The work has begun – there may even be a TMR in it?
I have now started working for John Holland (following mandatory inductions) and have been given my first areas of responsibility. The marine Jetty project that I’m part of the project team for is basically constructed on 1200mm diameter Steel hollow piles that are all vertical. They are reinforced internally to transfer/resist all vertical loads as it is deemed better than installing raking piles due to the sensitivity of the area.
I have been put in charge of the test piles! This will delight John, knowing how much I enjoyed the foundations exercise, but it has potential for a TMR. This is because John Holland are using a new testing procedure (for JHG that is) with Osterberg Cells (O-Cells) to ensure that the piles will meet the axial (compression and tension) loads and pass lateral load tests. I will be researching this to death over the next few weeks with the test piles due for installation in May in order that we (the team) understand the methodology and meet the necessary specifications laid down in the Australian standards and Bechtel’s own scope.
I am thinking that seeing as I am already completing research into the O-Cells, why not compare it to the traditional static load testing and do a cost, safety, time analysis to see if on this particular project the selected method provides the best all round value. I can compare to the MOF project that is ongoing as they used traditional test methods using big weights and jacks. Thoughts and guidance welcomed on developing this concept further!
In addition I will also be responsible for the contract negotiation with subbies, sourcing the piles, manufacturing them as necessary (delivered in segments requiring on site welding), transporting them and installing them from a barge in the ocean. Then, obviously, the testing!
I am also going to be working on the temporary office facilities for the project and foundation design for the traveller. (This will become clearer in AER 1 where I will detail what this is – basically a moving platform that cantilevers out over the ocean to install the pile pairs. John may even have a drawing of one in his office?!?!)
So it’s now all go for me. Motivation is tough at 0415 when my alarm goes off but tends to pick up at about 0450 when I jump on the red rocket to whizz through the empty streets of Gladstone. The team are all friendly (I just don’t mention the ashes, RWC 2003 final, etc) and I’m steadily integrating with them and learning the lingo. There is a family BBQ on Sunday that we’re invited to, to celebrate a year on the GLNG contract, so a good opportunity to meet people socially and Lisa can meet the WAGs. There are quite a few ex-pats and Irish so she’ll be able to pick their brains if nothing else. The boys have settled into their kindergarten and nursery and even made some new friends (The family all had a play date today with one of Austyn’s Kindy mates). All-in-all, very happy, work is looking good and a free lunch thrown in on Sunday!
Roy
Holdfast Training Services Trial Blog 
Good to hear you’re actually doing some work
…Osterberg cells! I will have given you a slide of one in one of my foundation lectures. I’d have woken you up had I known…..
Look-e-here…
What they are used for is to embed in the pile- usually at the toe; so they allow the load test to asses the toe load registered for a given applied at the head. A vertical load will be applied presumably by using piles either side as a tension frame. The ‘O’ cell will monitor how much of the head load the toe actually ‘sees’.
The difference (and I really do feel bad about leaving you sleep now) is the skin friction element.
Feeling ever-worse , you would be aware that the ‘O’-cell at the toe should register surprisingly little load for low strain and this will increase as the head strain approaches the (theoretical) failure load for the pile (;That being the load that generates a head movement roughly equally to 10% of the pile diameter
A decent TMR might be the performance of the piles .v. the theoretical capacity
Or, if the piles are being designed as vertical piles taking lateral (berthing or wave) actions, how the lateral capacity is assessed.
John, the berthing piles are vertical, 1500mm diameter so could be looked at. I’ll do more investigation today. Roy
John,
The vertical load will be loaded using the O-cell as well by moving it up and down within the pile and by the use of a RC Socket. I’ll send the presentation i’ve been given on it to you so you understand what i’m getting at. There is no option to load the piles vertically from out at sea as the barges/pontoons won’t work at a depth of 35-45m for stability reasons and the chance of loading a balanced load of dead weight to failure is not an option for H&S reasons! The mooring dolphins and berthing dolphins are the main focus for lateral testing and very simply, a hydraulic ram or jack are going to be placed between 2 of them and see how much displacement there is at various %’s of the design load up to either 200% or failure, whichever comes first!
Regards,
Roy
Oh…that pile on the link is more like a twig or something…I’ll get hold of some big manly pile shots for you where the diameter is as big as a man and you don’t need a confined spaces permit to go inside!