Earthquake Engineering Overview

Earthquake Impact and Casualties

• Over 1.5 million deaths due to earthquakes occurred globally in the 20th century.
• In the early 21st century, fatalities were around half a million.
• Most casualties stem from inadequate seismic resistance of buildings, not the earthquakes themselves.
• Despite extensive research, each significant earthquake reveals new challenges in engineering and safety.

Evolution of Earthquake Engineering

• Fundamental principles of Earthquake Engineering emerged roughly 70 years ago.
• Initial concepts regarding seismic actions and structural responses were limited and have evolved significantly.
• Progress continues to be essential for achieving optimal seismic design.

Seismic Design Challenges

• Balancing earthquake demand (effects of earthquakes on structures) with structural capacity (ability to withstand these effects) is critical.
• Ground motion modeling is crucial for understanding earthquake demand on structures.

Enhancements in Earthquake Monitoring

• Effective seismic hazard identification and risk assessment are vital for mitigation strategies.
• A monitoring system employing regional instrumented networks and satellite observations (such as GPS) has been established.
• Data gathered from these monitoring systems supports better seismic design and safety.

Understanding Earthquake Occurrence

• Significant advancements in seismology over the past decades have improved knowledge of earthquake physics.
• Modern technologies enhance forecasting of long-term seismic activity, yet precise predictions remain challenging due to complex interactions of various processes.

Knowledge of Earthquake Effects

• Critical improvements include understanding and modeling earthquake effects, such as wave propagation and local site conditions.
• Development of synthetic seismograms for forecasting future earthquakes is needed.
• Identifying parameters of ground motions that lead to structural damage, such as peak acceleration and shaking duration, is essential.

Advances in Seismic Design of Structures

• Research focuses on integrated experimentation, theories, databases, and computer simulations to understand structural responses.
• The goal is to establish performance-based earthquake engineering methodologies tailored to varying seismic zones.
• Emphasis on new materials, technologies, and structural systems to enhance earthquake resistance.

Development of Performance-Based Codes

• Next-generation performance-based codes aim to reduce the seismic vulnerability of structures.
• Lessons learned from recent strong earthquakes and advancements in seismology shape these code developments.