Hi!
I am having some issues with the calculations for side-face blowoutfor a group of anchors.
I have that base plate.
A 650x650 mm pedestal, and a 470x470 base plate with 8 anchors.
(I don´t know why, but i can´t upload images right now)
This are the coordinates of the anchors.
As you can seeall the anchors have the same Ca1.
And all of them are tensioned.
When RAM Connection does the verification, it doesn´t compare with the total tension (the sum of the tension in each anchor) that would be 623 kN.
It compares with the sum of tensions in anchors "1", "4" and "7" (276.31 kN)
I wolud say that it is wrong.
Side-face blowout of group of anchors in tension [kN] 409.21 276.31 LC-341-78 0.68 Eq. D-17, Sec. D.4.1.1 SideFaceBlowoutApply = hef>2.5*ca1 = 450 [mm] >2.5*150 [mm] = True Sec. D.5.4.1 Abrg = F2 - Ag = 46 [mm] 2 - 707 [mm2] = 1409 [mm2] Nsb = 160*ca1*(Abrg)1/2*l*(fc/(1 [psi] ))1/2 [psi] = 160*150 [mm] *(1409 [mm2] )1/2*1*(27.579 [N/mm2] /(1 [psi] ))1/2 [psi] = 392.84 [kN] Eq. D-17 Nsbg = (1 + s/(6*ca1))*Nsb = (1 + 350 [mm] /(6*150 [mm] ))*392.84 [kN] = 545.611 [kN] Eq. D-18 HighSeismicDesignCategory ® False fNsbg = f*Nsbg = 0.75*545.611 [kN] = 409.208 [kN]
The ACI318 says that you must compare only with the sum of the tensions of anchors that are near the edges. But in this case i think that would be all of them.
Any ideas?
Tanks to all!
It would help to have your file, and confirm your version. I don't see any prior cases asking about anchor pullout when all anchors are in tension.
Placas base.zip
Its RAM Connection in its version integrated with Staad,pro CONNECT Edition - Version 22.05.00.131.
I don t know ifyou can open the file with the connections. I uploaded a zip file with the staad file and all the other files generated by the program, includin the rcc file.
That works. I'm reviewing your Joint 1, and I'm in different units but for this 8 bolt configuration I can confirm the program is looking at a group of 3 anchors on one side as you noted. This seems logical to me since fixed base plates would commonly have enough moment for three of the bolts on one side to be in max tension and the other side to be neutral (or with less tension). Everything in the code appendix D talks about side face and bolts on an edge. A check for all four sides blowing out is not something we do, but I'm fairly sure such a check would not control anyway.