DEFLECTION ANALYSIS OF A 12 METRE CONCRETE BEAM 8

[azh]

I was doing a deflection check on a 12 metre reinforced concrete simply supported beam.In the code it says compliance with the span/ effective depth ratio (20 for simply supported) will generally limit total deflections to span/250.
When I checked the actual span depth ratio for a 1 metre deep beam, the result was simply 13.3 ( ie 12000/900 ), hence this means this is well below the allowable basic span depth ratio of 20.
However, when I used the formula 5 wLxLxL/(384EI), the max deflection came out to be 54.6 mm, whereas, as mentioned above, the allowable limit is span/250 = 48 mm.

Do I have to increase the beam depth ?

 

[azh]

Thank U Sir. You are right I am a relatively new engineer.And I am working with a government agency, which we termed PUBLIC WORKS DEPARTMENT. I was in Manchester University ( not UMIST)doing my civil Eng degree.

Just got back from the office, and used the unfactored load for the analysis.Better results !