Understanding EN 81-77: Elevators Designed for Seismic Conditions

What is EN 81-77?

EN 81-77:2013 is a European Standard that defines the design, installation, and operational requirements for elevators in seismic regions. The standard addresses the challenges posed by seismic activity, including the potential for structural damage to the elevator shaft, cabin, and control systems. By setting out specific guidelines for the construction and reinforcement of elevator components, EN 81-77 ensures that elevators remain operational or can be safely evacuated in the event of an earthquake.

Key Provisions of EN 81-77

1. Seismic Risk Assessment and Classification
   
   • Seismic Zones:EN 81-77 categorizes regions based on their seismic risk, ranging from low to high seismicity. The standard requires that the seismic risk of the building site be assessed and that elevators be designed accordingly. This classification determines the level of reinforcement and special features required for the elevator installation.
   
   
   • Seismic Performance Requirements:The standard outlines specific performance requirements based on the seismic zone classification. Elevators in higher seismic zones must meet more stringent requirements to ensure they can withstand stronger earthquake forces.
   
   
2. Structural Reinforcement and Design
   
   • Reinforced Elevator Shaft:EN 81-77 mandates that the elevator shaft be reinforced to withstand seismic forces. This includes ensuring that the walls, guide rails, and other structural components can resist the lateral and vertical forces generated by an earthquake.
   
   
   • Seismic Bracing and Supports:The standard specifies the use of seismic bracing and supports for key elevator components, such as the car frame, counterweight, and guide rails. These reinforcements help maintain the alignment and integrity of the elevator system during an earthquake.
   
   
3. Earthquake Detection and Response Systems
   
   • Seismic Sensors:EN 81-77 requires the installation of seismic sensors that can detect the onset of an earthquake. These sensors trigger the elevator’s earthquake response mode, which includes stopping the elevator at the nearest floor and opening the doors to allow passengers to exit safely.
   
   
   • Automatic Shutdown:The standard mandates that elevators automatically shut down after an earthquake is detected, preventing further use until the system has been inspected and deemed safe. This reduces the risk of entrapment or accidents due to aftershocks or structural damage.
   
   
4. Cabin and Component Safety
   
   • Anti-Derailment Features:EN 81-77 specifies the inclusion of anti-derailment devices that prevent the elevator cabin from leaving the guide rails during an earthquake. This is crucial for maintaining the stability of the cabin and preventing accidents.
   
   
   • Counterweight Safety Measures:The standard requires that counterweights be securely anchored and equipped with safety devices to prevent them from detaching or causing damage during seismic activity. This helps maintain the balance and functionality of the elevator system.
   
   
5. Post-Earthquake Inspection and Maintenance
   
   • Mandatory Inspections:After an earthquake, EN 81-77 requires that all elevators be inspected by qualified personnel before they are returned to service. This inspection must verify that the elevator’s structural components, control systems, and safety features are intact and functioning properly.
   
   
   • Maintenance Protocols:The standard emphasizes the importance of regular maintenance for elevators in seismic zones. This includes routine checks of seismic sensors, bracing systems, and other critical components to ensure they remain in good condition and ready to respond to an earthquake.
   
   

Why EN 81-77 Was Developed

EN 81-77 was developed in response to the unique challenges posed by seismic activity. Elevators are particularly vulnerable during earthquakes due to their vertical shafts, moving components, and reliance on precise alignment. Before the introduction of EN 81-77, there were no standardized requirements for elevators in seismic zones, leading to inconsistent safety measures and increased risks during earthquakes. This standard provides a unified approach to designing and installing elevators that can withstand seismic forces, ensuring the safety of passengers and the integrity of the elevator system.

The Importance of Compliance

1. Enhancing Passenger Safety
   
   • Preventing Accidents:Compliance with EN 81-77 significantly reduces the risk of accidents during and after an earthquake by ensuring that elevators are equipped with safety features designed to withstand seismic forces. This includes preventing derailment, counterweight detachment, and other potential hazards.
   
   
   • Facilitating Safe Evacuation:The standard’s requirements for seismic sensors and automatic shutdown ensure that passengers can safely exit the elevator as soon as an earthquake is detected. This reduces the risk of entrapment or injury during aftershocks.
   
   
2. Protecting Building Infrastructure
   
   • Minimizing Structural Damage:By requiring reinforced shafts and bracing systems, EN 81-77 helps protect the building’s infrastructure from earthquake-related damage. This not only enhances the safety of the elevator system but also reduces the potential for costly repairs and extended downtime.
   
   
   • Ensuring Elevator Functionality Post-Earthquake:The standard’s provisions for post-earthquake inspections and maintenance help ensure that elevators can be returned to service safely and quickly after an earthquake, minimizing disruption to building operations.
   
   
3. Legal and Regulatory Compliance
   
   • Mandatory in Seismic Zones:Compliance with EN 81-77 is mandatory for all new elevator installations in seismic zones within the European Union. Failure to comply can result in legal penalties, including fines and restrictions on building occupancy.
   
   
   • Certification and Building Approvals:Elevators in seismic zones must be certified as meeting EN 81-77 requirements to obtain necessary building approvals. This certification ensures that the elevator is capable of withstanding seismic forces and protecting occupants during an earthquake.
   
   

How BRONZE LIFT Ensures Compliance with EN 81-77

At BRONZE LIFT, we are dedicated to designing and installing elevators that fully comply with EN 81-77. Our elevators are engineered to withstand the forces of an earthquake, with reinforced shafts, seismic sensors, and advanced safety features that protect passengers and the elevator system itself. We work closely with building designers and engineers to ensure that our elevators enhance the overall seismic resilience of the building. Additionally, we offer comprehensive maintenance and inspection services to keep these elevators in top condition, ready to respond in the event of an earthquake.

Conclusion

EN 81-77 is a critical standard for ensuring the safety and functionality of elevators in seismic zones. By understanding and complying with its provisions, building owners and managers can protect the lives of occupants, preserve the integrity of the elevator system, and minimize the impact of seismic events. Contact BRONZE LIFT today to learn more about how we can help you meet and maintain compliance with EN 81-77 in your building’s elevator systems.