14 story braced frame shear reaction 2

[Galambos]

given a 14 story steel structure with braced frames (R=3), is there a method used to transfer shear from the columns to the foundation more often than others?

i am familiar with shear keys and aisc's stance on transferring shear through anchor rods, but was curious what others would do in this situation.

i'm not a fan of the shear key after seeing it constructed. the tolerances for concrete are very different than steel and the bite of the key into the pier doesnt always work out the way it was intended.

i have considered welding plate washers with standard sized holes to the base plate, but wanted to hear some other opinions.

 

[JAE]

We've used traditional anchor bolts used to resist the tension uplift.

For the shear we:
1. Add embedded plates (with headed concrete anchors) on either side of the base plate, embedded in the top of the concrete.
2. Welded vertical steel plates to tie the base plate edges to the embedded plates - just to take the shear.

 

[WillisV]

We use a similiar detail to JAE but everything is post-installed to the workers have to remember to put in embeds or get them in the right position.

We just take L5x5 angles after the columns have been erected and prior to grouting, set them directly next the the baseplate, screw them into the foundation with Titen HD screw anchors or soemthing similiar, and weld the vertical leg to the baseplates. The angles then serve as little side forms when they flow the grout in under the baseplate.