www.sefindia.org

[vikram.jeet]

(To be continued fm previous post s) :

Wisdom beyond calculations :

(iv) Provision of stirrups in beams having slab on one side I.e end beams  -  slab being monolithic , though designed with this edge discontinuous ,, will have partially fixity while detailing reinf . Hence it will cause torsion in beam which in practice is not worked out ,, hence this compatibility torsion needs to be covered in detailing by providing stirrups spacing lesser than reqd ,ie slightly  higher shear reinf ,, as as per IS  456 , this being compatibility torsion (not equilibrium torsion) ,,can be taken care by minimum shear reinf to resist torsional cracking .

(v) Provision of stirrups  in Main beams supporting secondary beam on one side only  - This case is similar to above one ,, here though secondary beam  is designed as simply supported ,, but it is monolithic to Main beam ,, and some partial fixity is created due to top bars embedded in Main beam . This causes torsion in Main beam . Generally in modelling the connection is input as pinned . Therefore there is need to take care of this compatibility torsion through little higher shear renf (stps) .
Easiest way adopted by  some designers is ,, to ignore( tc bd ) relief while working out shear reinf of Main beam .

( to be continued)

[vikram.jeet]

(To be continued from previous posts )

Wisdom beyond Calculations
(vi)  Provision of Stirrups in Mid landing beam and Floor beam ( Floor beam without slab on other side) supporting stairs flights ,, - This case is also similar to (iii) , but due to higher DL+LL in stair waist slab terminating at these beams,, twisting tendency is substantial,, though it is compatibility torsion (since stair waist is designed treating simply suported) .  It is wise to ignore tcbd relief while working out shear reinf. Also since stair waist is folded slab,, designed fully as flexural slab,, theoretically there won't be any horzontal thrust on beams,, but there is possibility of some mixed behaviour causing horz force and minimum side face reinf, to beams supporting stair waist , can add to durability.

But these are personal views,, and shall be ignored if otherwise.

[vikram.jeet]

Wishing All members of Structural Engg Forum of India,, a very Happy, healthy and joyful new year 2023,,

[vikram.jeet]

Cheating with Structural Engineers :
(A)
If an engineer of structure is working in Govt,, Semi Govt,, MNC,, or Organised set up,, there are no chances of technical cheating,, Drgs are mostly followed in toto due to QC.

But if Structure  engineer in small set ups with small builder s  /contractors, in present times can be cheated on pretext of structure drgs. They may follow only general arrangement,, column positionings but may technically cheat in terms of steel reinf provisions,, footing sizes,, non provision of strap beams at foundation level for edge columns,,  as everything got concealed ..

Engineer while providing drgs on personal basis to any owners ,, Friends,, needs to be careful as drgs will be taken for records purpose only and actual implementation (except str GAD) will be  different for steel reinf provisions and foundation as discussed above. SE cannot visit everywhere and especially in such works, there are good chances of technical cheating.

If tomorrow some problems ,, they will blame SE as his drgs are in record.

Seen it and stated above,, if,, otherwise ignore

(To be continued)

[vikram.jeet]

(Continued from previous post)

Cheating with Structural Engineer :
(B)
Another form of technical cheating is raising more storeys than that for which structure foundations and columns (& beams) are designed. Any extra storey not only increases weight on structure, but also EQ forces become higher and put everything viz Foundations, plinth beams floor beams in range of NOT OK.

SE must clearly mention in Foundation plan  as well as notes in foundation drgs regarding Nos of stories, the str being designed. This is very important,, but now a days mentality is totally indifferent .

Any light weight sheet roofing could be permitted   but not more storey/s.


However, if Structural drgs of foundations clearly mention Nos of Stories,, there is no problem for SE as the fact of raising more storey/s by owner is not concealed one and visible.

(To be continued)

[vikram.jeet]

(To be continued from previous posts)

Cheating (technical) with Engineer of structure :
(C)
One more  situation where there is possibility of cheating  is in Footings of uniform thickness (not tapered) ,, Now a days footings are provided with uniform thickness and tapered footings are less common,  reason being full footing rectangular section width is available for bending and shear along with thickness being uniform at deff,, easy for site also to pour uniform thickness

The possibility can be there that  SE designed flat uniform thick footings shown in drgs,, but at site many brains start working smart by providing tapers in footing contrary to drg detail. This will create footing not OK in shear as well as bending.

This will got be concealed in ground.
Just few situations where SE needs to be aware,, and  special notes can be given but cheaters do not care.
With remote monitoring thru photos SE must remain in touch with site during foundation stage.

[vikram.jeet]

Importance of Mentor in Structural design field :

For engineers aspiring to become good Structural engineers ,, it is very essential in the initial career, to work in a reputed Design Consultancy having Structural experts . In association and guidance of a good Mentor/s  ,an  engineer can groom much better, but alongside passion for design work,,  continued self studies,  creativity,,  structural behaviour  imaginations ( now a days deflected shapes are available on computer) . Querries in the begining are much more with a design engineer but as he attends to various designs,, it get clear with passage of time,, but for that working in reputed design firm is a great blessing where one can work,, think,  and get clear to implement..

Mentors like Dr VK Raina (Bridge expert ), Prof Mahesh Tandon,, and many others practicing in various consultancy firms were/ are highly knowledgeable and practical experts/  teachers,, gurus,, and their guidance is great luck.

But still an engineer of structure has to convince own self before releasing designs and Mentor 's guidance must be analysed in self,, though it does not mean any dis - respect snd apprehensions need to be discussed ..

Just a broad view in narrow lane