Soil Pressure - U.S. to Metric Coversion Question
Soil Pressure - U.S. to Metric Coversion Question
(OP)
Hello, I hope I have found the right forum.
I have a project that requires addition of metric values to a set of standards now shown in U.S. only (they will now show dual units).
I am not an engineer, but have construction and technical background.
I am somewhat confused as to the proper conversion (standard useage) for the U.S. designation of Pounds Per Squre Foot(PSF)to metric.
Is the normal conversion factor:
square meter (kg/sq m)
{note I could not show supersubscript 2 to define "squared)
Or would Pascal be appropriate? (I am not certain if Pascal is a square/unit measurement or just pressure).
If Pascal is a square/unit measurement, would either of the two be appropriate?
I hope I laid this out so it is not confusing.
I have a project that requires addition of metric values to a set of standards now shown in U.S. only (they will now show dual units).
I am not an engineer, but have construction and technical background.
I am somewhat confused as to the proper conversion (standard useage) for the U.S. designation of Pounds Per Squre Foot(PSF)to metric.
Is the normal conversion factor:
square meter (kg/sq m)
{note I could not show supersubscript 2 to define "squared)
Or would Pascal be appropriate? (I am not certain if Pascal is a square/unit measurement or just pressure).
If Pascal is a square/unit measurement, would either of the two be appropriate?
I hope I laid this out so it is not confusing.





RE: Soil Pressure - U.S. to Metric Coversion Question
Pascal is NOT the right measure for soil pressure, since 1 Pascal is such a low pressure. You can think of it as the weight of 1 'standard' apple (the Newton being the unit of force)on every square metre.
The usual geotechnical pressure unit is kilopascal. The rate of conversion is 1 kPa = 20.885 lbs/sq.ft.
RE: Soil Pressure - U.S. to Metric Coversion Question
Right, kilopascals it is, I should have been clearer on that point.
I just wanted to make sure the conversion factor was acceptable.
i.e 2700 psf = 129.28 KPa.
Thanks so much!!
RE: Soil Pressure - U.S. to Metric Coversion Question
RE: Soil Pressure - U.S. to Metric Coversion Question
N/mm2 (= kPa)
kg/cm2
ton/cm2
etc. Then there is the "force" vs the "mass" pressures. Generally, all these differ by some factor of 10 or 100 but it is crazy to have to always have to remember which. Insist on kPa; MPa. For unit weights, use kN/m3, not g/cc or kg/m3.
Best regards
RE: Soil Pressure - U.S. to Metric Coversion Question
N/mm2 is actually MPa. And for any dynamic calculations, we still have to consider mass as well as weight, so kg/m3 will have to stay in our vocabulary, like it or not.
RE: Soil Pressure - U.S. to Metric Coversion Question
See what I mean? I have MPa written down somewhere - but it is always a pain to have to find my little crib sheets!! May in dynamic calculations it is easier to use kg/m3 (although, I suppose you could use kN/m3*.981 (or is that /.981??). But for soil weights for stability calcs, settlements, etc., kN/m3 is best!!
By the way - the CRC Chemistry handbook has a great listing of really wierd conversions besides common ones!
Take care - best regards.