A major earthquake occurred in Egypt on August 7, 1847. According to historical records, many people lost their lives and hundreds of buildings were destroyed in the earthquake, whose epicenter was in the Fayum region, approximately 100 kilometers south of Cairo. However, the pyramids remained standing.
In particular, the Great Pyramid of Giza, also known as the Pyramid of Cheops, has been resisting earthquakes and natural effects for approximately 4,600 years. New research published in Scientific Reports has more clearly revealed the engineering logic behind this durability.
Pyramid behaves as one piece
According to Mohamed ElGabry, the lead author of the study, during the 1847 earthquake, some of the outer covering stones of the Giza pyramids became loose and some blocks fell. Despite this, the main body of the pyramids remained largely intact.
Scientists measured natural vibration at approximately 30 different points inside the Great Pyramid. The same vibration behavior was observed in the measurements made in the queen’s chamber, the king’s chamber, ventilation ducts and interior passages, except for very small differences.
According to the research, most of the pyramid naturally vibrates at a frequency of approximately 2.3 hertz. This shows that the structure behaves like a single and solid structure, rather than a scattered mass consisting of disconnected stone blocks.
It is critical that it does not resonate during an earthquake.
According to experts, one of the most important points in the durability of the pyramid is that the vibration frequency of the structure is different from the surrounding ground.
The ground around the pyramid vibrates at a frequency of about 0.6 hertz, while the Great Pyramid vibrates at a frequency of about 2.3 hertz. This difference prevents the pyramid from entering into the same rhythm with the ground during an earthquake and amplifying the shaking.
This prevents the dangerous effect known as resonance in engineering. When resonance occurs, even small vibrations can turn into much larger and destructive movements in the structure.
Mass distribution preserves the pyramid
Their shape also plays a big role in the durability of pyramids. The base of the Great Pyramid of Giza consists of sides, each approximately 230 meters long. The structure narrows as it goes up, and most of its mass is concentrated at the bottom.
This design keeps the center of gravity low and ensures that the structure behaves more balanced against horizontal shocks.
In addition, the pyramid consists of millions of stone blocks, which creates an advantage. The numerous joints between the blocks help dissipate some of the energy released during the earthquake.
Solid ground was also effective
Experts state that the ground on which the Giza Pyramids were built also played an important role in their durability. The platform on which the pyramids are located consists of solid and well-cemented limestone layers, providing a hard and stable foundation for the structure.
This contributes to a more controlled movement transferred from the ground to the structure during an earthquake.
Very different from modern skyscrapers
According to researchers, the behavior of pyramids against earthquakes is quite different from modern high-rise buildings. Today’s skyscrapers are generally designed to absorb earthquake energy by flexing.
The Great Pyramid, on the other hand, is extremely rigid, that is, it acts like a hard and holistic structure. This feature, combined with its wide base, low center of gravity, solid ground and non-resonant vibration structure, allows the pyramid to survive for thousands of years.
According to scientists, the Egyptians built the pyramids with the idea of eternity. New research shows that this desire for “eternity” is supported not only by faith but also by a remarkable architectural and engineering logic.
