It’s all too easy to publish to the internet, unless Conroy Maddox has been using your keyboard as I am sure all of the art lovers who attended the Turner Contemporary will understand.
Many thanks to the contractor Cardy Construction for chipping the chalk off of one of the foundations to a support pillar, that is part of the concrete structure of the arches, part of the Pleasurama cliff façade and sending me a picture.
I genuinely think that it is safe to walk on the cliff top footpath now, something I will be doing again.
Here is the picture and this is what they have to say about it.
“Dear Michael
As recently discussed please find the attached photograph of the exposed column foundation. The location of concrete highlighted in red extending below the excavation level passed the dotted line would indicate the foundations are built as described within the historic drawings. It would appear that the concrete was originally cast against chalk and not shuttered therefore causing the surface of the concrete to appear uneven. We have washed the concrete off as much as possible and driven steel rods into the foundation which appears to be of sound construction.
Regards,
Michael”
As recently discussed please find the attached photograph of the exposed column foundation. The location of concrete highlighted in red extending below the excavation level passed the dotted line would indicate the foundations are built as described within the historic drawings. It would appear that the concrete was originally cast against chalk and not shuttered therefore causing the surface of the concrete to appear uneven. We have washed the concrete off as much as possible and driven steel rods into the foundation which appears to be of sound construction.
Regards,
Michael”
This, like so many historical engineering puzzles, has a solution that probably involves practices that wouldn’t occur today.
What happened in this case was that having cut a slot about three feet wide and about three feet deep, going up the seventy foot high bare chalk cliff above, they got some poor chap to get in the bottom of the slot and dig a hole eight and a half feet deep in solid chalk.
I think this picture (I have put coloured lines on the original 1930s plan and sorry about the drawing of the bloke, my children are better at using MS Paint) explains what this is about.
Viewed from the side on.
The red line is the outline of the concrete pillar.
The green line the original line of the ground before the contractor dug out the ground next to the cliff about a fortnight ago.
The brown line about where they have dug the ground down to now.
The blue bit shows where the concrete block walls between the arches are.
Having solved one problem that is a mixture of industrial archaeology and civil engineering, like so many other things in life that leaves us with another problem and more questions.
Can anyone think of a way that they could have got the foundations in for the infill walls between the arches? The most they could be are nine inches thick, I think, not room enough for a man to get inside.
You can see from on the right hand side of Cardy’s photo that the virgin chalk seems to go right up to the bottom of the block wall.
Are there any foundations under the concrete block infills? If there are, do they extend down as far as the contractor has dug down? Are the concrete block infills tied to the pillars either side? In the simplest terms, is there a danger of block infill walls falling on the people working on the building site next to them?
I don’t know how far down you can dig a nine inch wide foundation trench in solid chalk with a shovel, but would doubt it is as far as the chalk has been dug down next to bottom of the block wall.
The pictures should all expand if you click on them.
Rather than hurl anonymous abuse at you and ignore and patronise you as some have done, Cardy took your justified concerns seriously. Cardy then replied in a polite, helpful and informative manner. Which has allayed our fears. Cardy has behaved like a gentlemen. It is a pity that some of the anonymouses were unable to to do the same. Especially those who are close to TDC, councillors even.
ReplyDeleteWhat a bizarre comment from John Holyer. Whilst I would agree that some of the anonymous comments questioned Michael's motivativation, it is rididculous to assume they must be close to TDC councillors. Since there was nothing to worry about, and anyone on or close to the council would have known that, what was there to defend.
ReplyDeleteSome people just cannot let things go without a farewell snide dig.
Anyway, well done to Michael for his perseverance and a victory for commonsense in the end.
John this is the fourth time I have reported a possible flaw with this façade structure to the council.
ReplyDeleteThe first resulted in no action, although it was promised by the council’s senior external advising engineer from the firm supervising the £1m repair for the council.
The second resulted in the council cutting out a panel and replacing it at a cost to us of £20,000, after the £1m repair had been signed off.
The third resulted in emergency action, removing lose bits and cordoning off the bottom.
Now this one and as you say Cardy’s have acted properly, but we now have the potential problem with the blockwork feature.
Here is the email from the council’s senior external advising engineer, I have removed his name.
“Subject:
RE: A sound foundation
Date:
01/02/2008 14:03:03 GMT Standard Time
From:
*******@******
Reply To:
To:
MichaelChild@aol.com
Hello Michael
Thank you for the photographs, I had a look yesterday at your area of concern, and you are correct in what you are seeing is a shallow foundation of concrete which has chalk below. This is only for the blockwork feature and is only exposed for a length of 5 metres approx. The critical element is the concrete portals, the base of which are deeper. I have asked ***** to place some anti weathering concrete against the exposed chalk to ensure no further weathering occurs.
