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Assalam-o-alaikum! In case of Pakistan, an engineer cannot undertake any professional engineering works unless registered with Pakistan Engineering council (PEC). Therefore registration with PEC is mandatory. General procedure for registration with PEC is as under: A person who holds a Bachelor degree in engineering discipline/program duly accredited with Pakistan Engineering council (PEC) or any International professional body (like ABET, ECUK, JABEE, FEANI, Engineers Australia, and Engineers Canada), is enlisted by PEC as Registered Engineer (R.E). When a R.E has attained a minimum of five years of practical experience in relevant field of engineering from a recognized engineering organization or institution or service and has earned at least seventeen CPD (Continuing Professional Development) credit points, he / she shall become eligible to apply for Engineering Practice Examination (EPE), developed for the assessment of the engineering competence, knowledge and skills of an applicant engineer. A registered engineer may qualify for registration as Professional Engineer (P.E) after qualifying the EPE, which may be arranged and conducted through local or foreign services hired or availed for the purpose. Regards.

Assalam-o-alaikum! If you want to get to-the-point advice, you should provide some basic information about your structure (like building type, number of stories, bay spacing, seismic design category etc.) along with some sketch, to understand the situation and nature of problem. Regards.

Assalam-o-alaikum! Very nice, Sir Umar! Thanks for sharing. Regards.

Thanks EngUzair, and well done sir Umar

Assalam o alaikum, I am designing a concrete frame in seismic zone 4 to which I have assigned seismic design category E. I ave insufficient data for site soil so I have assumed soil type Sd. Now I m to ask that IBC 2009 1809.13 says,footings must be interconnected. Whether this requirement only for Site Classification as E,F or it is for all site classifications? Moreover this requirement means tie beams must be at footing level or Tie beams provided at plinth level also satisfies this provision? Thanks.

W.s. 1809.13 Footing seismic ties. Where a structure is assigned to Seismic Design Category D, E or F in accordance with Section 1613, individual spread footings founded on soil defined in Section 1613.5.2 as Site Class E or F shall be interconnected by ties. Unless it is demonstrated that equivalent restraint is provided by reinforced concrete beams within slabs on grade or reinforced concrete slabs on grade, ties shall be capable of carrying, in tension or compression, a force equal to the lesser of the product of the larger footing design gravity load times the seismic coefficient, SDS, divided by 10 and 25 percent of the smaller footing design gravity load. Site Class is specific to E or F. Individual Spread Footings founded on soil shall be interconnected... ; Ties shall be at foundation level. Thanks.

Do design the raft for punching reinforcement if you cant provide enough thickness. Just because you have detailed a portion of raft as a beam doesn't mean it will behave as beam. Such concepts are a total misconception. Similarly, a lot of people go for 'concealed beams' in slabs which is totally useless. Like Rana said, increase your thickness locally or design it accordingly. Thanks.

Just draw a line element for punching. It will not calculate the punching and design shear reinforcement for beam for required forces. Otherwise just increase localized thickness under the column for punching. Its a common practice in raft construction.Top of these isolated footings and raft will be at one level.