H-Pile in rock
H-Pile in rock
(OP)
When designing a temporary soldier piling/lagging system where rock is encountered below the excavation/dredge line, what are reasonable Kp values, assuming the h-piles are set in augered holes filled with lean concrete? Any reference sources you can suggest? Thanks you.





RE: H-Pile in rock
AASHTO Standard Specifications for Highway Bridges 17th Edition or LRFD 3rd Edition have guidance.
For permanent walls, AASHTO allows a total force per discrete vertical element of Fp, such that:
Fp = sD*(D+b^0.5)/[1+tan(B')]
where
s = unconfined compressive strength of rock mass
D = embedment depth of element in competent mass (AASHTO recommends discounting top 1 foot of embedment for permanent walls)
b = width of vertical element
B' = angle of dredge line measured from horizontal (sloping downward away from wall is considered positive angle in this case)
Determination of 's' can be tricky, as many AASHTO formula assume a RQD of 60%+. If the RQD is less than this amount, it is unclear what is the best course of action.
Hope this is helpful.
Jeff
Jeffrey T. Donville, PE
TTL Associates, Inc.
www.ttlassoc.com
RE: H-Pile in rock
Check out FHWA's Geotechnical Engineering Circular No. 4, FHWA-IF-99-015, Ground Anchors and Anchored Systems.
RE: H-Pile in rock
RE: H-Pile in rock