NASCLA Accredited Commercial General ContractorMetalsMedium
A structural steel detailer is preparing shop drawings for a beam-to-column connection. The connection design requires the use of shear tabs welded to the column flange and then bolted to the beam web. What is the primary purpose of the cope or block-out typically specified at the top and bottom corners of the beam web where it connects to the column?
- ATo reduce the overall weight of the beam for easier handling.
- BTo prevent interference with the column flange and allow for full-depth welding of the shear tab.
- CTo accommodate future utility penetrations through the beam web.
- DTo provide clearance for field painting after erection.
Show answer & explanationAnswer & explanation
Correct answer: B. To prevent interference with the column flange and allow for full-depth welding of the shear tab.
Copes (or block-outs) are cut into the beam web at its intersection with the column to prevent the beam web from interfering with the column flange. This clearance allows for the full-depth welding of connection plates (like shear tabs) to the column or for the proper fit-up of the beam itself, ensuring sound connections and preventing stress concentrations.
Why the other options are wrong
- A. The material removed by a cope is minimal and does not significantly reduce the beam's weight.
- C. Utility penetrations are typically designed separately and are larger, often reinforced openings, not small corner copes.
- D. While some clearance can help with painting, it's not the primary structural reason for a cope.
Beam Cope / Block-out
A cut-out or notch made in the web or flange of a beam, typically at its ends, to provide clearance for intersecting members, connection plates, or to allow for proper welding access.
- Essential for proper fit-up of members and connections.
- Prevents interference and stress concentrations.
- Allows for complete and sound welds, especially for shear tabs or moment connections.
Memory trick: Cope Cut: Clear Connection, Clean Weld.