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  1. Today
  2. There are two three columns in a grid ,two are placed in the same line another is to the downward side of the two columns,The two collinear columns are at 5 m apart and the next column is at 1.5 m apart tentatively.What the engineer has done is,tie the two collinear columns with strap beam,because the edge is on the property line and moreover at a large distance apart and the interior column is combined with the downward column (the downward column is at property line too).Is it possible to use combined footing and strap footing at the same time?My concern is ,the engineer has not separated out two designs for the combined behavior of the footing ,he has designed it as separate,one is strap footing ,the other is combined. Is it because ,the pressure intensity disperses over large area ,so he has taken it as single behavior?Wont there be site difficulty during casting?And is the design ok??I have attached the file herewith.
  3. Final Year Project

    See this topic: It depends. I have seen some embassies get blast wall designed considering the terror threat they face. Search the forum.
  4. Final Year Project

    Actually my team is insisting to work on this topic but my interest is in hydraulics...is there future of hydraulics in next 5 yes?
  5. why not? any good reason why it can't be used?
  6. Is it possible to use AISC360 in building design in Pakistan? and AISC360 accredited in Pakistan?
  7. Final Year Project

    Blast "proof", nothing is proof, i guess. Second, doing blast analysis in bachelors is in my opinion too much work/understanding. Question: What you want to pursue in future (atleast next 5 yrs)? hard core structural engineering design? if yes, then do something related to a bigger scope giving you an overall understanding instead of a specialized topic. if no, you could do anything then. Just my opinion.
  8. Thanks for sharing, will study more about this. The usual practice is to assume hinge for isolated foundations unless they are massive, and fixed for raft in analysis.
  9. Final Year Project

    AOA I want to work on Blast proof concrete as my final year project.. Is this suitable for final year project?? plz guide me n give me new ideas regarding final year project
  10. Final year project

    I am also facing the same thing..plz guide me for final year project related to structures and hydraulics
  11. Yesterday
  12. There is also another point in this discussion. The assumption of a fixed based for isolated foundations is not valid because these foundations are susceptible to rotation. That would mean no moment (there would be some as foundation has rotational stiffness) at column foundation interface and more moment at beam column interface - plastic hinging in beams column joint. Although the original discussion is about developing plastic hinge at foundation column interface but I think the fact that isolated foundations rotate makes these two conditions mutually exclusive (some degree). If the foundation rotates then it is a pinned end and the only forces there would be shear and axial.
  13. The analysis is not limited to high seismic zones and it is also not limited to weaker soils. That is why I posted it. We assume that hinge will form if longitudinal reinforcement of vertical members can develop 1.25fy, but that is not the only criteria. The author says that capacity design approach should be used for proportioning foundation. The proportioning of foundation for the design seismic forces is not enough.
  14. Yes agree with @BAZ that foundation must be strong enough to allow forming hinge at base of column but my point is that this is the usual assumption in normal code based design along with many other assumptions. Yes, we can go a step ahead to non-linear design and soil structure interaction but usually thats not done. Please correct me if wrong, I think that all is done in weaker soils and high seismic zones, so I personally have not experienced this kind of analysis.
  15. Last week
  16. I found another thread on the forum where isolated foundation rotation was discussed. The author (posted excerpt from Pauley and Priestley ) recommends modelling isolated foundation using a rotational spring to avoid unexpected column hinging at top of lower story columns. FYI, Thanks.
  17. I posted the query because I recently read two articles: one is FOUNDATIONS FOR SHEAR WALL STRUCTURES by J.R. Binney and T Paulay, and the other one FOUNDATIONS FOR CAPACITY DESIGNED S T R U C T U R E S by P.W. Taylor and R.L. Williams. @Rana : This is not enough. These details ensure the development of column hinge at the bottom if it is possible. And that "if" depends on the soil-structure interaction and the strength of the soil. If the soil is strong enough to resist bearing pressure corresponding to forces (axial load + moment) that it may experience when the column will be in inelastic range (capacity design approach), and if you have designed the footing for the moment that it may experience when hinge (capacity design approach) will form in the column, which is, of course, greater than the moment that you will get from ETABS for the design Earthquake, then the hinge will form in the column. If the above scenario is not feasible then you may proportion the footing to allow the rocking behavior so that energy may be dissipated provided footing rotation is in permissible limits, which will depend on the soil-rotation relationship. @umer: In MAT, or other connected foundation types, the third option is to allow nonlinear behavior in the foundation. In that case, the foundation should be detailed for attaining necessary ductility levels. These things are not discussed in the ACI code. I have not read these things in RCC books as well.
  18. Thanks Rana. This would be applicable for all foundations. @BAZ, Sir when you mentioned isolated foundations only, is there any specific item other than what Rana has described that you would were thinking. I don't have any idea about this topic other than that isolated foundations can rotate but don't know how that would be related to this discussions. Thanks.
  19. Modeling of pile with soil behavior

    thank you for your guidance
  20. what else is required in conventional codal design other than proper detailing and developing bars for ductility? I found this useful; https://www.housingauthority.gov.hk/tc/common/pdf/business-partnerships/resources/concrete.pdf
  21. 2D-Plate Analysis -Safe

  22. Look for the staad manuals for software related nomenclature. structural concepts are same and you could refer to any good book on rc/masonry design or can ask a specific question here.
  23. Modeling of pile with soil behavior

    1-as we have To follow simplified approach in structural software to model geotechnical properties,as you are right that modulus of different soil will be different therefore i have uesd a word" accordingly". 2-anyway there are many other ways to incorporate the lateral stiffness/vertical stiffness approxiamately,Thanks .
  24. RT @FaraQureshi: People of KPK are dying of #Dengue, calling @CMShehbaz for help and @ImranKhanPTI is searching new paradises #Priorities !…

  25. Can anyone tell me how to do traditional Design of residential buildings in Pakistan using STAAD PRO? Any tutorial will be appreciated
  26. Does anyone practice the design philosophy that ensures the formation of plastic hinges at the bottom of the column, near the foundation, for isolated footing?
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