Embedded reinforcement/bar for anchoring

[sonyablade2010]

Dear All, 

I would like to know is there a way in RSA to perform the calculation of embeded steel/rebar anchoring caluclation ?  I thought that stiffened column base connection solver can be used for that purpose but it really under estimates the capacity when its in tension, so it doesn't seem suitable. 

My goal is to perform anchorage calculation of horizontal staircase girder (NPI300 with head plate ) ,   to existing concrete structure, how many anchor rods/class/etcc and layout need to be decided how can I perform soemthing like that in RSA.

Regards, 

[sonyablade2010]

Any idea on this one, 

[Artur.Kosakowski]

Hi @sonyablade2010

I would like to know is there a way in RSA to perform the calculation of embeded steel/rebar anchoring caluclation ?  I thought that stiffened column base connection solver can be used for that purpose but it really under estimates the capacity when its in tension, so it doesn't seem suitable. 

Why do you think it underestimates this capacity?

[mustafahesenow]

Hi @sonyablade2010

This kind of calculation of anchoring on existing RC member is not available in Robot and it has 2 types (mechanical or chemical) Anchors and it have a lot of variable choices depends on bolt type and chemical content to be provided for such this anchor and Its provided 

by suppliers such as Hilti or Fischer .

[sonyablade2010]

@Artur.Kosakowski  When the column element is subjected to compression(Axial+bending_x,y and Shear_x,y,  combined forces)  which is usual case, base plate joint produced results are satisfactory, but if I change only  Axial to tension in that combination (+ signed 160kN), which is exactly my case, then the joint capacity immediately changes drastically at the following equation with ratio 3,11

Connection fails at :

M_j,Ed,y / M_j,Rd,y + M_j,Ed,z / M_j,Rd,z ≤ 1,0

With respect to above, I'm allowed to assume that axial force is governed in connection. In order to verify that by quick engineering judgement (please see the image at the attachement for bolt layout ). For hand calculation I assumed that  the axial force and bending moment is acting on section, found the combined moment of inertia of bolt layout and from. 

sigma =  All_Axial_Force/Area_Of_All_Bolts + [Momen/Inertia] * Outmost_Bolt_Distance, 

   sigma per bolt becomes equal to 3,94 ton to the outer bolt.  Which is satisfactory. even for the conrete  pryout effect.

Concrete tensional stress is approx for C30 = 10kg-f/cm2, based on the pryout cone 10cm depth and cone is = pi*r*l * 10kgf-/cm2 = 4,45 ton per bolt.

 which is greater than 3,94. 

Aside from all of this, HILTI software( as @mustafahesenow mentioned the software) also yields satisfactory results, but in RSA even the 250 mm anchor embedement is not enough so based on that I said that somehow RSA underestimates the capacity of anchor embedement.

@mustafahesenow Thank you for the entry point, I 'd have missed the Fischer, thanks fo remainding this.

Regards

[Artur.Kosakowski]

Hi @sonyablade2010

To make sure the small distance to the foundation edge is not a factor here =- could you increase B and L values?

If no change, could you attach this example?