Jump to content
  • Welcome to SEFP!

    Welcome!

    Welcome to our community forums, full of great discussions about Structural Engineering. Please register to become a part of our thriving group or login if you are already registered.

Sign in to follow this  
BAZ

Incorrect floor framing

Recommended Posts

The beam with larger depth should be the main beam, and the beam smaller depth should be the secondary beam. By main beam, I mean that the beam has ability to attract forces from adjoining members because of its larger stiffness.

Keeping that thing in mind, secondary beams should have been transferring the reaction directly to main beams, and main beams should have been transferring the loads of secondary beams, which are carrying the load of metal deck and the live load, to concrete beams.

In the figure, they have placed larger and smaller size beams in the same directions. If smaller size are able to carry load, as is evident from the standing structure, why use larger beams. They have wasted material.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Our picks

    • Assalam o alaikum.
      According to ACI 12.5.2,
      development length for fc' = 3000, fy=60000, for normal weight concrete and epoxy less reinforcement, The required development length comes out to be
      for #3 = 8.2 inch
      for #4 = 10.95 inch
      for #6 = 16.42 inch
      for #8 = 21.9 inch
       
      And if in my case, ACI 12.5.3 is not fulfilled, it means now i have to provide ldh as mentioned above. ldh is STRAIGHT EMBEDMENT LENGTH + RADIUS OF BEND + ONE BAR DIAMETER as shown in figure attached. Now my question is, if in my case, main reinforcement of beam is of #6 and #4, minimum column size required will be 18 inch and 12 inch respectively. Lets say by any means, i can not select #4, #3 bars and size of column where bars are to be terminated is 12 inch, how to fullfil this development length???
      • 11 replies
    • Dear all,

      I am trying to design shearwalls through ETABS with temperature load applied over shell. At various location, spandral section fails in Shear due to temperature and piers (sometime in shear, mostly in flexure).  (See Attached Image)

      Certainly all the problem in Shearwalls are due to temperature. I don't want to increase cross section of spandral or pier at some location just due to temperature load case as it will appears non-uniform with rest of the wall. 

      I have seen stiffness modifier affect distribution of forces and also rigid/semi rigid daiphragm assumption. 

       

      Can anybody guide how to properly design the shear wall with temperature load applied in ETABS or share any similar experience. Thanks in Advance.    
      • 15 replies
    • ENGINEERS;
      I WILL LOOSE MY BRAIN FROM ETABS. 
      I DECIDED TO MAKE MANUAL MESHING FROM AREA ELEMENTS BESIDE EACH OTHER AND EVERY HING WAS FINE .
      BUT AFTER DEVISION SAY 7*7 ELEMNTS FOR EVERY BIG ELEMENT AND MAKING ETABS CHECH..................THEN 500 ERROR MESSAGE THAT ALL ELEMNTS ARE CLOSE TO EACH OTHER.  WHAT ARE GOING...... SOMEONE TELL ME PLEASE...... I WILL LOST MY WORK
      • 6 replies
    • Assalam o alaikum.
      I have just designed a frame structure with SMRF. The out put of shear seams weird to me. Column reports design shear Av/s as 0.045. (Images are attached). but when i right click the member, it must show me the most critical case HIGHLIGHTED AUTOMATICALLY. But it highlights load combo 38 (auto-generated combos have been used) which reports Av/s as 0.038. And 0.045 value is at combo 32. Is their any logic behind it?? More over how to interpret this Av/s?? means 0.045 in kip-in units means what? How can i convert this into spacing?? 
      • 9 replies
    • Hello everyone, I hope all of you will be fine. In etabs when we apply Response Spectrum loading on a multistoried building with 2 basement floors. At what floor level this loading will be applied as in equivalent static seismic analysis, we can apply EQX & EQY on any floor we like as this option is available in etabs but the problem is with response spectrum and time history analysis. please if someone knows and have the experince, share it i shall be very thankful.  
      • 5 replies
    • Salaikom dear professionals,
      First of all I would like to express my sincere thanks to the initiators of this forum for establishing such an exceptional atmosphere for knowledge/experience sharing, I it is really useful, In fact since I have found the forum I am mostly online and busy reading the posts. I would also like to thank the members for their professional comments and advice.
      As my first post in this forum I would like to ask the following queries:
      1-After running the analysis and design when I check the DESIGN DATA through Display >> Show Tables >> DESIGN DATA >> Concrete Frame Output, there is no specific message in Column Summary Data and Beam Summary Data, but in Joint summary data it is showing that “Joint B/C check not done”. Does anyone has any idea? I am sharing the ETABS model for your information and easy reference.
      ETABS MODEL.zip
      2- ETABS provides greater area of steel in the upper column than the column at BASE, perhaps due to higher moment. Could someone explain why this is so? In practice should we maintain maximum steel in both stories? Or we shall follow what the software suggests?
      3- Beside considering the minimum thickness required for deflection control of Beam as per Table 9.a Chapter 9 ACI-318 , using concrete crack behavior in ETABS and checking story drift, Do we have to check the deflection of beams for the serviceability propose elsewhere in ETBAS? If yes, Could anyone explain it?
      Regards, and look forward to any explanation
      • 13 replies
    • Posting this thread to break the ice. Modelling domes is very easy in Etabs/SAP. All you need to do is to draw the curvature of the dome in elevation by a series of straight lines, but draw only the one half. Then using the apex at centre point, radially extrude the line say 24 times at 15 degree intervals (or 48 times at 7.5 deg intervals. This feature is under Edit> Extrude Lines to areas. You can further use this geometry for Finite Element Analaysis.
      • 22 replies
    • Hello,
       
