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I am a PE in three provinces of Canada. In a nutshell, you get more $$/hour and take responsibility for everything you design. If anything goes wrong, you are on the hook. 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.

Assalam-o-alaikum! Punching shear in raft footings, is often tackled by providing thicker slab portions under heavy loaded columns, as already mentioned in previous posts. Generally length and width of raft can be increased suitably keeping in view allowable soil bearing capacity, provided space is available. However, in many cases this area extension might not be possible beyond the outer faces of exterior columns (being at the property line). Regards.

You should always do your due diligence. Most senior engineers in Pakistan have limited knowledge. Never listen to such people as they breed ignorance. Thanks.

Assalam-o-alaikum! For knowing the benefits of getting a PE Lincense in the USA, go to: http://www.kaplanengineering.com/resources/exam-information/ Details regarding PE exam are available at: http://ncees.org/exams/pe-exam/ Regards.

Give the architect a call or talk to the client about what finishes he plans to use. You can't just assume anything. You need to have a basis to go back too. Thanks.

Rizwan Mirza should be doing everything and anything.

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.

Dear Engr. Waqas, I dont think 2" expansion joint will be sufficient for a building in seismic zone 3. But other things do matter as well for example; how many stories? etc In ASCE/UBC/Australian codes, seismic separation should be SRSS of inelastic displacements. that is delta = [ (inelastic detla of building 1)² + (inleastic delta of building 2)² ] ^ 0.5 Remember that these delta values should be at the same level. For example if a building is 9 story high and adjacent building 3 story high. You have to calculate expansion joint at level 3 of both buildings. Ofcourse you need to check expansion joints at all other stories too (Level 2, Level 1 and basements) if displacement on those levels is more than level 3 (due to high seismic weights or anything). Please also remember that usually in softwares you consider X or -X directions for seismic analysis (and Y / -Y) take the max from X and -X and multiply it with Cd/I (for ASCE) or 0.7R (for UBC) to calculate seismic movement of that building. Do this for the second building and then SRSS will give you final value. HTH

sending you cad drawingsPRO DWG 3.dwg

Experience seldom helps in studies ...... vice vesra