Gusset Base Plate design at brace location 1

[palk7 EIT]

Hi,

I use STAAD pro and RAM connections interchangeably. When I design the base plate with a gusset connection in RAM at the bracing locations. RAM imports the loads from the column axial, V2, & V3 shear forces, and the bracing axial force. The connection is fine, however, when I go and see the support reaction (the particular node) at this joint, I have huge lateral forces (huge than the minor V2 V3 shear forces from the column that are imported for the design). These huge lateral forces doesnt show up in the base plate connection..

Does it mean that the base plate with gusset connection is only for the member forces from the column, brace and the support reactions (huge lateral foce) should be used for footing design and stability?

 

[palk7 EIT]

I apologize, it does include the lateral loads (Vu3) in the huge order in the connection design. However in the design verification at concrete base it only checks the (axial bearing), what about the shear breakout in concrete 51 kips in LC41. I could be wrong this is my 1st time with braced base plate connection, please guide me if my understanding is wrong. Attached the connection detail.

 

[driftLimiter]

Some internal QA/QC is needed on your end before you can address the issue.

A good free body diagram of the forces coming into the joint should give you the answers you need.

The baseplate needs to transfer all of the member forces to the foundation. There shouldnt be a 'huge' force that you simply ignore because the program is not importing it properly.

I think you need to assess what you think the forces at the joint should be (not what the program is telling you). Then check your design workflow to ensure that the forces are close enough.

 

[palk7 EIT]

Driftlimiter, that was my concern, and it raised the alarm that those shear forces are not being transferred to the anchor for checking in concrete. It turns out I need LRFD combinations and design for the LRFD base plate and anchor elements for the program to check those design checks. I had ASD combinations, hence the problem!