TIA-222-H, Section 4.9.11.3 U-Bolt Strengths
TIA-222-H, Section 4.9.11.3 U-Bolt Strengths
(OP)
Section 4.9.11.3 of TIA addresses the nominal sliding strength of u-bolts and torsional strength of u-bolts. Cell tower mount's connection to towers are either u-bolts or some form of saddle bracket connection. I have attached a picture of an example of saddle bracket connection. I have not found anything in tia that addresses the strength of saddle bracket connections. Would a saddle bracket connection have the same sliding and torsional strength as u-bolts?






RE: TIA-222-H, Section 4.9.11.3 U-Bolt Strengths
Try to test the software www.asmtower.com to design using TIA-222-H
RE: TIA-222-H, Section 4.9.11.3 U-Bolt Strengths
In my mind these type of connections are universal connection for pipes, vs. u-bolts which are made for a specific pipe diameter. So I believe these type of connections are weaker, compared to u-bolts, for friction strength.
REV-H section 4.9.11.3
Rns=.3(2Tp-Tut)
Rns: nominal sliding strength
Tp: installed pretension in each leg of u-bolt
Tut: exterior tension force applied to the U-bolt assembly
The connection to the tower leg has vertical (Vus) load, a horizontal load that takes away form my pretension in the bolts (Tut), and another horizontal load (I will call it Vx). For this Vx load I get to use the shear strength of the u-bolts. But for a saddle bracket connection the tower leg is not bearing against the bolts. So I do not believe I can use the shear strength of the bolts to resist the Vx load. Saddle bracket connections typically have a radial bend or a v-notch to help resist this horizontal force. Tho I am hesitant to say the v-notch or radial bend allow me to use the shear strength of my bolts. What I am leaning toward doing for saddle brackets is take the resultant force of Vus and Vx and check that against the equations in Section 4.9.11.3.
That is my train of thought and would very much appreciate any thoughts on the subject.