Type of Foundation and Method of Installation into Boulder &Gravel

[fabianjm]

Dear all, Do you have any experiences about the type of foundation or method of installation into Boulder & Gravel layered soil (covered about 10m) without using heavy equipment(high cost).

 

[hokie66]

How big are the boulders/cobbles/gravel? Is this naturally occurring river sediment? If so, spread footings would be my choice unless the loads are very large.

 

[fabianjm]

Thanks hokie, This is real case in some part of my provinces has a geology problem which the boulders and gravel around 5cm to 1m covered about 10m. Mostly the bridges foundation were failed because of limitation of heavy equipments(high cost) and the length of bridge about 25m to 200m. The main problem is limitation of budged.

 

[hokie66]

My advice was based on footings for buildings, not bridge abutments. Stream scour would certainly be a problem in that type of material. How did the bridges fail?

 

[fabianjm]

Thanks hokie, yes some of the bridges foundation were damaged because its couldn't installed the foundation (driven pile,bored pile or caisson) into the design depth because of the limitation of heavy equipments and the river was given heavy scouring

 

[dicksewerrat]

Does it cost more to bring in the right equipment or rebuild the failed bridge 3 or 4 times?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[hokie66]

Without heavy equipment, you could resort to the old way of advancing a caisson within a tube. Do all the digging by hand within perhaps precast pipe sections used as the tube. That wouldn't work so well if ground water occurs within your depth. Maybe you can't build a decent bridge without increasing your budged (sic).

 

[fabianjm]

Thanks dick this the problem in the development country sometimes difficult to understand their behaviour.
Thanks hokie digging will need a lot of time

 

[hokie66]

fabianjm,
I take it you are not from the developing country, but doing work there. It is surprising how quickly some of these countries can accomplish manual tasks. They tend to have plenty of labor, if unskilled.

 

[Bluefoot]

The linked paper here may be of some use though it is not for the situation there.

A somewhat properly designed and constructed foundation has to be in place to avoid the failures.

 

[fabianjm]

Thanks in advanced Bluefoot for your references paper and thanks also hokie for your recommend