PowerStroke79_PE
Well-known member
- Joined
- Apr 29, 2013
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I'm designing a CIP Concrete Drill Shaft and I have a Geotech report that is assigning 10kip/sf for end bearing and assigns .3 and .7 ksf (depending on each layer used) for allowable side shear resistance.
My calculation gives me a Qb allowable of 99Kip with a FS = 3 and Qs allowable of 10 kip with FS = 2. My question is, could it be that the Geotech is using KSF/ft of depth for end bearing? 10 Kip/sf of allowable end bearing will suffice for the steel post I"m using, but don't understand why its so low. The FS values that im using are designated by Geotech REport.
Diameter of pier is 2ft. and area is 3.14 sq. ft. with no Bell. Total Depth of pier is 20 ft. 10 ft clay and 10 ft sand, with top 5 ft of clay layer not usable for friction resistance.
My calculation gives me a Qb allowable of 99Kip with a FS = 3 and Qs allowable of 10 kip with FS = 2. My question is, could it be that the Geotech is using KSF/ft of depth for end bearing? 10 Kip/sf of allowable end bearing will suffice for the steel post I"m using, but don't understand why its so low. The FS values that im using are designated by Geotech REport.
Diameter of pier is 2ft. and area is 3.14 sq. ft. with no Bell. Total Depth of pier is 20 ft. 10 ft clay and 10 ft sand, with top 5 ft of clay layer not usable for friction resistance.
