LATERAL CONCRETE PRESSURES ON FOUNDATIONS 2

[steven007]

IF I HAD A 2METRE DEEP X 450 WIDE OPEN TRENCH FILL FOUNDATION AND I POURED GEN 1 CONCRETE INTO IT, HOW MUCH LATERAL PRESSURE WOULD BE FORCED UPON THE SIDES OF THE EXCAVATION?

THANK YOU GENTLEMEN

 

[hokie66]

I am not familiar with the term "GEN 1", but if it is normal weight concrete, 2400 kg/m^3, you can use a linear pressure assumption. The pressure at the bottom would thus be 48 kPa. It actually depends on the rate of placement.

 

[steven007]

Thanks hokie66,

Gen 1 is a British standard of concrete basically mass concrete. I understand linear pressure assumption, but is concrete truely a fluid? Does all the aggregate act laterally at the bottom of the trench as if it is a total fluid? Has there been any research into this, say for use in formwork side forms etc?

I would expect some losses caused by friction in the concrete mix and due to the small width of trench?

Any thoughts?

Many thanks.

 

[msquared48]

The forces on the concrete wall would be the same seen by concrete forms, walers, etc., and there are many design manuals out there for concrete form design. I have one somewhere and will try to find it.

Mike McCann
MMC Engineering

 

[msquared48]

Found it - "Formwork for Concrete" by M. K. Huro, fourth edition, an ACI publication. My edition was published in 1981. The fifth chapter deals with pressures, that vary with rate of placement and temperature. I will scan and post a table listing some pressures to consider.

Mike McCann
MMC Engineering

 

[msquared48]

Here is the table:

Mike McCann
MMC Engineering