drilled shafts containing rebar cages and steel beams

[MOhio]

Is the section modulus for such a composite beam calculated by adding the moments of the rebar and the steal section and dividing by the radius distance to the rebar, or by adding the section moduli of the rebar cage and the steel section?

 

[johnbridge231]

As two materials are ncluded in that crss section (ssteel and concrete), section modulus does not make sense, unless you transform the cross section to an equivalent one of one base material, eg concrete. The ratio between the elasticity moduli should then be used.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html