base plate connection.

[mansoor ck]

Dear all,

i am having a doubt on base plate connection design. here there is a tube section of (150mm X 100mm x 5mm)is connected to the base plate of 300mm x 200mm . in the design the support is considered as a pin support. in that case whe it comes to the detailing side , " where shall be the location of bolt".

thank you in advance.

 

[BAretired]

How is the plate oriented relative to the HSS? If the long dimension of the plate is parallel to the long dimension of the HSS, you don't have much choice in where the anchor bolts are located. But, in any case, who cares? You have designed the connection as pinned and will no doubt get some restraint from the anchor bolts. That is quite normal and results in a lower moment at the top of column than your design indicates.

BA

 

[JasonMcKee71]

You shall calculate the rotational stiffness of the connection and classify it to nominally pinned, semi-rigid or fixed accordingly. Then the analysis model shall be revised correspondingly.
Generally, placing bolts closer to each other makes the connection more flexible in terms of stiffness, but this has to be reconfirmed by calculations.

Jason McKee
proud R&D Manager of
Cross Section Analysis & Design
Software for the structural design of cross sections
Moment Curvature Analysis
Interaction Diagrams
Reinforcement Design etc.

 

[SAIL3]

I agree with BA...the only time I consider a moment @ the base in similar situations is when there are post-installed anchor bolts involved and I check the bolts assuming there is a moment present....I do this because I have never fully trusted the post-installed anchor bolts as their capacity depends greatly on the their proper installation on which I usually have little control...