Boerdo piling technique: earthquake-resistant polygonal masonry used in Japanese castles

Boerdo piling technique: earthquake-resistant polygonal masonry used in Japanese castles. Boerdo piling is a Japanese technique for building stone walls using large rocks fitted together with cracks filled by pebbles and smaller stones The technique creates sloped walls with ovate shapes resembling Japanese boerdo plant blossoms No mortar was used, allowing stones to move slightly during earthquakes without causing wall damage

Burdock piling: Japanese castle walls fitted without mortar so stones shift during earthquakes—similar to ancient Peruvian stonework. Brilliant engineering.

Key Facts

• Boerdo piling is a Japanese technique for building stone walls using large rocks fitted together with cracks filled by pebbles and smaller stones
• The technique creates sloped walls with ovate shapes resembling Japanese boerdo plant blossoms
• No mortar was used, allowing stones to move slightly during earthquakes without causing wall damage
• Boerdo piling evolved from an earlier technique called disordered piling
• Polygonal masonry with interlocking stones provides more stability than regular brick walls with mortar
• This engineering style is similar to ancient Peruvian stonework
• The technique was essential for structures in earthquake zones like Japan and Peru

Source: The Enormous Megaliths of Osaka Castle in Japan by Ancient Architects