Existing Building on Piles?

[peru4444]

I have recently started on a project involving the refurbishment of an existing building. We have carried out some localised trial pitting to determine the existing foundations. One of the column bases appears to irregularly shaped (approximately hexagonal) - is this a likely indicator that the existing building is on piles? Or could it be a hexagonal mass concrete bearing pad? Is there a way of determining this for certain? It isn't yet possible to excavate down to formation level of the bases due to lack of equipment on site

 

[hokie66]

How big is the footing? Where I have practiced, in the US and Australia, hexagonal footings would be very unusual, whether on piles or not. Are you in Peru as your handle indicates? If so, asking engineers or building officials in the area might shed some light on what you have observed.

 

[peru4444]

The footing is quite large - approximately 3.5 m maximum width.

I actually practice in the UK, though I am originally from Lima. I have spoken to a UK engineer in the office also but he is unsure and hadn't encountered this previously.

 

[PUEngineer]

Although a US document, the CRSI (concrete reinforcing steel institute) Handbook shows an option for an octagonal cap in some of the larger pile groups. Basically it's a rectangular cap with the corners clipped. So, it's not a regular octagon but still an octagon as it has 8 sides.

 

[hokie66]

Now that I think about it, it is common practice to detail pile caps for 3-pile groups with 6 sides. Not equal sides, but a type of hexagon. For 3500 width, they would probably be quite large bored piles. Still only speculation...

 

[BAretired]

In other words, nobody knows what kind of foundation exists. Do not assume anything or you could find yourself in trouble.

BA