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About ReinisGailitis

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  • Birthday 09/25/89

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    Riga, Latvia
  1. What do you mean by r/f? I'm not 100% sure about the upper limit on the strut angle (>=65 degree you mentioned), but I suspect it is more on a conservative side so that you wouldn't underestimate tension in the tie. Cheers
  2. Hallo. Read some literature on load path method in strut-and-tie design. Also, check information on correct strut-and-tie models for pile caps - you shouldn't assume that the horizontal strut is lying on the interface of the column/pile cap - it should be positioned inside the pile cap. Cheers
  3. Hallo. Strut and tie modeling is a complex design method which requires not only a good understanding of structural behavior but also knowledge in the application of the method. The method is based on the lower bound theorem of plasticity so there is an almost infinite number of solutions possible - design engineer must determine the best possible based on his or her knowledge - no software can apply engineering judgment. I would suggest you to thoroughly study strut-and-tie modeling and after some time you should be able to do the calculations by yourself. I'm pretty sure for now that I'll never leave strut-and-tie design to a software - I'll always do it by myself. Cheers
  4. Just remember that those are engineering calculations, not exact math and whatever you arrive at is only an estimate produced by particular assumptions and input data, which in general have some variation. If I'm designing a "rigid' base I prefer to design for both limit cases, thus assuming a pinned base as well as fully rigid, that way I know I'll be somewhere in between. In general deflections for the pinned case will be the most onerous so I check if they're ok for that case. Cheers
  5. Read through this book - - there's a lot of good information on the matter. Anyway, lateral and torsional restraint is always recommended although you can only have lateral restraint. In such a situation elastic critical moment Mcr will be smaller compared to one in similar situation with torsional restraint added. In such situations, you have to calculate Mcr with appropriate "analytical" or empirical methods. Although I would always recommend using freeware "LTBeamN" where you can precisely model support/restraint condition in a specialized FEA package. Cheers
  6. Then it seems that you should multiply the k16 value as you proposed in your last post, although i haven't seen specific information on this issue, so I'm not sure. Cheers
  7. No, the K factor which goes into the span-to-eff.depth calculation method (the table 7.4N of EN 1992-1-1). Cheers
  8. What do you mean by the same row? Do you mean that there are 3 or 4 anchors on each side of the flange?
  9. Yes, that is correct as far as avoiding cracking in the steel. You still probably would have to check concrete crushing (bigger mandrel diameter) for the L shape bar situation. Not sure what you mean by this.
  10. In essence, yes, it does behave differently, although, in reality, the difference should be smaller than the one prescribed by design codes, as there should be at least some margin for error in the assumption. Yes, use the largest thickness to determine strength of steel member. Cheers
  11. Karuba, once again, I refer you to EN 1992-1-1, section 8 - detailing of reinforcement - you can read through it and arrive at the answer on your questions afterwards by yourself. Do you really want me to go in there and quote all the requirements for you?
  12. Yes, in a simply supported slab you usually check ULS bending and shear, whereas in SLS you check stress limitations, crack widths (or the simplified requirements) and deflections. If you have particular situations which require design by strut and tie models, then that's a different story. I don't use 7.4.2. as it has been shown previously that the method is unconservative in some cases, especially if you don't limit the factor by which you take into account actual stress in the tension steel to 1,5, as per UK NA to EN 1992-1-1. Anyone designing flexural members to EN 1992-1-1 should read "Comparison of deflection calculations and span-to-depth ratios in BS 8110 and Eurocode 2" by R. L. Vollum. To note, I have never ever found a situation where actual calculation by simplified method (using the bending moment at the span for curvature and using factor K to account for shape of bending moment diagram instead of integration) also taking into account curvature due to shrinkage would have yielded a thinner slab than the span-to-effective depth ratios, so I don't believe that method is conservative. And I'm never even taking K>1, only K=1. Also, I'm not sure it takes into account curvature due to shrinkage. I don't use that span-to-eff.depth method for mainstream design, only for preliminary, and also with caution. There are many books and examples on many different topics related to RC structure design to EC, but not many specifically about creep and shrinkage effects beyond deflection calculations. Cheers
  13. Hallo. I'm not sure about the problem - a sketch would help, though. Best of luck!
  14. Hallo, and welcome to the forum! In general, it is accepted that one should use the thickest part of a rolled section to determine yield strength of the member. For welded sections of course one can assume different strengths, although again, it is usual to assume the lowest one. Cheers
  15. I think my first response perfectly answered you question. I may have added that EN 1992-1-1 is where you should look for specifics to Eurocode. But beyond that, I don't think that anyone should have quoted code requirements in this case - if internet is available to you there should be no problem for you to read them on your own.