Pleasurama cliff façade report.

I have been in communication with Cardy Construction and Thanet district Council about the condition of the cliff façade. My take being that whatever happens over the Pleasurama issue the doubts of the cliff there have to be resolved.

It is my intention to report both the cliff façade and the sea defence as safety issues and below is a first draft, of the cliff façade part of this report, any help improving this would be appreciated.

In the first instance plans for The Royal Sands development were submitted and approved without investigating the civil engineering problems peculiar to the site.

About half of the planning sheets relating to the development are on http://www.ukplanning.com/thanet Application No:            F/TH/03/1200, it should be noted here that pages on this site do not retain the same web address so it isn’t possible to bookmark them or send links to them by email.

The plans were changed on several occasions due to concerns about the height of the development, the issue being that the height of the development, for which plans had been approved, was greater than the distance between the baseline of the building (the existing promenade) and the height of the cliff (public footpath gardens and bandstand in the cliff top).

This is mostly relevant here because the reduction in height was partly achieved by lowering the ground floor ceiling of the proposed development, this meant the two-way access road through the development (residents cars and HGVs delivering to the hotel and retail units and removing refuse) was moved into the 4 metre gap between the back of the development and the cliff façade. There are potential problems here with lorries trying to manoeuvre past other vehicles catching the cliff façade support columns and the columns supporting the building.

After the planning consent was approved the intention was to build the development using the driven pile method of construction, as the concrete cliff façade appeared to be in poor condition (visible cracks with vegetation growing out of them) I raised concerns with the council about its condition.  

In 2005 the cliff façade was inspected, see http://thanetonline.com/cliff/id2.htm this inspection was a visual inspection of the exposed parts of the façade and didn’t include any investigation of the façade foundations or the brick part of the façade at the north-eastern end of the site which was constructed in 1860.

Please note 6.34 Conclusion “Marina Esplanade façade is in a condition that would be defined as of short serviceable life.”

Work on the façade maintenance regime occurred during 2009 this mostly consisted of filling the cracks, coating the façade and resurfacing the cliff top footpath above the façade to mitigate surface water ingress behind the façade. There was also extra work using soil nails to increase the structural integrity of the area where the upper barrier had moved horizontally, see http://thanetonline.com/cliff/id4.htm Appendix D.

Scaffolding was erected for the work and this involved some levelling of the ground adjacent to the cliff façade it was at this point that I first noticed that aspects of the cliff façade foundations seemed inconsistent with the rather limited foundation designs published in the reports.

I can send you copies of the emails about this between me and Jacobs if you require confirmation of this. 

After the façade maintenance work was finished at the end of 2009 I was concerned that part of the façade appeared to be bulging and that there should be some sort of inspection of the façade foundations so I contacted the council.

At the end of 2009 beginning of 2010 the council arranged for the bulging part of the façade to be hacked out and rebuilt, but didn’t appear to address the issues relating to the façade foundations.

Around this time the developer SFP appointed the third main contractor as the main construction firm for the new development, Cardy Construction.

I discussed the issues relating to the cliff faced with their MD ***** ***** on several occasions both by email and by telephone. I think a fair summery of the various communications is that he wasn’t happy about the façade foundations, the overall condition of the façade or the quality of the work on the repair to the bulging part.

Early in 2010 Cardy Construction made a limited investigation of the south-western, portal part of the façade, see http://thanetonline.com/cliff/index.htm most of this façade consists of a line of square cross section concrete pillars, forming oblong portals, cast against the inclined chalk cliff face. Above these is a solid concrete cliff wall, or apron, cast onto the chalk cliff face which has had dovetail horizontal grooves cut into the chalk to it to give additional support to the apron.

My understanding is that the upper, apron part of the façade was built first and originally sat on top of the bare chalk cliff which stepped out at the level of the bottom of the apron, the portals being erected at different times as the chalk beneath the apron deteriorated.

The largest and most substantial looking of the pillars is in the form of a buttress which 2010 Cardy Construction’s investigation says has inadequate foundations and the short term remedial underpinning they recommended in 2010 has never occurred.

