My recent posts about this development has meant that I have had various dialogues with several engineers that specialise in various aspects of chalk and problems related to different projects involving its stability.
One aspect of the report on the condition of the cliff façade that has generated particular interest is how the bit of it that was on the move had been dealt with, the following is a quote from the report.
“There is an area of the façade, which is severely cracked and has experienced outward displacement. This indicates that load resistance failure and requires a serious engineering solution possibly ground anchors. The drawings indicate that the façade was to be constructed to a minimum thickness of 310 mm, however inspection through the weepholes, show varying dimensions down to 230 mm.”
Obviously with the total lack of public consultation about this major project there is scant information about how this problem was addressed, or how successful the work done to this part of the cliff was.
I did take some pictures click on them to enlarge and there is this quote from Dave Green’s Eastcliff Matters blog:
“The area of cliff facade which has not yet received the specified anti-carbonation coating is awaiting stabilisation works which are currently being designed. Testing undertaken during the construction phase indicated that a section of cliff facade in this location is not sufficiently stable. The solution to this will involve the installation of a series of ground anchors which will tie the concrete facade to solid chalk several metres behind the face of the facade. A new reinforced concrete 'badge' will be cast over the existing facade in this location to allow the new anchors to be tensioned sufficiently to stabilise the existing structure. Once complete, the works will receive the same coloured coating as the rest of the facade to protect it from future chloride and carbonation attack. The design has taken longer than anticipated, and work was hoped to commence onsite in October. However, our consultant has been slightly delayed by the company who produced the geotechnical information but has now completed the design work and will produce contract drawings/documentation next week for pricing. I think we should now be in a position to return to site and commence these additional works at the beginning of December.”
For the non technical reading this it easiest to liken it to screwing the concrete wall in front of the chalk cliff to the chalk behind, to stop it from collapsing.
What really riles me though is the arrogance of the people involved in assuming that local people wouldn’t be interested in such a major civil engineering project, so they didn’t tell us what was going on, just as they haven’t told us why a lot more of the promenade has now been boarded off in the last week.