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.

waqar saleem

Bridge Girder Collapse during launching

Recommended Posts

Salam

Girders of a bridge during launching collapsed. it is reported it happened due to heavy winds during launching of the girders,links for further details are attached.

http://tribune.com.pk/story/1109218/rs330m-jhelum-bridge-collapses-ahead-inauguration/

1109218-bridgecollapsefacebook-146408889

http://www.baaghi.tv/330-million-jhelum-bridge-collapsed-due-to-substandard-material-and-negligence-of-highways-department/

Regards

Share this post


Link to post
Share on other sites

Salam

What i got is that the girders toppled due to wind or any other mistake during launching and their inertial angle changed. Definitely, girders were not designed this way so collapsed in flexure at center region as both ends of girders are still on the supports.

 

Regards

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


  • Our picks

    • AoA all,

      Is it mandatory to do column concreting upto the soffit of the beam in a single pour ?

      What code says about the construction/cold joint location in column ?

      Majority of the contractors are pouring the column concrete upto the soffit of the beam (full height of the column), some contractors leave the column height about 9" to 12" below the beam level and then fill this 9" to 12" column height with the beams & slab concreting. On one site column concreting was stopped at the mid height and the remaining half was filled on the next day.

      Thanks

       

       
      • 4 replies
    • AOA 

      i am facing problems in shear wall design .what are the pier and spandral ?what will be the difference when we assign pier or spandral? without assigning these the shear wall design is incomplete .

      i am taking about etabsv16

      someone have document about shear wall design plz provide it 

      thank you

       
      • 9 replies
    • Salam Members,

      Congratulations to Engineers, PEC has become full signatory of Washington Accord, what are the benefits to Pakistani engineers for this agreement. 

       

      Regards   

       

       
      • 3 replies
    • Please clarify the following confusions one by one:-

       

      1. If we run P-delta analysis in ETABS, then should we ignore stiffness property modifiers for beams and columns? I have heard that if we perform P-delta analysis and apply stiffness modifiers at the same time then the moment magnification process is doubled...?

       

      2. ETABS considers selenderness of a column by applying moment magnification factors. If we run P-delta analysis also, does it mean that the selenderness of column is being over-estimated? I mean once the moments are magnified in P-delta analysis process and again through moment magnification process?

       

      Please help me understand the software myth and clarify above confusions.
      • 1 reply
    • 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
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By UmarMakhzumi
      Hello Everyone,
      Saw this on FB today. Thought would post. What do you think went wrong?
      Thanks.
       

    • By BilalAhmad
      I need your help in deciding whether to go for a RCC basement or Pillar foundation for home construction. I am not a civil enginer. I want the home to be constructed on a strong foundation. I have heard from someone that basement makes the home weak in terms of its foundation. For example in earthquake home with a basement can be more vulnerable to cracks or collapse. I have zero knowledge about construction. That is why I need your help.
      Should I go for a RCC basement OR pillars foundation.
      My only concern is that the home should be on a strong foundation. I am planning for ground floor and in future if needed then first floor. Please guide me which way to go.
    • By waqar saleem
      Dear fellows!
      I have observed that some senior engineers have not been using stiffness modifiers in their designs. What is the concept behind  i am not clear . As we design RC for strength, section is cracked and to cater for this cracked section, property modifiers are used as per
       ACI 318-11  10.10.4 (stiffness requirement)

       ACI 318-11  8.7 (stiffness requirement)


      UBC97 1630.1.2 (modelling requirement)
       so why whole section is considered in design. is there any other logic which i couldn't understand.
       
      Regards
    • By rummaan17
      Dear All, 
      I have designed the bridge between two building. Fixed at one end and roller at the other. The bridge at the roller end, rests on a concrete ledge. I have provided the expansion joint based on the formulation of ASCE for building separation. I have certain queries on it :
      1- Is building separation formulation is appropriate to provide expansion/moment joint in my case?
      2- I am trying to allow the movement through slotted holes in base plate. If my bridge required expansion is 300mm through formulation indicated in Point-1 above, should the slotted hole be twice of it i.e.  2x300mm = 600mm  
       
      I am still unsure as to what size the slotted hole should be ? and what governs the expansion joint of bridge over the ledge end. 
      I am relatively new to bridges. any help would be highly appreciated. Thanks in advance.
    • By EngrUzair
      Assalam-o-alaikum,
      Dear Colleagues!
      The Øresund bridge is an engineering marvel that connects the Danish capital of Copenhagen to the Swedish city of Malmö.
      A cable-stayed bridge runs nearly 8 km (5 miles) to an artificial island where it transitions into a tunnel that runs another 4 km (2.5 miles). The award-winning double-track railway and motorway opened on July 1, 2000.
      For more details refer to the following link:
      http://twistedsifter.com/2015/09/oresund-bridge-turns-into-tunnel-and-connects-denmark-and-sweden/
       



    • 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 Ali Shan
      Assalam-o-Alaikum,
       
      I have modeled a retaining wall in SAP2000. I have got the moments are shear forces in major and minor directions. The wall is also carrying some concentrated axial loads over it (separated at some distance). My question is, how can I check the axial force present along the length of the wall in SAP2000? Like M11, M22, V12, V23, which component denotes the axial force transferred? Also, please give some reference of calculating RCC wall axial load carrying capacity.
      Thanks
    • 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 Beenay Shahi
      using staad foundation advanced, I designed a strap footing for two eccentrically loaded columns(offset of left column=-600mm and offset of right column=600mm) of one bay, 3 storey building with grid spacing of about 14 ft in x direction and 12 ft in y direction. The dead load was about 300kN and live load was about 60 KN and earthquake load was about 40 KN in -y direction with moment about z axis 25 KNm. soil bearing capacity was 150 KN/m^3. I used the load combination 1DL+1LL and 1DL+0.8LL+0.8EL. strap beam was in x direction. I got footing size 1.75mx1.75m. footigg thickness 200mm. no of 12mm bars in x direction=6 and no. of 12mm bars in z direction=23. I got doubly reinforced strap beam with 0.53m depth and 9 inch width. bottom reinforcement=3 no. of 12mm bars top reinforcement=6 no. of 16mm bars. And for shear reinforcement it says:"Since nominal shear strength of concrete is greater than maximum shear force, shear reinforcement is not required". I just want to know are the results I got practical or is it likely that I had made some mistakes. I have doubt whether the following result in right or wrong: the vast difference of reinforcement in x and z direction which are 6 and 23 no. of 12mm bars respectively for 1.75mx1.75m footings. and another doubt is requirement of no shear reinforcement in strap beam. Please help me!
    • By Beenay Shahi
      My Etabs 2015 Gives Very Little Reinforcement For The Columns Of My Rcc Building. What Might Be The Reason. My Etabs File Is Attached Herewith.
       
      https://www.dropbox.com/s/gy1ndwqau32dq64/house%20for%20rupendra%20bista%208.EDB?dl=0
      house for rupendra bista 8.EDB
  • Recent Discussions

  • Latest Forum and Club Posts

    • 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.
    • See this topic:    It depends. I have seen some embassies get blast wall designed considering the terror threat they face. Search the forum.
    • 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?
    • why not? any good reason why it can't be used?
    • Is it possible to use AISC360 in  building design in Pakistan? and AISC360 accredited in Pakistan?
    • 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.
    • 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.
    • 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  
    • I am also facing the same thing..plz guide me for final year project related to structures and hydraulics  
    • 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.  
×

Important Information

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