Bearing Plate on Top of Masonry Wall

[ChiEngr]

Hi everybody,

I am looking for some input on the following scenario. I have a 1-story building with Seismic Design Category C. The structure is comprised of CMU shear walls around the perimeter, and the roof framing is steel roof deck spanning to cold-formed steel premanufactured trusses. The lateral load is transferred from the diaphragm to the load-bearing shear walls below through in-plane blocking or transfer truss running parallel over the walls. I have increased this collector force by the overstrength factor per code, and I am providing steel plates between each truss bearing with a couple of Hilti KBTZ2 anchors to transfer the shear load to the wall from the in-plane transfer truss above. I am not sure how the manufacturer will connect the truss to the plate just yet, but I assume it will be a welded connection.

My question is with regards to the anchorage of this plate to the wall itself. I was debating on using headed bolts, but ASTM A307 A bolts do not have a specified yield stress that I can use to calculate the shear capacity of the bolts. Has anybody performed a similar top of CMU wall type connection, and if so, which bolts did you use?

Thanks for your time and help!

 

[dik]

A plate with a couple of headed studs welded to it is a common solution to light loads. The beam is fillet welded to the plate.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[phamENG]

For anchors you should be specifying F1554. You specify them based on their yield strength: Grade 36, 55, and 105 are 36ksi, 55ksi, and 105ksi, respectively.

 

[dik]

not 105... it's not weldable... I'd use headed studs, not anchors. Beams don't often end up at void locations... it's easier to fillet weld the flange to the plate...I don't like using wedge anchors in masonry... only occasionally in the face...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik