Coefficient of friction between granular soil and wood
Coefficient of friction between granular soil and wood
(OP)
I am looking for a coefficient of friction between a temporary wood-pad foundation and the underlying granular soil.
Anyone know where I can find information on this? I have tried NAVFAC 7.02 7.2-63 but it does not give a value for wood/soil interface.
Anyone know where I can find information on this? I have tried NAVFAC 7.02 7.2-63 but it does not give a value for wood/soil interface.





RE: Coefficient of friction between granular soil and wood
I would guess that the wood would be relatively smooth. You may want to think about how that will affect the sliding friction - you could start with the soil-steel f-value and work from there.
good luck
Jeff
Jeffrey T. Donville, PE
TTL Associates, Inc.
www.ttlassoc.com
The views or opinions expressed by me are my own and do not necessarily reflect the views or opinions of my employer.
RE: Coefficient of friction between granular soil and wood
Try looking in the NAVFAC DM 7.02. There is a table on page 7.2-63 that lists friction factors between dissimilar materials including a masonry on wood (26 degrees).
RE: Coefficient of friction between granular soil and wood
The friction angle (delta) between timber piles and soil is 3/4 of phi. So, Using 26 degrees as the delta, phi would be 4*26/3, or about 35 degrees. This is reasonable, assuming the soil is properly compacted, and you have the right type of soil. You can refer to Figure 7 of DM 7.1-149, which correlates soil friction angles (phi), with other useful parameters, including relative density by soil type.
Depending on how large your temporary foundation is, the type of soil you have, and your anticipated loads, the friction angle may be an important consideration in your design.
RE: Coefficient of friction between granular soil and wood
RE: Coefficient of friction between granular soil and wood