It also begs the question: if one pillar foundation in the portal part of the façade was investigated and found to be inadequate, why weren’t the other foundations there investigated?

During 2011 more cracks, another bulge and significant amounts of vegetation appeared on the façade and once again I contacted the council and asked them to inspect the façade.

This inspection occurred in 2011 or very early in 2012 as the draft report was dated 2/3/2012, see http://thanetonline.com/cliff/id14.htm firstly I should point out that the remedial work recommended then hasn’t occurred.

The most concerning aspect of this inspection report concerning the façade foundations are 6.1 which says that the foundations and subsoil was exposed by the construction work which occurred in 2010.

I should point out here that the pillars of the portal section are not supported by the chalk cliff being stepped, as they are in the arched section. This means that the entire load of the concrete pillar plus any additional load from supporting the apron appears to be sitting chalk subsoil which has been exposed now for around four years and will have been subject to weathering.

Such design drawings as are available show concrete load spreading pads in the form of an inverted T however in many cases the profile of the façade pillar continues below the concrete in chalk. It wouldn’t seem possible that an inverted T could have been dug in the chalk and the concrete poured into it, so it would seem unlikely that there is any load spreading provision for these concrete pillars.  

Either the profile of the pillar has been dug down below the exposed level and what is visible is the chalk adhering to the concrete, or the concrete pillar is sitting an exposed chalk pillar. This is a problem that needs investigation.

The other part of the cliff façade needing serious investigation is the 1860 brick structure at the north-eastern end of the site. The rest of this structure, steps and tunnel portal collapsed with no warning in the 1960s, the cliff was surveyed and during the rebuild there was a further large chalk fall there which demolished much of the reconstruction work.

It isn’t possible to see the foundations of the two large brick pillars as they have not been exposed during construction work. The foundations of the brick buttress wall between them has been and still is exposed and isn’t sitting on solid chalk but on some sort of made ground which appears to contain a proportion of topsoil, chalk pieces and brick rubble.    

From the point of view of the development restarting to the approved planning application F/TH/03/1200 the significant issues are:

Is the cliff façade safe enough for work to commence on the development and if not what are the costs involved in making it so?

What is the expected life of the cliff façade?

Is it possible to adequately and economically maintain the cliff façade in the 3 metre gap between the cliff façade and the development?  

The big question though is will there be proper economic and civil engineering provisions made to ensure the cliff façade is and remains safe for people to live under it for the life of the development?

My own opinion is that trying to patch up a cliff façade “of short serviceable life” is unlikely to be the best solution both economically and in terms of public safety.

Royal Sands Development Ramsgate, Pleasurama Cliff, is it Safe?

Once again this development has problems, a minor symptom here is that small bits of the cliff façade have been falling onto the site from above for some time.

You can see the problem in the picture above, click on it to enlarge and then click on it to enlarge some more.

This is a close up of the problem, this is not such a worrying problem – the bits falling off that is – as you may think, cliff safety to an extent is governed by the laws of chance, there really isn’t another economic way of dealing with the problem.

We overcome this problem by having signs saying don’t sit under the cliff. Lets say for example we have a bit cliff where bits fall off about four times a year, there are 525600 minutes in a year, let us also say that the danger posed from a fall lasts for 15 seconds so that in the course of a year there is a minute where you could get hurt being under this bit of cliff.

You can see that the danger of getting hurt is relative to the time you spend under the bit of cliff, walk under it occasionally and the chances of being hurt are thousands to one. Sit under the cliff every day during the summer and you start to get to something like a 1 in 4 chance of being hit by a bit of falling cliff.

Build your house under the cliff, or start on a 4 year contract to work under the cliff and you can see that a serious problem emerges.

With the Pleasurama site we have a situation where parts of the cliff wall have visible problems and parts periodically drop off, in fact a classic do not sit under the cliff situation.

The bit in the pictures above with the masonry falling off is part of the old railway tunnel entrance, bridge and steps, built in the 1840s.

