Releasing of temporary bracing to marine piles
Releasing of temporary bracing to marine piles
(OP)
In a project, it is specficed that all 1200mm dia marine steel tubular piles in 18m deep of water had to be temporary braced and can only be released before installation of the steel roadway frames. All the steel piles are directly socketed into rock and grouted with 40 MPa concrete. There is no other overburden.
The contractor wanted to release the temporary brace to the piles after 3 days when the concrete grout achives 25 MPa.
What do the designer has to check for if the contractor wanted to release the brace at earlier date? Base on the environment loads and strength of the piles, there is no problem as the 1 in 20 years ARI loads are significantly less than 1 in 100 years condition.
The contractor wanted to release the temporary brace to the piles after 3 days when the concrete grout achives 25 MPa.
What do the designer has to check for if the contractor wanted to release the brace at earlier date? Base on the environment loads and strength of the piles, there is no problem as the 1 in 20 years ARI loads are significantly less than 1 in 100 years condition.





RE: Releasing of temporary bracing to marine piles
RE: Releasing of temporary bracing to marine piles
But if the temp brace is allowed to be release early, what will be the consequences and why in the first place the specs call for bracing?
What are the design to be checked if allow early release?
RE: Releasing of temporary bracing to marine piles
RE: Releasing of temporary bracing to marine piles
The pile can be unbraced is equivalent to being capable of taking full loaded after it has achieved its full strength. Otherwise could the grout be damaged under unbraced condition?
A truss frame is sitting on top of the piles and it can be acceptable if the brace can be released just prior to the installation of the truss which is a pernament brace.
So could the grout (actually is concrete as the annular between the pile OD and the socket is about 75mm (3 inches) be damaged if it is not properly set under 28 days?
RE: Releasing of temporary bracing to marine piles
RE: Releasing of temporary bracing to marine piles
RE: Releasing of temporary bracing to marine piles
RE: Releasing of temporary bracing to marine piles
It is problem with early loads on young concrete instead of loadings at 28 days? I wonder where can I get infomation on this subject?
RE: Releasing of temporary bracing to marine piles
That's why it is called heavy construction.
RE: Releasing of temporary bracing to marine piles
RE: Releasing of temporary bracing to marine piles
If the piles are 'just standing there,' then 3 days sounds sufficient,
depending somewhat on the grout mix design.
Do you know the curing (strength gain) characteristics?
For example, if the grout has a retarder (doubt it), then more time might be required.
Ask the QA/QC lab for early breaks to verify the grout strength.
RE: Releasing of temporary bracing to marine piles