This is a report by a professional firm of civil engineers commissioned by Thanet District Council.
I don’t know how much I had to do with this report being commissioned, I had been asking the council about the advisability of building so close to what appeared to be a tall and rather dangerous cliff for some time, before it was commissioned.
I had a fairly long discussion about this with a friend of mine recently and realised that I hadn’t made the significance of this report clear enough.
Bright enough chap but no engineer, what he had assumed was that the concrete cliff façade was built to hold the cliff up and stop it from collapsing. His logic ran along the lines of:
It’s made out of concrete; concrete is strong; therefore if properly maintained it will stop the cliff from falling down and demolishing the new development.
Obviously he had completely misunderstood the cliff façade, this is a concrete wall about 20 metres tall and averagely about a quarter of a metre thick in old money this equates to something over 60 feet tall about as thick as a 2 brick garden wall and about 300 yards long.
Any engineer looking at this will tell you that without the cliff face to hold it up a puff of wind would blow it over, it has one sole purpose which is to prevent the chalk from weathering, something that causes bits of chalk to drop off.
The biggest of the repairs to the façade can be explained in layman’s terms thus; a big bit had come lose from the rest of it and moved out away from the cliff a bit, so they screwed it to the chalk behind to stop it falling down.
Having got that out of my system here are a few quotes from the report and notes on their significance.
“Marina Esplanade Façade is in a condition that would be defined as short serviceable life.”
I take this to mean that the façade won’t last as long as the new building.
“Evidence of particle migration at the top surface also gives rise to concerns that hydrostatic may be imposing on the structure forces, which the concrete barrier is not designed to resist.”
I take this to mean that an unknown amount of chalk has slipped down and is lose behind the barrier pressing against it.
“It is considered that erection of a tower crane for construction purposes should be erected at lest 22 metres away from the edge of the façade topside.”
I take this to mean, the whole thing is riddled with tunnels and cracked chalk, so since we just don’t know how strong it is treat it as a lose pile with its sides sloping at 45 degrees. As the cliff is 22 metres high don’t put anything heavy closer than 22 metres from the edge the edge.
“the wall is thinner than the designed thickness”
I take this to mean that when constructed the contractor didn’t follow the plans.
Lets assume for a moment that the repairs had worked out as was hoped, even then we would have had a cliff riddled with tunnels and caves, some of which have been discovered and others which if they are there haven’t been discovered. This cliff has sustained considerable damage because of lack of maintenance to the surface above, so the chalk has many cracks in it.
I should point out here very clearly that nothing has been done to strengthen the cliff itself apart from a small amount of filling of some open holes on the front of the façade.
The pictures in the post were taken by me this morning, sorry I only had my ancient pocket camera with me, it’s more kilo pixels than mega but it gives you some idea.
You can see things are not as they should be.
I am afraid the brown streaks in the picture above may mean the reinforcing rods are still rusting.
As you can see from the picture above the nice new coating comes down not to a solid foundation but muddy chalky soil.