huangyhg

constructing columns in water
does anyone have any resources on construction in water. (lake or pond.) i am working on a project that the civil wants to use auger cast piles. i've always used driven timber piles. this part of the project is a fishing pier in a state park.
any suggestions on construction material, suggestion method for the contractor, and/or shoreline disturbance requirements?
thanks.
why not use driven concrete piles?
how would you connect to an augercast pile under water? would you use divers?
i would say, use a driven pile also. though i am curious about the connectin detail.
or concrete filled steel tubes piles?
you will have to use a coffer dam. very typical in bridge engineering
if the civil / architect wants to see an exposed concrete pile above the waterline, then use a driven 8" diameter steel pipe pile as a form. auger out the material in the pipe pile. fill the pipe pile with the appropriate reinforcing and pour the pile to the height desired above the waterline. once the concrete has cured, cut off the pipe pile form at the mudline with an underwater torch. should be able to cast in place any attachment required at the top of the pile for the pier.
only problem here i see is whether the local building department/corps of engineers/epa will allow you to place piling at that location (eelgrass, etc.). might turn out to be an environmental problem, not an engineering one.
mike mccann
mccann engineering
msquared48,
my question to you, after cut off of the pile at mudline, how will it be possible to strip the steel pipe pile without breaking the concrete inside?
cut all around the ontside of the pile at the mudline, then make two vertical cutes to the top of the pile, 180 degrees apart. should come off at that point. may even be able to pry it open and lift it off with only one vertical cut. had to do this 25 years ago when a section of 8" diameter pile got stuck to the head of a piledriver. smaller problem then, but same basic idea now. should work.
mike mccann
mccann engineering
msquared48,
i think the idea is okay for just one pile, but extremely costly for a project that will require more than one pile. also, the heat during torching may affect the quality of the concrete.
hey...this is a government job. who worries about cost when the government pays $500.00 for a screwdriver? obviously not the gao! or was that $5000.00?
seriously though, i would not be worried about heating up the concrete too much with all the water in the vicinity. how many pile are involved, and how far do they project above the mudline on average?
mike mccann
mccann engineering
cofferdam too expensive.
i doubt the cutting off the steel pipe is a very good idea. i also doubt there is any such thing as an underwater torch - i think the only option is arc-air gouging.
why not leave the pipe in place, if you really have to remove then you should make it up into a bolt together formwork in the first place.
i would go for driven timber, steel or concrete piles. if the auger is a must then a steel casing (or formwork as mentioned above)could be pushed in and then auger through the void.
during concrete i would expect bentonite to be used, if not i can only imagine what sort of condition the concrete will be in.

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]