studiot

Update pictures. There has not been sufficient progress to determine anything new. However it is clear that the items in the river at the base of the wall that were asked about are sandbags. Here is the site board stating that there was scour and that they will underpin the wall, but this is not certain. I am trying to see if the masonry below waterline has deteriorated. Lias is not the most durable of building stone.

A true pedant would include the third possibility of both. Thanks for the pic but Somerset has not been periglacial since the last ice age. https://www.google.co.uk/search?source=hp&ei=Y9x-W-OnLOTIgAab47uoBg&q=periglacial+environment&oq=periglacial&gs_l=psy-ab.1.4.0l10.932.3458.0.7670.11.8.0.3.3.0.446.1052.0j3j1j0j1.5.0....0...1c.1.64.psy-ab..3.8.1138...0i131k1j0i10k1.0.0qSFFbDNCZU We sometimes get clay heave due to clay expansion on taking up water after a (hot) dry spell or subsidence due to clay shrinkage in the dry spell. And Keuper Marl has a high clay content/ is a form of clay.

Thanks for the continued interest folks. The quick sketches may help. The river channel generally varies from about 15 metres to 25 metres in this area. At the weir it turns through nearly a right angle (about 75 - 80 degrees) and impounds a total of about 3metres of water. So the water flows from right to left behind the weir at the top of the diagram and from top to bottom once over the weir. There is a further offtake, through a sluice, to feed an old mill stream at the top left corner, from the pool behind the weir. The failed flank wall is at the left hand end of the sketch. As far as I can tell there is no concrete retaining wall behind it ie it is not a facing wall. The failure is on the outside of the 75 degree bend and the water flows much more slowly here, and shoals on this side, As previously noted in the first pictures. The inside of the bend sees the main flow and a boxed spillway takes this beyond the weir. Section AA shows the long bench previously referred to that supports the main weir wall throughout its length and terminates in flank walls at each end, the left hand of these having failed as detailed with a nearly vertical diagonal crack at the drop off from the bench. Yes, Ghideon, that is shown under your blue arrow and has currently been stanked off in the dry but is normally under water. I'm not sure if the object referred to by your orange and green arrows is original or something put there by the workforce temporarily. It is certainly in the position you might expect to see a scour pool from the water tumbling over the bench in the photos. But I also note that the water is at its most sluggish here and would expect to see scour pools more towards the other end (but don''t) As noted hopefully riverbed investigations are now proceeding and I will report when something is known. Klaynos this is the River Tone in Taunton.

Good questions but this is not in the (former) mining, earthquake or fracking part of Somerset. This is a near flat river flood plain at the lower end of its course. Without the system of weirs this river would be tidal. The ground is Keuper Marl on top of a layer of river gravel.

It's a nameplate screwed on the wall I can't get there to read it as it is old and corroded, but it says that some Lord Muck built/opened the installation etc.

You may have noticed I have been away on holiday.I went down last evening to observe progress and took some more photos. The investigation has not yet revealed the cause. During the last couple of weeks, they have completed the cofferdam and knocked a small hole into the crack. What can be seen is that the weir and the sound section of wall is sat on a concrete bench, now dry in the first new picture, taken across the river. The failed section is at the back and left of the picture. No movement is evident in this part of the structure. The end of this bench is shown in the new closeup of the failure. This also shows that coursing lines of the failed section suggest it has rotated anticlockwise relative to the section on the bench, which has horizontal coursing. However the coursing in the triangular counterfort section of wall is still horizontal. The wall is constructed from blue lias blocks. A few of these that have been broken out are lying in the bench, not shown in the picture. The lias appears sound. Removal of the blocks makes the crack appear wider (perhaps it has also been cleaned out). The removed blocks came from the upper part of the wall, so I'm not sure what information was gained there as there is no subsidence behind the wall. There is no evidence of investigation in the river bed yet.

I don't know what text you are using and not all textbooks bring out the differences btween Sn1 and Sn2. This extract from Geissman is particularly clear.

