Structure and Features of Tokyo Tower
Tokyo Tower, completed in 1958, is a 333-meter-tall communications tower. At the time of its construction, it was the tallest self-supporting steel tower in the world. The main structure consists of a reinforced concrete foundation at the base and a steel truss structure above. This design enhances its resistance to wind and earthquakes.
Seismic Design of Tokyo Tower
Tokyo Tower was designed based on the seismic standards at the time of its construction. After the Great Hanshin Earthquake in 1995, extensive renovations were carried out to improve its earthquake resistance. The following seismic reinforcements were implemented:
- Installation of steel pipe braces
- Installation of damping devices
- Reinforcement of the foundation
These renovations brought Tokyo Tower’s seismic performance up to the level of current seismic standards.
Magnitude of Earthquakes Tokyo Tower Can Withstand
After the seismic retrofitting, Tokyo Tower is designed to withstand earthquakes with an intensity of upper 6 to 7 on the Japan Meteorological Agency seismic intensity scale, equivalent to the Great Hanshin Earthquake. However, there is a possibility of amplified shaking on higher floors due to long-period ground motion.
Safety Measures at Tokyo Tower
Tokyo Tower has implemented the following safety measures in case of an earthquake:
- Introduction of an earthquake warning system
- Regular seismic diagnostics and reinforcement work
- Evacuation drills
- Securing emergency supplies
These measures help minimize damage during an earthquake and ensure the safety of visitors.
Conclusion
Tokyo Tower was designed based on the seismic standards at the time of its construction and underwent extensive seismic retrofitting after the Great Hanshin Earthquake. It is now designed to withstand earthquakes with an intensity of upper 6 to 7. Furthermore, various safety measures are in place to minimize damage and ensure visitor safety during an earthquake. As a symbol of Tokyo, Tokyo Tower will continue to captivate people while maintaining its safety.
