Thru bolt loaded in single shear in concrete Thru bolt loaded in single shear in concrete Polecat (Structural) (OP) 3 Feb 18 05:37 If you have a thru bolt loaded in single shear bearing on a hole in a concrete member, is there any test data or evidence that can show that the stress distribution in the hole is parabolic instead of triangular? http://www.spiraleng.com RE: Thru bolt loaded in single shear in concrete ATSE (Structural) 8 Feb 18 16:03 The stresses in the concrete and the steel bolt are very complex. Probably more parabolic than a nice neat triangle. Just like most other things in structural engineering, we greatly simplify the load distribution, provided there is enough ductility for the connectors and base material to reach "design strength" without fracturing. Just curious - what is the reason to sharpen the pencil for this condition? Usually, this type of connection is over-designed, and for good reason. RE: Thru bolt loaded in single shear in concrete Polecat (Structural) (OP) 9 Feb 18 06:56 ATSE The pencil sharpening is because we are pushing the envelope here. Usually, we are able to cast in a steel pipe thru which the bolt would be inserted. This, of course, increases the bearing area to the concrete considerably. This time, however, it is direct bolt-to-concrete bearing, so we have essentially line bearing right at the outside edge of the hole. That, coupled with a required phi factor of 0.65 in bearing, is really making it difficult to meet the required load. That's why I was looking for some justification for a parabolic distribution so I could use an average stress of 2/3 f'c instead of the 1/2 f'c for a triangle. But, thanks for your input.