      I am designing the mosque in zone 4 . The roof of the mosque is a Truss.I have following questions 
       
      1. Do truss rest on the beam ? if yes .? do i have to assign any support conditions ? or etab will selelct by default.
      2. what will be the grade of steel for the truss ? yield or tensile strength. some one told me go for A 36 ( 36,58)
      • 15 replies
    • I accidentally came across these useful case studies, which, I would like to share. You can use them if you are working on a commercial or residential building retrofitting project. These case studies provide insight about seismic retrofitting and also on analytical methods, that are used for building assessment. I would also like to give due credit to people who are involved in these studies. All these studies were performed under a US-Pakistani Joint Cooperation Project. The details for the project are.

       





       

      6-Storey Mixed Use Building in Karachi.pdf

      10-Storey Office Building in Karachi.pdf

      RS-4 Storey Academic Building in Karachi.pdf

      Five Storey Residential Apartment.docx

      Please visit the thread to download the attachments.
      • 2 replies
    • *SEFP Consistent Design*
      *Diaphragm Flexibility*
      *Doc No: 10-00-CD-0004*
      *Date: August 07, 2014*
      I am writing this article about a very important, but mostly neglected topic of flexibility of diaphragm. I used to assume that all reinforced concrete slabs can be treated as rigid diaphragms. But as it turns out, only the slab with span-to-depth (depth is length of slab in direction of lateral loads) ratio of less than 3 and without horizontal irregularity can be treated as rigid diaphragm. The more important thing is that the span-to-depth ratio and horizontal irregularity is not the only criteria and one other factor also needs to be kept in mind before assigning rigid diaphragm to concrete slabs in numerical model of building.
      Another important concept that I learned, and it was a moment of epiphany for me, is about TRANSFER diaphragms. I had posted a topic “Amplification Of Forces In Etabs” earlier in this forum but we were not able to reach at a satisfactory conclusion. Now, I have the answer to that query: Back Stay effect. Another article is required to explain it , and this concept is not discussed in this article. This article is about flexibility of diaphragm.
      Diaphragms are horizontal members of the lateral-force resisting system of building structures. Their function is to distribute inertial forces, generated at its own level, as well as other levels, to vertical members of lateral-force resisting system.
      One kind of diaphragm only distributes inertial forces generated at its own level. This kind of behaviour is observed in buildings where there is a continuity of vertical members of lateral-force resisting system: building should not have a setback or podium at lower levels, or below grade levels. The other kind of diaphragm, known as “Transfer diaphragm”,

      Read more: http://www.sepakistan.com/topic/1480-diaphragm-flexibility/

      • 4 replies
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By The Architect
      Can the slab bottom reinforcement pass below inverted beam bottom reinforcement?
      Otherwise the slab bottom reinforcement mesh will be lifted up atleast 2.5", thus reducing the design effective depth.

