11-30-2009, 01:46 AM
The particular pilings specified could stand the load, although they are as you cited probably only rated for driving in sediment soils and another issue with driving in solid lava would be fracturing. In all reality there’s really no true valid reason to drive a pile for a house on solid lava. The expenses alone would be cost prohibitive for such a venture not to mention the gamble engineering wise… imagine driving a steel pile into the lava only to see it disappear down the hole when it hits a lava tube 20’ down (lol he he he, bye-bye).
It sounds as if you intend to build a full blown out structure/house. If you’re considering fiberglass for it’s resistances to moisture, insects etc… there are other alternatives that are far less expensive, concrete columns being one of them. Concrete columns for light loads such as residential homes do not easily succumb to seismic activity like heavy loaded municipal type concrete columns. If your concerns regarding concrete are seismic related then have them toss a mesh binder in the mix such as chopped fiber glass. The fibers will greatly impede any possible load fracturing that might remotely occur during a seismic event when combined with the steel rebar. You can also spec wire mesh just inside the perimeter surface of the concrete column to alleviate such concerns. Personally, I would never be concerned about a common concrete column with standard structural mix and common bar alone for a house.
Before you pour a concrete column on solid lava you will have to drill holes in the lava and use epoxy to adhere the rebar in the holes, these will act as pins ensuring that no slipping will occur at the foot joint effectively joining the concrete to the lava rock permanently. There are some pretty nifty concrete form systems available today and one is much cheaper than the common paper based Sono tube for round column forms. I’ve no clue as to your terrain conditions but you might be able to use the green building based Fast-Tubes for concrete column forms. For more info on this product you can contact Richard Fearn from Fab-Form and look through their website at http://www.fab-form.com/products/fasttube/fasttube.html
If you're building in/on Lava you've already got one of the best soils with regard to being structural friendly, there's no need to make things difficult or pointless.
BTW just to point out an errant term widely used in Hawaii - post and pier is a very poorly coined term and in all reality is nothing but jibberish even when one is using a concrete footing with a post atop it. It's properly cited as footing block post and beam. It's pier and beam if using a pinned concrete column or pinned steel columns with no specified footing. Piers are strictly members that are verticle and serve as a footing in direct contact with soils and then directly support a horizontal member.
Hope that helps.
E ho'a'o no i pau kuhihewa.
It sounds as if you intend to build a full blown out structure/house. If you’re considering fiberglass for it’s resistances to moisture, insects etc… there are other alternatives that are far less expensive, concrete columns being one of them. Concrete columns for light loads such as residential homes do not easily succumb to seismic activity like heavy loaded municipal type concrete columns. If your concerns regarding concrete are seismic related then have them toss a mesh binder in the mix such as chopped fiber glass. The fibers will greatly impede any possible load fracturing that might remotely occur during a seismic event when combined with the steel rebar. You can also spec wire mesh just inside the perimeter surface of the concrete column to alleviate such concerns. Personally, I would never be concerned about a common concrete column with standard structural mix and common bar alone for a house.
Before you pour a concrete column on solid lava you will have to drill holes in the lava and use epoxy to adhere the rebar in the holes, these will act as pins ensuring that no slipping will occur at the foot joint effectively joining the concrete to the lava rock permanently. There are some pretty nifty concrete form systems available today and one is much cheaper than the common paper based Sono tube for round column forms. I’ve no clue as to your terrain conditions but you might be able to use the green building based Fast-Tubes for concrete column forms. For more info on this product you can contact Richard Fearn from Fab-Form and look through their website at http://www.fab-form.com/products/fasttube/fasttube.html
If you're building in/on Lava you've already got one of the best soils with regard to being structural friendly, there's no need to make things difficult or pointless.
BTW just to point out an errant term widely used in Hawaii - post and pier is a very poorly coined term and in all reality is nothing but jibberish even when one is using a concrete footing with a post atop it. It's properly cited as footing block post and beam. It's pier and beam if using a pinned concrete column or pinned steel columns with no specified footing. Piers are strictly members that are verticle and serve as a footing in direct contact with soils and then directly support a horizontal member.
Hope that helps.
E ho'a'o no i pau kuhihewa.