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🏚️ Earthquake

Build a structure and survive an earthquake! Explore seismology and engineering. Age: 8+

Build & Play3DEasy60 FPS🌍 Earth

🏢 Earthquake — Building Collapse Simulation

Put your building designs to the test! Construct a structure, then trigger earthquakes to see how seismic waves propagate and how different designs resist — or fail to resist — collapse.

🔬 What It Demonstrates

The building is a damped oscillator shaken through its foundations: ẍ + 2ζω₀ẋ + ω₀²x = −ẍ(ground). Its natural frequency follows the standard code rule of thumb f₀ ≈ 1/(0.1·N) for an N-storey frame, so a 2-storey block rings at 5 Hz and a 15-storey tower at 0.67 Hz. When the shaking frequency approaches f₀ the sway is amplified by up to 1/(2ζ) — about 10× for masonry, 25× for a lightly damped steel frame — and that is what breaks the building, not the raw magnitude.

🎮 How to Use

Add floors (this lowers the building's natural frequency, shown in the panel), pick a material, then set the magnitude and the shaking frequency and hit Earthquake. Sweep the frequency slider towards f₀ and watch the roof gain climb — that is resonance. "Random quake" draws an event from a Gutenberg–Richter catalogue (b ≈ 1), so small tremors are common and big ones rare.

💡 Did You Know?

The 1985 Mexico City earthquake collapsed buildings of 8–18 storeys while shorter and taller buildings survived. Soft lake-bed soil amplified seismic waves at exactly the resonant frequency of those specific buildings.

⚙ Under the hood

Build a brick, steel or wood tower, dial up the magnitude, then hit Earthquake! and see which floors survive. Ages 8+.

earthquake simulation kidsbuilding collapseseismic physics3D earthquake

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install