The architecture helps the Great Pyramid of Giza stand for 4,600 years

New research published on May 21 in the journal Scientific Reports shows features inside the Great Pyramid of Giza such as the series of decompression chambers above where pharaoh Khufu once rested that help dampen seismic shocks towards the top of the structure.

Theo Live Sciencethe height of the Giza pyramid has only decreased by 10 m since its construction during the Egyptian Old Kingdom (2649-2150 BC). At least two major earthquakes have occurred within a radius of 80 km around the Giza pyramid. In 1847, a magnitude 6.8 earthquake shook the area. In 1992, a 5.8 magnitude earthquake knocked some of the facing stones from the top of the pyramid.

Theo Science Alertthe Giza pyramid was built from 2.3 million stone blocks weighing a total of 6 million tons. These stone blocks are carefully arranged and linked to form a solid structure approximately 147 m high containing only a few hollow rooms. Therefore, the pyramid is very strong with the weight concentrated on the ground and evenly distributed throughout the foundation. But that is not enough to help the project avoid any damage due to earthquakes or time of destruction.

To learn the secret to earthquake resistance, a group of experts led by seismologist Asem Salama at the Egyptian Institute of Astronomy and Geophysics placed 37 acceleration sensors in many different places including the King’s Chamber, the Queen’s Chamber, pressure relief rooms stacked above the King’s Chamber, corridors and tunnels, on the outer stone and the ground around the pyramid. They used a non-invasive technique called “environmental vibration analysis” that measures vibrations transmitted through rock formations, tunnels and internal cavities, thereby understanding how structures react to earthquakes.

Theo National Geographicanalysis results show that the level of vibration in the structure fluctuates on average from 2 to 2.6 hertz, proving that vibrations transmit evenly from one rock block to another, an important sign of stability. Analysis also detected distinct vibrations in the ground around the pyramid, fluctuating around 0.6 hertz. “The pyramid’s vibration frequency is different from the surrounding ground, which can reduce the resonance effect during earthquakes,” Mostafa explained. By reducing resonance, the destructive potential of strong underground vibrations is minimized.

Some other features that contribute to the pyramid’s stability include its large foundation, strong limestone base, and symmetrical geometric design. The vibrations gradually increased towards the top of the structure, but were interrupted by decompression chambers located 61 meters inside the pyramid, above the King’s Chamber, built to relieve some of the weight on the pharaoh’s final resting place. They also help reduce vibrations transmitted to the top of the structure.

The research team is planning to take further measurements at the Giza pyramid and hopes to use the same method at many important archaeological sites in Egypt because some similar features have the potential to protect other pyramids in Giza.