## Math in Engineering## Civil Engineeringand Mathematics |

## How is mathematics used to enable buildings to withstand earthquakes? |

It is not usually the quake that kills people, but the collapse of structures. In particular, the horizontal shaking during a quake is mostly responsible for causing building or road damage and collapse. Most structures are designed to carry heavy loads, so they are strong in the vertical direction. Designing structures to withstand the horizontal earthquake shaking can save buildings and lives.

There may be other ways to mitigate the amount of structural collapse during quakes that include a healthy dose of simple and complex mathematics. One expensive way would be to design all buildings to withstand the largest ground shaking an area could expect. This could be done using mathematics familiar to designers and engineers; the math involved analyzes how large quake frequency waves travel through and area. Yet another, more practical, solution might be to design buildings to withstand the specific *types* of shaking expected in a region (this could be based on the rock underneath; earthquake waves travel differently in sand and rock). Again, mathematics could be used to determine the frequency at which each building vibrates (or the number of times a building sways per second) versus the potential type of quakes that roll through the area.