EN15129:2018 Clause 5 – Rigid Connection Devices for Seismic Safety
EN15129:2018 Clause 5 is a key European standard governing rigid connection devices-critical components that constrain structural displacements while supporting seismic protection systems. Focused on reliability, compatibility, and performance, this clause categorizes devices into three functional types, outlining clear requirements for materials, design, and testing.
Core Scope and Device Types
Rigid connection devices limit relative movement in one or more directions, with minimal horizontal distortion. Cable restraints are excluded, and supplementary details are in Annex C. The three primary device categories are:
1. Permanent Connection Devices (PCD)
PCDs restrict horizontal translations (one direction for movable types, two for fixed) while allowing vertical movement and full rotations. They do not transmit vertical loads or bending moments, nor do they alter structural natural periods or dissipate energy. Manufactured to EN 1337-8, PCDs rely on structural bearings and follow Eurocode load combination rules (EN 1337-1:2000 Annex B). Common applications include bridge bearings and industrial steel structure connections.
2. Fuse Restraints (FR)
Also called sacrificial restraints, FRs act as rigid connectors under service loads but release suddenly when a preset break-away force is exceeded. This switches the structure from service to seismic mode, enabling isolation/damping systems to operate. FRs are mechanical (MFR) or hydraulic (HFR), with materials complying with EN ISO 898 (fasteners) and EN 1090-2 (welding). Type tests include service load cycling, 2 million repeated load cycles (if required), and break-away force verification (±15% tolerance if unspecified).
3. Temporary Connection Devices (TCD/STU)
Known as Shock Transmission Units (STUs), TCDs exhibit velocity-sensitive behavior: low reaction forces (<10% of design force) for slow thermal movements, and rigid force transmission above 0.5–5 mm/s activation velocity. They feature spherical hinges (≥±2° rotation) and minimum strokes (±50 mm for bridges, ±25 mm for buildings). Materials include ferrous alloys (EN 10025/10088) and non-toxic silicone-based fluids. Testing covers pressure resistance, seal wear (10,000 cycles), impulsive loads, and cyclic seismic simulation.
Key Compliance
Compliance with Clause 5 ensures devices integrate seamlessly with seismic systems, enhancing structural safety.
This clause provides a unified framework for reliable, code-compliant rigid connections-essential for earthquake-resilient buildings, bridges, and industrial structures.