Regards
*****”
I have written to the Cardy’s and the council explaining the potential problem and am awaiting a response.
Bluenote
I think you may have come in on this problem rather in the middle and assumed that this was a one off concern of mine.
I suppose the point of interest here is that while investigations as to the structural integrity of a structure are investigated you and me are allowed to walk where we could get injured.
The third possible flaw with this façade involved a lump of masonry weighing 50lbs falling from about 60 feet up, unto a public footpath, this was about two weeks after I reported the problem area to the council.
Quite soon after this they erected a fence around the footpath and removed some of the other lose bits.
The other area of significance is that while the council officers involved in this issue agree with me that it is dangerous to allow heavy vehicles onto the footpath above the façade, they have been promising me that they will do something about this for about two years now.
So I don’t think you could say that the council officers think there is nothing to worry about, with the election coming up I am not repeating what councillors of both parties have had to say about this structure.
Those at TDC and councillors did not know that there was nothing to worry about otherwise they would have spoken out sooner. Only when the contractor has exposed the footings was the position known, something TDC could have done a few years back when the development was being proposed.
ReplyDeleteMaybe TDC can now tackle the issues concerning the EA.
"It is a pity that some of the anonymouses were unable to to do the same. Especially those who are close to TDC, councillors even."
ReplyDeleteHow do you know that they are close to TDC if they're anonymous?
This comment has been removed by a blog administrator.
ReplyDeleteSee it was quiet simple all it needed was a bit of spade work to expose the footings. I cant understand why this was not done in the first place.
ReplyDeleteSorry 20.21 anonymous abusive personal comments towards other commentators are not permitted on this blog, I should also point out that I can make life more difficult for you on the blogs than just deleting abusive comments.
ReplyDeleteDon at the moment on the footings front it’s one all, Cardy’s have exposed one column with footings and one without, see http://thanetonline.com/cliff
ReplyDeleteRetired structural engineer and college lecturer.
ReplyDeleteDear Michael,
I have been reading the recent posted messages regarding the cliff at the old Pleasurama site with a professional interest and as the weather was wonderful this evening I took the opportunity to walk along the promenade, armed with my trusty binoculars.
I’m sure you’re aware of the difficulties trying to view the cliff face from behind the site hoardings; however I was able to stand at the gates of the eastern end of the site and inspect the columns and wall facings quite easily through my binoculars.
I noted the exposed column foundation from the photograph and comments kindly provided by Cardy Construction and would agree with the statement of the foundation being originally cast against the chalk excavation. This clearly shown in your useful sketch which depicts a method of excavation which was still in use in the late 60’s when forming drain headings in chalk and I’m sure many of your senior readers involved in civil engineering will have similar recollections and experiences.
With regards to the facing panels between each of the columns, you state concerns relating to blockwork panels? Whilst the panels to the Western end of the cliff are clearly blockwork those to the East appear to continuously poured concrete panels. This is evident by the imprint of the original shuttering boards used and which are still visible enough that to determine each board being approximately 6” in height. This would lead one to conclude that the structure was formed as a single concrete reinforced unit and as such would act in a completely different manner to a concrete frame with blockwork infill panels. The foundations to these panels were not visible however given the majority of the imposed load is catered for by the columns and in turn the exposed foundations the need for significant foundations below these panels reduces considerably, to the point that one could argue with adequate reinforcement between the column and the panels a foundation at this point could be superfluous.
I would like to commend Cardy Construction for the professional manner in which they have acted in the issues relating to the cliff and these recent concerns. Over my many years in the construction industry I have had the opportunity to be involved in numerous major projects both at home and abroad, it is very pleasing to see we still have professional and considerate construction companies such as Cardy in the industry. I intend to write to their office in Canterbury to express my appreciation of their efforts and professionalism.
In conclusion I would like to add my thanks to you Michael for being so observant and giving me the opportunity to express my thoughts and comments.
Stand by for the exploration, brought about by Michael's persistence, to now feature as a marketing point re sales of the flats and an insurance point re same.
ReplyDeleteWell done Cardy. So the goal posts are OK but will the spaces between move ? What about the prospective road structure ? Would this be akin to a horizontal soakaway and thus potentially compromise the integrity of the chalk behind the infills ?
Asking retired engineer.
"I should also point out that I can make life more difficult for you on the blogs than just deleting abusive comments."
