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[ramu_se]

Dear Sir,

While designing Eccentric footing with a strap beam,

No need to consider a Two-way shear check since the strap beam is
provided.

In strap beam design bending moment calculation we need to take column load with eccentric distance or the footing width?

Along with the bending moment, the torsion moment needs to be calculated?

Since we have a footing slab, strap beam needs to be designed as a T-beam?

I have done half of the calculation, kindly guide me to proceed further.

Thanks & Regards,
Ramu.

[vikram.jeet]

Er ramu ,,

1. Just to simplify  - Please design footing considering Overhang of   ( 1.22 - col dim ) for shear as well as bending ,, provide uniform mesh at bottom .
Make check for punching shear in footing .
Strap beam is provided to resist eccentric moment .

So moment in strap beam = 30t Ecc col load x (1.22/2- coldim/2)
Design strap beam for this moment,   tension top . Top reinf be provided ,, bottom bars may be nominal . Shear reinf in strap beam is nominal since footing is designed for same ,, beyond footing zone of 1.22m here ,, shear may not exist and top moment becomes uniform in simplified approach . If u want be more rigorous see book calcs ,,

This is just simplified approach ,,but for academic purpose see calcs in text book which may result in nearly same requirements .

[vikram.jeet]

Er Ramu,,
Let me modify my mail :   dted 7.1 23
In case you chose to design edge footing supported on strap beam,, then you can design accordingly  in  cross direction.

But step 4 by you is ok except no need to add self wt of footing as it will be nullified by its base reaction  ,, Pl draw strap beam upto inner column,, subjected to eedge column load verically down at edge,, reaction from edge footing vertically up.   BM at inner face of edge footing   will equals eccentric moment on footing.

In this case full shear to be borne by strap beam  and stps will be heavy. Only benefit is that edge footing will be little thin.

But simplified approCh as discussed in prev post is better,, since edge footing is itself sufficient  except ecc moment borne by strap.

[ramu_se]

Thank you sir for the explanation.

Revised the calculations as per your instructions(simplified approach).

Shear force  = total load on column (300kN)
Factored shear force = 300x1.5 = 450kN. which is quite high.

Kindly check the calculations.
Thanks & Regards,
Ramu.

[vikram.jeet]

Er Ramu ji

On Forum,  it is not appropriate to check any calculations ,, and views on design philosophy can only  be discussed ..

Hope you will bear with this . Please discuss it with your senior str Er of firm OR send it to the proof  Consultant if any .

We  provide opinions and views based on our experience ,,  But at the end of day it is the driver Structural Er to satisfy himself first ,,

With best wishes and regards

[ramu_se]

Ok, Sir. Thank you.