Wide rc beam on small column 1

[albert1]

Hi

Recently i design a wide rc beam 2.4m x 0.6m with supporting one way rc slab. Should i use the normal design method of RC beam with ratio of width /height <1.0 to design wide beam ? how does the load at the overhang of beam near the small column transfer to the column if we use normal conventional method of designing the wide beams supported on small column. Any suggestions ? Thanks

AL

 

[DaveAtkins]

Typically, one way shear is critical on r/c beams. In your case, punching shear is more likely to govern. I would also check a short portion of the beam bending in the 2.4 meter direction over the top of the column. What you are designing is somewhat similar to two way slab construction, in the way load enters the column. DaveAtkins

 

[albert1]

Thanks for the tips, Daveatkins.
Refer to the same topic, how long is the short portion of beam bending in the 2.4 meter direction over the top of column need to be used for checking. Would the wide beam subject to torsion when one side of one way slab is loaded with live load ?

 

[DaveAtkins]

I'll answer your second question first. The large beam and the two adjacent slab spans will share any torsion according to their relative stiffnesses (the torsional stiffness of the beam and the flexural stiffnesses of the two slab spans). The answer to your first question is: use engineering judgment. Certainly using only the width of the column is conservative. But perhaps using the width of the columns plus twice the effective depth of the beam is reasonable, as well. DaveAtkins