Holdfast Training Services Trial Blog

This week on site the steel fixers have been getting the reinforcement bar ready for the big pour this weekend. So it was hands to the pumps for a 630am start on saturday. Not to happy but a good opportunity to expand my knowledge and collection of concrete photos that only engineering pests would appreciate…Rich I will send you some copies.

                        The arrival of the diamond core drilling subcontractor on Friday, who I shall call Heath & Robinson caused me a little brain ache and just reminded me of my role and its not to with the guys wielding petrol saws.  The issue, during the pouring of the concrete piles that form the shaft perimeter, steel tubes were cast into the pile to allow sonic testers to be lowered into the centre of the pile to test the integrity of the pile and then for inclinometers to be emplaced to monitor ground movement. During the pouring the tubes connections failed and the concrete blocked the tubes so now neither sonic testing or inclinometers may be lowered into the piles. The decision was taken to diamond core the piles to clear the blockage and having had nothing to do with the entire planning of this operation I was suddenly handed a hospital pass yesterday to approve the method statement by this morning. The method statement was sound part from one small detail which was their improvised clutch. The purpose of the clutch is to clamp the diamond cores whilst they further cores are added or removed from the drilling rig.

he proposal was to use a couple of bits of wood and threaded bar to clamp the cores, all seemed fine until I performed a “fag packet calc” (Moran 2013) to determine the vertical load that the improvised clutch had to resist being in the region of 1.5T. Cue the alarm bells!!! Not convinced that two bits of 2”x4” could resist this I decided to panic the men early in order to stall for time and to try and determine if my theory was right. Being the only person in the office who had any idea that timber calcs had many K factors that needed to be considered and that the vertical force we could potentially be facing would have to be resisted by a horizontal force that would need to generate sufficient friction to prevent the diamond cores descending to middle earth, from which I think even Bilbo and his band of merry midgets would have difficulty in retreating them. Quick phone call to Richard in the rear guard to confirm my theory and to gain further guidance and I am now set to carry out the “fag packet calcs” (to follow for those interested.) This whole episode goes to prove another of the great orator’s theories that “you should never assume anyone knows more then you” as they quite clearly don’t. To be continued…