ReplyDeleteI think clarification is required.
22.49 I get confused with anonymous commentators so I hope you will forgive the familiarity of my inventing a nickname for you, so Retired structural engineer and college lecturer, I hope you will find “College” appropriate.
ReplyDeleteSo College, welcome to the world to Thanet blogging.
You say that “between the column and the panels a foundation at this point could be superfluous.” Am I to take it that were the panels in question blockwork, then you would consider removing the virgin chalk next to the bottom of them to a depth of a about a meter could have undesirable results?
You say. This would lead one to conclude that the structure was formed as a single concrete reinforced unit and as such would act in a completely different manner to a concrete frame with blockwork infill panels.
Please appreciate that I am not a structural engineer, so could you explain in what way differently a blockwork panel would be expected to act?
Many thanks for the useful comment, as you can see from my errors over the pillar foundation, I am stumbling along in the dark a bit here.
Retired I think the roadway has to drain into the main sewage system, not a soakaway, due to the potential for oil and fuel contamination, the development roof drains into the inner harbour and the pipe for this has already been laid.
Not so sure about your other points, but am certain there are no on site soakaways, as I asked them why they were laying the drainage pipe between the development and the harbour.
What sort of clarification do you want 8.39, I am afraid it was just an abusive and personal comment aimed at a prominent local blogger.
Bluenote,
ReplyDeletePlease endeavour to read what I say with more caution before branding my remarks 'ridiculous'. I did not say that all adverse comments emanated from TDC. I suggested that some had done. What is it that leads you to believe that this was nothing more than an assumption on my part?
Your remark, "Some people just cannot let things go without a farewell snide dig" is curious. It is also gratuitous.
To anonymous at 20:19,
ReplyDeleteYou ask me, "How do you know that they are close to TDC if they're anonymous?"
This is something that I do not wish to discuss.
Though I might just be prepared to do if you you revealed yourself.
I can't see why it would be neccessary to lift the cloak of anonymity for you to explain comments which you made on a publicly accessible blog-site. I think it's very simple. You made the comments, you explain them, or the rest of us will have the nagging suspicion that you just made it up to make yourself look well-connected and knowledgeable.
ReplyDeleteTo anonymous at 14:10
ReplyDeleteWho exactly are your so called "rest of us" that have these nagging doubts. I was unaware that you spoke for such a broad constituency.
To anonymous at 14:10,
ReplyDeletePresumably, you are in your own words, "well-connected and knowledgeable". Otherwise you would not feel emboldened to speak for your "the rest of us".
College you are blooming genius mate, the Principle Condition report describes them as block infills and was written by Jacobs Baptie, who are civil engineers, so I rather took their word for it.
ReplyDeleteI don’t think the arches and the infill were cast at the same time, I think the Pillars, built my best guess is late 1920s, were slotted and the infill was cast as a curtain wall on steel fabric mesh, best guess in the late 1930s.
Historical research of this type isn’t easy and takes ages. I don’t know what the stability would be like with the chalk at the bottom cut away, any ideas?
Michael, what makes me think you have acquired another clever chappie on your blog who seems to feel he has the right to question others comments whilst failing to qualify his own.
ReplyDeleteTakes all sorts I guess.
Bill it’s a difficult issue and comment clarifies my thoughts on it, my hope is for a reasonably safe construction resulting in a reasonably safe development, with the ongoing cost to the public purse manageable. Easier for me to express this in post which I am putting up between other commitments this evening.
ReplyDeleteBluenote and Bill Richards, who I think must be joined at the hip, are generally unable to accept that there might just possibly be someone out there in the wide world who knows what they were talking about. College seems a genuine sort of chap and is certainly not completely buying into the "whole cliff is about to collapse" scenario. Every time a Tory apologist comes here and defends the indefensible it does make you wonder!!!
ReplyDeleteFor the record, Andrew, I am actually with College and feel his was a valuable contribution. It was John Holyer I was referring to in my previous comment.
ReplyDeleteAlso, for the record, never really feel the need to apologise for the Tories and fail to see how I am supposed to be doing that in my brief previous comment. For a One Nation Conservative you really do seem to have something of a vendetta with the Tory party. Wouldn't they let you join or something?
To Bill Richards at 11:11,
ReplyDeleteYou say, "It was John Holyer I was referring to in my previous comment."
Many thanks for the mention. May I say that your comments have been an immense contribution to the debate on this subject.
John, no offence intended. Enjoy your Easter weekend and I will try harder to contribute to the debate next time.
ReplyDelete