Threaded Rod Welded To Plate Material
Threaded Rod Welded To Plate Material
(OP)
I am working on checking the capacity of a provided detail for a silo base attachment. In the provided detail, 1" dia. bent rod was welded to a plate and this was then cast into the concrete. The silo would then be welded directly to the plate. I have substituted heavy hex bolts instead of the bent bar. However, I have been unable to determine how to calculate the capacity of the anchor rod/weld connection. Any thoughts or comments on where to find guidelines relating to a connection like this? Please see attached existing detail.






RE: Threaded Rod Welded To Plate Material
Draw the welded detail full size, the bottom of the plate, the bolt and the two sections of fillet weld, a cross section through the center of the bolt. Draw in the two fillet weld throats, find the center of the throat length on both throats, and measure btwn. them. This is (bolt dia.) + (.707 * fillet leg size) and defines the weld dia., which then defines the circumference of the weld. This times the throat dimension, times the allowable weld stress for the welding rod being used, is the capacity. You might want to use a slightly smaller circumference to be conservative, and use two bolts per plate.
RE: Threaded Rod Welded To Plate Material
As a checker you might alternatively consider rejecting the drawing and request that a more conventional material and anchor be provided like a heavy hex head anchor rod welded to the bottom of the plate. There are lots of tools to easily check this configuration.
RE: Threaded Rod Welded To Plate Material
CAB--I should have been a little more clear defining what I am doing. The detail was provided to us by a contractor who would like to install a silo using this detail from a previous project. I am responsible for this project and I am running the calculations on the connection for this particular silo application. Therefore, I am not simply checking someone else's design as I erroneously stated originally but rather designing the connection to loosely follow the detail provided.
RE: Threaded Rod Welded To Plate Material
RE: Threaded Rod Welded To Plate Material
RE: Threaded Rod Welded To Plate Material
Another nut with or w/o an anchor plate can be cast into the concrete.
Heavy hex nut develops the full strength of most rod material.
RE: Threaded Rod Welded To Plate Material