Composite Collector Beam Design with Seismic Loads Based on AISC 360-05 / CBC 07 / IBC 09

Designing a composite collector beam with seismic loads based on the AISC 360-05 (American Institute of Steel Construction), CBC 07 (California Building Code 2007), and IBC 09 (International Building Code 2009) involves following the provisions outlined in these codes. A composite collector beam is typically used to resist lateral loads in steel-framed structures subjected to seismic forces. It is designed to collect and distribute these forces to the seismic resisting elements.

Here are the general steps involved in designing a composite collector beam with seismic loads:

Determine design loads: Identify the seismic loads based on the specific design criteria provided by the CBC 07 or IBC 09. These loads include the seismic design category, response spectra, and other parameters specified in the codes.

Select beam section: Choose a suitable composite beam section based on the anticipated loads, span length, and other design considerations. Consider both the steel and concrete properties in the composite section.

Analyze the frame: Perform a structural analysis of the entire steel-framed structure subjected to seismic loads. Consider the lateral load-resisting system, such as moment frames or braced frames, and determine the forces that the composite collector beam needs to resist and transfer to the seismic resisting elements.

Evaluate composite beam strength: Calculate the flexural strength and shear strength of the composite collector beam using the provisions outlined in AISC 360-05. Consider the design strength of the steel and concrete materials, the effective section properties of the composite beam, and the appropriate limit states (e.g., yielding, flexural buckling, shear).

Check deflection and serviceability: Evaluate the deflection of the composite collector beam under the applied seismic loads and ensure that it meets the serviceability requirements. Check deflection limits based on the CBC 07 or IBC 09 specifications.

Connection design: Design the connections between the composite collector beam and the seismic resisting elements. Consider factors such as load transfer, ductility requirements, connection detailing, and constructability. Refer to the applicable code provisions for connection design requirements.

Check for other limit states: Assess other limit states that may be applicable to the composite collector beam, such as web crippling, local buckling, and stability under various loading conditions. Follow the guidelines provided in AISC 360-05 and the specific code requirements (CBC 07 or IBC 09) to ensure the beam’s overall stability and performance.

Documentation and detailing: Prepare detailed drawings and specifications for the composite collector beam, including dimensions, reinforcement requirements, welding details, and any specific construction requirements. Follow the provisions of AISC 360-05, CBC 07, and IBC 09 for proper documentation.