Introduction

Beam-to-column moment resisting steel joint for moment-resisting frames. By using slip-critical connections, this joint is dissipative, demountable and weld/bolt-free. Dissipation allows for repair costs savings, while deconstructability and absence of welds/bolts facilitate the reuse of structural members.

Technical features

This joint connects beam and column through two seat connections and struts. It places all the bolt-holes and welds off the structural profiles, which are, instead, “clamped” by “ad-hoc” designed friction-based bolted splices. The braces can be easily adjusted and replaced, as they are pinned to these splices. Braces themselves can be used to increment the capacity of existing connections in a reversible manner. Clamp joints use friction strength to resist the serviceability actions, but dissipate by friction hysteresis under the design seismic forces. This way, repair operations can be limited re-bolting or substituting bolts. A secondary dissipation mechanism implies the plasticization of braces under compression. In this case, only braces replacing would be necessary, with no stability-issues associated (as seat connections guarantee stability under gravity loads).

Possible Applications

• Structures for temporary events (i.e. stadium or parking buildings);
• Buildings that need a flexible structural layout (i.e. industrial buildings);
• Reversible retrofitting of existing beam-to-column connections;
• Buildings in seismic-prone areas.

Advantages

• Reusability of structural members after a building’s demolition;
• Reduction of costs and time for repair/reconstruction after seismic-events;
• Structural adaptability for functional needs;
• Improved structural resilience;
• Marketing opportunities in the field of sustainable architecture.