The picture above shows the fire brigade digging through the rubble looking people buried when part of this 1840s structure collapsed in 1967.

There are several factors that cause large collapses, one being building cliff walls as they hold back smaller falls until there is sufficient weight of chalk to cause the wall to fail.

Another factor is surfacing the top of the cliff, as when the surface cracks the rainwater is concentrated in one place, the crack, causing localised damage to the chalk below.
The main cause of cliff falls though is poor drainage of the surface above the cliff.

You can just see the edge of the cast iron drain grill in the bottom right hand corner of the picture above, the drain in question is completely full of earth and I had to push some of the weeds growing in it, out of the way to expose the grill for the photograph.

This is the same drain viewed from further away, unfortunately it is at the edge of the top of the cliff above the 1840s part of the cliff wall, in the photographs above.

The other bit of the cliff wall, that has problems that are visible, is at the other end of the Pleasurama site

You can see from the picture above that the bit of the cliff wall in the middle at least looks like a reasonable piece of civil engineering, it is a series of arches with an infill. It all slopes towards the cliff by the same amount, hasn’t got many cracks in it or weed growing out of it.

You can also see from the picture above that the other bit of the cliff wall, the bit I am concerned about that runs between the middle of the site and the lift is a bit of a mess.

It doesn’t have the look of being designed and is all different angles and shapes, jerry built is the term that comes to mind.

The picture above was taken this time last year and was one of a series that I sent the council then and that I believe was instrumental in getting the repairs to the repairs done.

The right hand of the two block panels in the picture above is the one that the council had replaced after they had sent about £1m on having most of the cliff wall repaired. This picture was taken before the repair to the repair and you can clearly see the vertical crack that was filled, painted and then opened up again.

The picture above shows the council’s contractor replacing the panel. The other thing that the council had done at this time was to remove the weeds. This is important as their roots damage the cliff wall even more.

The picture above shows the same two panels now, as you can see the weed growth on the left hand panel is appreciably worse, considering that all of the weeds were removed at the end of last year, around the time the panel on the right was replaced and I would say that the condition of this part of the cliff needs assessing.

The right hand panel is the new one and serves as a control in this instance.

Now we have a situation where work has started on the site and people are regularly working beneath the cliff wall.

I was, as some of you will know an engineer before I became a shop assistant and over the years I worked in engineering it was constantly drummed into me that safety was paramount.

I was also told that safety was everyone’s responsibility and so I felt obliged to report the situation on this site to the Health and Safety Executive.

On Monday I telephoned the HSE and asked them to go and have a look at the situation there as I thought aspects of it were potentially dangerous.

On Wednesday they phoned me up and told me that they had telephoned the council and Cardy Construction whose workers are on site and had been assured by both of them that the cliff was safe.

I am afraid at this point I became rather annoyed and I discussed the matter further with them.

I am also afraid that they assume that I am some sort of nutcase, who knows they may be right.

My point here though is that if someone reports something they consider may be dangerous to the HSE and asks them to go and investigate it, then instead telephoning the organisations reported as having something potentially dangerous and asking them if they thought it was dangerous, they perhaps ought to have considered some sort of alternative action.

There is always the possibility that possibility that the person phoning them wasn’t a nutcase.

Anyway after further discussion the HSE told me that Cardy Construction had also voiced concerns about the stability of the cliff with the council and that the council had assured them that there was nothing wrong with the cliff or the cliff wall.

Now either there is nothing wrong with the cliff wall or there isn’t, if there is there is a good chance that part of it will collapse once again, if there isn’t then it won’t.

There is a problem here though and that is the council’s consulting engineers, that is the engineers who do their cliff inspections, are the same engineers who supervised the £1m cliff wall repair, that is the repair that has already been repaired.

Over the years I have produced many blog posts and internet pages about the Pleasurama site and clicking on the links below should get you to them, for those of you in a hurry, but wanting to know more about what happened last year when I had a close look at the site and found the problems with the cliff wall, here is the link to that post http://thanetonline.blogspot.com/2009/11/royal-sands-development-how-dangerous.html