Pagodas don't fall down primarily because of their unique architectural features and materials:
- They are made mostly of wood, which is flexible and can bend and warp under force without breaking, allowing them to absorb seismic stresses and return to their original shape once the force subsides.
- The structural design uses wooden joints without nails, allowing the wood surfaces in these joints to twist and rub against each other during an earthquake, which dissipates seismic energy and prevents it from traveling up the structure.
- They have a layered, box-like structure where each layer sways slowly and independently, creating a wobbling effect. This sway alternates directions between layers, like a balancing toy, which helps absorb and distribute earthquake forces.
- An internal central pillar, called the shinbashira, acts like a pendulum that stabilizes the structure by constraining excessive sway, sometimes suspended and not bearing the building's full load, enhancing earthquake resistance.
These design principles combined make pagodas extremely resilient to earthquakes, as shown in Japan where they have survived for centuries despite frequent seismic activity and severe earthquakes like the 1995 Hanshin earthquake.
