STRUCTURAL ENGINEER'S REPORT ON THE SEA DEFENCES - AUGUST 2006

The piles bottomed out at the required level and could not be pushed further. A vibratory hammer was used with great success. The vibration was minimal and there was no damage to the Chapel. The piling hammer was carried on a machine provided by UBC. The whole rig sat on a temporary platform of rock and gravel on the beach to get good height and tidal reach.The piles and equipment arrived on Monday but a hitch in the hydraulics prevented a start then.I instructed a spare pile to be installed first to retain some lightweight propping to the corner of the building. This pile went down with ease and a couple of acrow props were then kicked off the face of it. The rest of the piling then followed on.There was a little vibration as the piles broke through the gravel surface crust this having been compacted over the years by foot traffic and water. The different layers of subsoil could be correlated with the behaviour of the pile and hammer and tied in with the SI done a few years ago.

The ground at the corner of the building is very soft compared to further along as found in the SI. The piles are well anchored below the soft soil however and able to prevent a slide as per the design approach.I have not excluded the possibility of further work locally at the corner depending on the results of ongoing monitoring of the tell-tails. The presence of the piles will simplify any underpinning processes required.I have instructed a layer of geotextile to be placed on the ground between the piles and the chapel, and then to carefully place a layer of rock and gravel over the top of it. This will protect the base of the walls pending the Architects decision on how to improve the path. The rock is temporary. A large tide is due in October. A step or ramp can then be made  Public safety needs to be provided for