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UmarMakhzumi

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Everything posted by UmarMakhzumi

  1. UmarMakhzumi
    Could be because of number of reasons.. One possibility is that you are using end length offsets. Design moment should be less than max moment at end in such case.Thanks.
  2. UmarMakhzumi
    8.5 ft below is not at grade so would be raft. Use of SOG depends upon what needs are to be met. thanks
  3. UmarMakhzumi
    You are correct. This would effect the moment results and you need to see the respective moment accordingly. To identify beam leg, just modify one of your legs to be very big and extrude your model. About mirror option in frame section property data, I am not sure about the use of that feature. Thanks.
  4. UmarMakhzumi
    W.salaam Select the Assign menu > Frame > Local Axes command to access the Frame Assignment - Local Axes form. Use 90 degrees to rotate the beam. Then extrude the view to verify orientation. Thanks
  5. UmarMakhzumi
    Slab on grade is a foundation type and the use of the term varies from region to region. I have seen them to be provided normally in Industrial Buildings as floors. They are designed for storage + machinery operating loads like fork lifter etc. Frost Heave is a concern for most slabs on grade. In Pakistan, I have seen some firms providing reinforced slab panels above grade and calling it Slab on Grade. That is a reinforced slab panel not slab on grade. To be classified as slab on grade, the slab panel should be acting as the sole foundation. Thats what I would say. Other may disagree.
  6. UmarMakhzumi
    Ramadan Mubarak to Everyone! Enjoy a month of blessings and peace!
  7. UmarMakhzumi
    All, The attached article provides some insight about the subject program. The article is a very good read. Thanks. Str Eng Considerations PERP.pdf
  8. UmarMakhzumi
    You can keep it unchecked as then stiffness is automatically transformed to account for the offset location of the object centroid by using built in constraints.
  9. UmarMakhzumi
    You can use cardinal points. There is a somewhat similar topic on the forum http://www.sepakistan.com/topic/1449-beam-slab-joint/
  10. UmarMakhzumi
    W.s Bayan, you should always model node to node. If you don't put beam end on the center of column and that distance is greater than merge tolerence for joints, you will have no load transfer. For cases where beams are placed eccentric to column locations, you can use cardinal points to account for the offset/ eccentricity.
  11. UmarMakhzumi
    Lets play with more skins. Its really hard to change one thing in a skin because all other things are related. I will try to find a better skin.
  12. UmarMakhzumi
    Hello Everyone, We have recently upgraded the forum skin. For those of you who prefer the default skin over the current one can do the change easily. Just click on the "Change Theme" link at the bottom left of the page and select "IP.Board" from the pop up menu. Please see the attached image for a graphical explanation. Thanks.
  13. UmarMakhzumi
    Rana, Thanks for your input. The forum is expected to go through major upgrade in upcoming months. I would have to reconfigure and potentially re-buy some skins then. I would keep your input in mind when buying new skins for IP Board v4. This skin was potentially the most decent green coloured skin on the market. What I will do for now is that make a new thread that shows members who are not comfortable with this skin to revert back to default one. You will see a lot more options to choose from once forum upgrade has taken place. I don't want to buy more skins before forum upgrade as skins are only compatible with specific versions of forum Thanks.
  14. UmarMakhzumi
    Please also detail one side of the truss to behave as a roller by providing slotted hole on the plate that would be welded or bolted to plate embedded in beam. You should specify the grade of steel on your drawings so that the contractor is bound to use what you picked. Thanks.
  15. UmarMakhzumi
    1) Truss can rest on any support type: Columns directly or beams. However, It is very likely that it would be supported on columns as trusses are generally provided to cover extra long spans. If you are supporting it of a beam, make sure you do your due diligence with beam design. You have to specify the boundary condition based on the kind of connection you would provide to connect the truss with your supporting member. Oversized slotted holes in base plate can act as rollers. 2) Grade depends upon what the market has to offer. Confirm with the rolling mills about what ASTM Standard they roll. Thanks.
  16. UmarMakhzumi
    You comparison would be based on different parameters. You have to be specific in asking for what you need as building codes cover huge variety of parameters. Is this a general study or focused on some special item like Seismic?
  17. UmarMakhzumi
    I don't know about your framing, but assuming that floors would be supported on primary columns, I would model them to get the short column effect. Further Reading (See attachments in the post): http://www.sepakistan.com/topic/4-construction-of-special-moment-resisting-frame/ Thanks.
  18. UmarMakhzumi
    You are welcome Hasan. Dynamic Analysis by Chopra explains the answer in its first chapter where it compares frames with infinitely stiff beams to no beams at all. I believe that you 're using ETABS and the softwares considers the stiffness of frame(beam+column) when calculating center of rigidity.
  19. UmarMakhzumi
    Yes you can. Pick a good book and there are tons of example that show you how to do that.
  20. UmarMakhzumi
    W4x13 column looks thin and light. I can't open your model as don't have Etabs with myself but I wouldn't use any thing less than W12 or W14 for columns. Section should be bit heavy too as heavier sections help in connection design. The checks you need to perform are member beam column utilization checks. Normally programs call such checks as unity checks and show unity ratio. There is a watch and learn video on Csi webpage that shows you how to select a section list and let Etabs select members that would satisfy drift requirements. Rana has made some good points too.
  21. UmarMakhzumi
    Hello Everyone, A very short announcement. You might have noticed, I have trimmed the forum outlook. Some forums have been deleted or renamed and other merged with the existing ones. Also, all non-active moderators have been removed. These days I am looking for a custom invision board skin that is green in color to apply to forum. Also thinking about changing the logo of the forum. Your suggestions are welcome Thanks.
  22. UmarMakhzumi
    Rana has made a good point. You should be careful about what you want to include in your analysis model and what you want to exclude. Without good understanding of meshing and a fervor to model everything would result in highly erroneous models. Also excluding important items like staircases and ramps, would change the response of your structure under seismic loads. There is no rule but thought should be given before setting up the analytical model. Like Rumi said, the art of knowing is knowing what to ignore. Thanks.
  23. UmarMakhzumi
    It may be a bit off topic to discussion, but I would still like to share. I found this article related to assigning base level for seismic computation. Check here: http://www.sepakistan.com/topic/1448-location-of-base-for-seismic-design/?p=3151 With reference to above linked article, the recommendation in such a case would be to have the building analyzed using two staged Equivalent Lateral Force Procedure as per Section 12.2.3.1 of ASCE/ SEI 7-05 Or using Response Spectrum Analysis. If you use Response Spectrum Analysis(RSA) in ETABS, you may have to still keep and use the ELF load cases for foundation design, as signs would be lost after RSA. However a 25% reduction for overturning moment for ELF cases as per ASCE Chapter 12 could be used to massage the situation. Thanks.
  24. UmarMakhzumi
    I came across this very useful article. Here is the summary of the article: Thanks. Location of Base for Seismic Design.pdf
  25. UmarMakhzumi
    For further reading.. http://www.sepakistan.com/topic/4-construction-of-special-moment-resisting-frame/
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