Yes some old human relic may be uncovered. I'm sure there are no natural cavities in the gravel and marl of the river bed, which is in the middle of its flood plain extending at least half a kilometre on both sides. Ghideon, I remember the refurbishment of the old (13 century) packhorse bridge in Trowbridge, which I underpinned in the 1970s. A surprise then was the old Roman oak foundations (piles and cross beams) that were in better condition that the stones of the walls (Bath stone). It was extremely difficult to remove these oak foundations, jack hammers etc just bounded off, unlike with stones.

Not often, perhaps once in 25 years or so. The wall has stood several hundred years. The failed section of wall appears to have gone down and moved to the left, parallel to the line of the riverwall, - downriver - both about 75mm. It doesn't seem to have rotated in any direction or displaced into the river at right angles to the line of the riverwall. The crack appears sensibly of constant width. One thing to note is that this side of the river is very shallow and slow running. Looking at the downstream picture you can see the gravel islands that collect on this side. This is surprising since the river scour will be least on this side. There is nothing to suggest the earth behind the wall has become active. If active earth pressure developed, it would be greatest at the bottom so the wall would have rotated outwards at the bottom.

Thank you for the reply. I don't know the answer, hopefully we will find out when they pump out the cofferdam. However the movement of the wall suggests one thing but the stability of the ground behind it suggests something else.

The upper case Pi is reserved in Mathematics for the continuous product (Like the sigma for continuous sum), although I have seen it written as a super large lower case Pi as printers are not always au fait with the Greek alphbet. The Rhind Papyrus from aroubnd 1550 B.C. offers the value 3.1604 but not in decimal but in ancient egyptian fractions.

You are the only one abandoning scientific rigour. Exodus does not contain the number 3.14. Indeed ancient hebrew numbers did not run to decimals at all. Even the decimalisation of the paragraphing in say the King James Bible is relatively modern. The modern decimal separator had yet to be invented in 1604! However the Bible does indeed contain a pretty accurate figure for Pi, considering its origin date, in the Old Testament. I Kings VII 23 So be Scientific and get your fact straight before you hypothesize.

Would anyone care to hazard a guess and say why?

Oh My God I will have to say Oh My Pi in future. But it doesn't have the same ring.

The OP very clearly started this thread to discuss space. This attempt to hijack it to discuss time has been reported at the original hijack.

So you don't exist either then? Weren't you the one who ran away from answering my question about shadows? I am still waiting for that answer.

Hello Martin and welcome to SF. I will be interested to view your first scientific thread or comments. Meanwhile, the sandbox is for testing things such as presentation, Latex etc. The Lounge is the best place to introduce yourself. I suggest you private message (PM) a moderator and ask him (or her, yes we have lady scientists here too) to move it. Be warned that you have 5 posts total on your first day (excluding the pm) - this is not personal, it was brought in to combat spammers and works quite well. Cheers

The Postman : David Brin Lord of the Flies : William Golding On the beach : Neville Shute

Greybeard https://en.wikipedia.org/wiki/Greybeard

This could involve you in a debate as to whether bitcoin is material or non material.

I too like Strange's analogy +1 I also note some unnamed member voted me a -1 for giving two other members positive feedback. Stand up and be counter Sir or Madam.

What a good idea, +1, shame it doesn't work on my PC. However you have prompted me to look further. Hold the windows key down and hit the letter R.Type charmap.exe into the runbox. Choose your symbol(s) Choose copy Paste them in here. ∆ √ Note you can also then select and increase font size, as I have done to 36 in the examples.

Like both the sober detail from Mordred and the tongue-in-cheek soundbyte from MigL. +1 apiece. Long may the double act continue.

Maybe it doesn't like your spaces, MathJax won't parse your code for me. However [math]y = \int {f\left( x \right)} dx[/math] But you have to click on page refresh in your browser to get MathJax to activate. SF has stooped to the (low) level of other forums.

I know that. That is why I said that you did not say it. It is also why I did not accuse you of it, or contradict you. What I think you mean is that some truths are absolute. In which case one counter example is insufficient. But I did observe that you chose a poor example in mathematics since it is not about about 'absolute truths. And I gave an example of the mathematics of where the truth varies according to the conditions. It would be really nice if you could be bothered to acknowledge my posts properly and accurately, especially as they seem to be the only ones offering you any support.