    • By Rizwan Khurram
      Dear All,
       Can any one tell me how to model surge  girder of 18 m span in sap or any other relevant software. 
    • By Ali Shan
      Can some body please give reference regarding torsional design of post-tensioned bridge girders? I have searched through AASHTO LRFD Bridge Design Specs but could not find a valid reference.
    • By saadyounas
      Hi guys
      In the question i have a super T girder with some reinforcement. Ques is I have to calculate compression strength in concrete block using formula C = gamma * 0.85 f'c * b (width)
      what value of b should i use to calculate this compressive force?
      thanks
      Saad

    • By kHURRAM ALI
      ASLAMWALEKUM
       
      IN ETAB MODEL THE SECONDARY BEAM BREAK ON PRIMARY BEAM ,SO THAT POINT LOAD OF SECONDARY BEAM CAN APPLY ON PRIMARY BEAM , BUT IF TWO BEAMS OF SAME STIFFNESS , SPAN AND LOADING ARE INTERSECTING AT THEIR MID POINTS , HOW TO DECIDE WHICH ONE WILL BE PRIMARY AND SECONDARY BEAM , I AM ATTACHING THE ETABS PALN

    • By saleem khan
      i want to model beam whose ends are resting on masonry wall in etabs,if i assign hinge or roller support to end points of beams how the load,moments and shear will transfer to below elements if it is a mulistorey building
    • By Jigger
      Here are a number of questions that I need answered. Help would be appreciated.
      Q1. In ETABS, what if the beam combined fail in Shear and Torsion? Need Solution
      Q2. In ETABS, Obtained moments on both ends on simple supported beams. What to do?
      Q3. Discuss dependance of foundation on bearing capacity of soil in SAFE model? What options do you have if the Bearing Capacity is very low?
      How would you check and find one way and two way shear in SAFE model?
      Q4. Why mass and weight are considered separate in ETABS?
      Q5. Differentiate b/w P-Delta analysis vs Dynamic Analysis?
      Q6. Material properties and strength of Concrete depend on what parameters?
      Q7. What limit "1" in punching shows in SAFE?
      Even if you know just one answer, please reply. It would be very helpful.
      Thank you and Regards.
  • Recent Discussions

  • Latest Forum and Club Posts

    • WA. Dear Junaid, 1. Your research topic is very important, being directly related to the professional engineering practice. Please do share the results & conclusions here, on completion of your research, for the benefit of forum users. 2. For obtaining relevant literature, you may adopt following methods: a. Your university will certainly be having subscription to one or more research publishing websites (like ScienceDirect etc). If so, you may search & download relevant research material from these websites. b. You may also request your colleagues studying in other universities to do a similar search on the websites subscribed by their institutions, in case their subscribed research sites are different.  c. Use Google search (with pdf option) to find out relevant research material from many other resources (international universities, research sharing sites like Research Gate & more), downloadable free of cost in several cases. Wish you best of luck in your research. Regards.
    • @Ayesha As we are using half scaled Model in our experiment so the objective of this similitude study is to determine a set of principles,correlation and conditions upon which our scaled model can be related to the prototype for predicting prototype performance.
    • In order to study the effect/performance of infill walls we are providing infill walls in our half scaled 2-story RC Frame model which we will be testing on 6DOF Shake Table here in Earthquake Engineering Center, UET Peshawar...
    • Interesting. I also don't have any experience with Similitude Study. I am curious to ask that what is the objective of this study?   
    • Wa alaikum us salam, I dont have any relevant info regarding similitude study but I found your research topic very interesting. By the way, Are you going to consider effect of infill walls as well? Best of luck.   
    • AoA , I am going to start my M.Sc. research on "Similitude study of scaled 3D RC Frame for seismic testing on 6DOF Shake Table". Need your expert opinion on this topic. It will be of great help if anyone on this forum have work on Similitude Study and share their experience,relevant research papers etc Thanks
    • Your question is not clear. If you explain your problem in a bit detail, you may get a more specific reply. However, if the purpose of your question is to know about general procedure of interpreting reinforcements given by SAP2000 software, it is given below. 1. When we design a concrete frame in SAP2000, it gives following different types of reinforcement: a. In case of columns, required areas of main (or vertical) steel bars and lateral (or ties) reinforcement. b.In case of beams, results are in the form of reinforcement areas for bottom & top main bars as well as stirrups. 2. Given area of steel for column vertical bars is to be converted to suitable number of bars (using theoretical bar areas, as we do for manual calculations) according to code requirements in such a way that the provided steel area is either equal to or a bit more than the area required by SAP2000. Similarly, reinforcement areas given for bottom & top bars of beam members are converted to suitable number & sizes of bars, such that provided steel area is either equal to or a bit more than the area required by the software. 3. Reinforcement areas provided by SAP2000 for column ties & beam stirrups can be converted to suitable tie & stirrup size and spacing, similar to that explained in the following thread for ETABS case: HTH Regards.
    • How to compute steel reinforcement for a concrete section in sap 2000? 
    • Hello everybody i need a favour can anybody provide me with the following paper, i cannot access it.... Empirical relationship for frequency content parameters of earthquake ground motions by ellen rathje
×

Important Information

By using this site, you agree to our Terms of Use and Guidelines.