Two of the deadliest earthquakes in history occurred on January 17th.

Two of the 10 deadliest earthquakes in recorded history occurred on January 17th. This year marks the 30th anniversary of the Great Hanshin-Awaji Earthquake. Southern California’s Northridge earthquake occurred just one year earlier, in 1994. The two earthquakes killed 6,400 people, injured 45,000, and left 500,000 homeless.

“These two events were seminal for the engineering and infrastructure fields,” said Paolo Bocchini, director of Lehigh University’s Center for Disaster Modeling and Resilience.

“Both disasters changed the way we look at losses from infrastructure failures, spurred the adoption of performance-based design, and perhaps most importantly, catastrophic modeling to continuously improve resilience and readiness.” Awareness of the need for this has increased dramatically.”

performance and functionality.

It took two earthquakes in the 20th century for performance-based design to come to the fore. Its origins date back to the mid-18th century B.C., when in the aftermath of an earthquake the Babylonians proclaimed that “houses should not collapse and kill people.”

The evolution of seismic resistance happened much faster. Society’s expectations have improved dramatically in the 30 years since Hanshin/Awaji and Northridge. The same goes for materials and engineering techniques.

“Life safety considerations are no longer enough,” Bocchini said. “We want our buildings and bridges to be able to withstand large-scale disasters and remain functional, or at least repaired quickly.”

While the community was being rebuilt after the Northridge earthquake, the Los Angeles area economy suffered a $40 billion loss due to loss of use during recovery. Lehigh University researchers are champions of the emerging field of functional recovery engineering, calling it the next evolution of resilience. They introduced a new tool, the “functional fragility curve,” to examine larger structural ex post functions from a broader socio-economic perspective.

Bunkers are very safe, but no one wants to live in a bunker.

“Engineers can design for any target earthquake magnitude, but stronger structures have more complex costs than pure dollars and cents,” Bocchini said. “Resilience is a social, political and behavioral decision. More resilient communities require everyone to understand the threats they face.”

Understanding the basics of earthquakes…

Balance: When the ground shakes, primarily horizontal loads are applied to the structure. Structural collapse occurs vertically. Earthquakes can cause structures to become unbalanced and collapse due to gravity. Behavior: It is behavior, the complex balance of engineering and infrastructure at the intersection of nature and community, that determines the level of damage a structure must withstand. Benefits: There is increasing focus on benefits: infrastructure that saves lives and maintains availability after an earthquake.