Walling research at Bath University

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Walling research at Bath University

Postby Chris Stephens » Fri Sep 07, 2007 5:00 pm

Really valuable work is being done at Bath with Richard Tufnell leading the DS wall building. So far the results have shown drystone retaining walls to be much stornger than the engineers expected. The work continues

Pictures and video clip at

http://www.bath.ac.uk/bre/projects/dsw% ... st%201.htm


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Postby stonedyker@talk21.com » Fri Sep 07, 2007 6:30 pm

Can we have some stats on the rock used, the construction specification and by how much it exceeded expectations?
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Walling Research at Bath University

Postby Chris Stephens » Fri Sep 07, 2007 7:44 pm

The stone was a "Cotswold" limestone but I can not tell you the initial results in any detail. These will be published eventually but the work is still at an early stage

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Postby Tracey B » Sat Sep 08, 2007 8:27 pm

It will be of no surprise to members that a dry stone wall is 'stronger than the engineers expected'. The integrity and ingenuity of the structure continues to amaze and delight me even more the longer I am walling. I was very interested in the test photos. In the second picture when the wall had been put under pressure it shows the weaknesses created where there is a running joint over more than two courses....no disrespect to the waller intended here, merely observation. I would like to know more about how they came to select this stone to do the tests with.
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Bath University Research wall

Postby Chris Stephens » Sun Sep 09, 2007 8:49 am

Dear All

This is as much as I know.

The stone was supplied by Angus Davey of Grange Hill quarry. Angus and the Quarry are well known down here, are corporate members of the DSWA and supporters of the Cotswold branch. We are all familiar with the stone which is excellent It is a ‘blocky’ oolitic limestone, almost a freestone that splits nicely. I do not have crushing strength or Youngs or shear modulus figures.

The actual construction team comprised Richard Tufnell, Ewan Ramage and Andrew Ramage. Richard Tufnell, is master craftsman (DSWA certificate holder). Richard is well known internationally and worked with Professor Peter Walker as an ancillary part of work being carried out at the Great Monument of Zimbabwe in the early 1990’s. He has built major retaining walls in a number of countries, in particular, the USA. . The whole idea was that the wall section would not be of mastercraftsman standard but typical of roadside retaining walls built 100 + years ago which do have significant running joints (at least down here!!!). Even so it was much stronger than expected. You don't have to convince me about this The work is being undertaken, amongst other reasons, to help promote the craft to a wider body of professionals such as civil engineers who think DS retaining walls can only be replaced with reinforced concrete. They are only going to change their minds by dry stone wallers producing well thought out research projects such as this

Members of the DSWA are most welcome ( as I was) to come and see the work and to chat to both the wallers and research team.You can e-mail Richard for further details on DrystoneUK@aol.com as he has recently moved to France his Scottish phone line is no longer current.

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Postby stonedyker@talk21.com » Sun Sep 09, 2007 12:40 pm

Thanks for the detail Chris,

I too was surprised to see so many running joints in the wall and the way it ''unzipped'' but was happy to read that the wall was built to a lower standard. Hopefully they will try the same test with basalts, granites and the like.

Few of us have 'crushing strength' and make do with what we have but maybe some of the ladies have 'Youngs or shear modulus figures'.
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Strength of walls

Postby david perry » Mon Sep 17, 2007 11:43 am

An interesting test. Again like many other wallers I'm not suprised at the strength of dry stone walls. Here in the SW of Ireland there are many drystone walls and many walls - mainly around houses - built with either concrete blocks in the centre and faced both or one side only using cement mortar. Drivers regularily collide with them. The concrete walls fall over. I've examined a number of 'hits' by vehicles on drystone walls. In one example a tractor reversed into a wall and the towbar dented the wall by simply pushing the stone it hit into the wall. There was no damage to the other side as no doubt the stone had pushed past its neighbour or pushed the fill aside. In another example I saw only yesterday, on Cape Clear island, someone had collided head on with an old wall around the church. The wall had been pushed in on the side it was hit and on the far side the wall showed only the slightest bowing. The wall still stood firm with only minor damage to the cope stones which were cemented in place. Judging from the wreckage around the site the car came off rather worse.
No doubt other members have seen similar examples.
I just like stone!!

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Re: Walling research at Bath University

Postby law88 » Fri Feb 04, 2011 3:35 pm

hi
at the moment i a carrying out my fianl year dissertaion at bath uni on the effects of weathering and construcion styles have on the sliding stability of dry stone retaining walls. Due to time constraints etc this is mainly looking at walling within the bath area (drivable) could anyone recomend any particuarly interesting retaining walls int eh area that i could go and look at (varying ages)? they need to be acsessable so i can take measurements etc.

thank you
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Re: Walling research at Bath University

Postby Nigel » Fri Feb 04, 2011 7:15 pm

Just to say I am scheduled to build about 20m of new retaining dry stone wall about 30 mins away from Bath this Summer and later in the year will be building a 1.5m Ha ha possibly 100m long at the same location.

Let me know if any of this would be of any help to you, I am always happy to talk about this, also happy to check my calculations for the size and structure of the wall needed.

Good luck with the research. I am 100% sure that your findings will favour the correctly built dry stone wall over breeze blocks not only in durability but in the total cost of ownership.

Best wishes,

Nigel.

Would just add that the wall failure clip looks more like a wall being pushed over clip. Poor wall.

Just noticed that this project was due to end back in 2009
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Re: Walling research at Bath University

Postby law88 » Tue Feb 08, 2011 1:00 pm

hi nigel
this is due this yr! (2011) and is and is futhur to previous research carried out.
my dissertaion is due in may so that might be too early for you. but thank you for the offer, i will pass this information onto my supervisor as he may be interested in what you are doing.
I am sure it would be useful to talk to you at some stage in the near future.
Thank you very much.
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Re: Walling research at Bath University

Postby Nigel » Tue Feb 08, 2011 5:55 pm

law88 wrote:hi nigel
this is due this yr! (2011) and is and is futhur to previous research carried out.
my dissertaion is due in may so that might be too early for you. but thank you for the offer, i will pass this information onto my supervisor as he may be interested in what you are doing.
I am sure it would be useful to talk to you at some stage in the near future.
Thank you very much.
Laura


Its a pleasure, Hope I can help.
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