes it a little less dependent on surrounding soil. But as Clip says, the grid people will have been consulted!

 

[PaxVobiscum]

Looks fine to me. is it only one sided or a proper island? Im guessing National Grid wouldve signed off both the RA & MS for it to be like that so Id say its safe.

Sorry I'm not quite in the loop there.
Could you explain RA (Royal Artillery?) and MS (Marks and Spencer?) for us non- (but I trust not un-)civils? TIA

 

[455driver]

Oh, excuse me while I shin up the next pylon along for a better view!

Thats okay, I was just curious if you could give us an idea, 10ft, 20ft etc.

 

[bronzeonion]

For something that tall it would have deep concrete piles so it doesn't fall over so I can't see a problem

 

[PaxVobiscum]

For something that tall it would have deep concrete piles so it doesn't fall over so I can't see a problem

I can see that, but surely it would be unacceptable for the earth embankment to collapse on to the road in heavy rainfall, or for that matter for (at least some of) the concrete piles to become 2m shorter and the pylon simultaneously to become 2m higher?
--- old post above --- --- new post below ---

Thats okay, I was just curious if you could give us an idea, 10ft, 20ft etc.

You asked a sensible question there and I didn't give a proper response because I went for a smarta**e answer instead. (Hey - who put the truth drug in my Friday night Tempranillo?).

 

[Bevan Price]

A lot will depend on the material, and how effectively water drains out of it. It is only likely to be unstable if water accumulates and it forms a watery slurry, like some coal mining waste.

 

[DaveNewcastle]

RA = Risk Assessment
MS = Method Statement
(all essential parts of a CDM compliant worksite!)
CDM = Construction Design Management

Anyway, looking at the insulators, I can see that this pylon is on a straight line between its neighbours, and so, in the absence of wind, there are no lateral forces to consider. Also, the effects of the cables (weight, contraction, etc.) will be equal on either side. Consequently, the ground is only required to provide vertical support, plus the lateral resistance to wind.
For that reason, I wouldn't expect much of a land island would be necessary around the pylon's base - but the island that is necessary would have to remain stable in all environmental conditions incl. rain water, freezing, drying and cracking soil.

 

[PaxVobiscum]

Thanks DaveNewcastle for answering my acronym and vector based concerns so well (there I was still thinking that a CDM had something to do with a chocolate reward). Is there no limit to your expertise - what a mine of information!

My concerns are now much alleviated thanks to all they answers received (and I will still have the photos to sell to the popular press should all the reassurances prove to be wrong).

 

[Crossover]

....what a mine of information!

Let's hope there's none of them around

 

[PaxVobiscum]

Let's hope there's none of them around

Now that you mention it...