Seismic Analysis

Seismic analysis is the application of physics, historic data, and computer models to determine how a building will perform during an earthquake. This can be applied to designs for new buildings or structures that are already standing. It tries to anticipate whether a building will twist, what frequencies of vibration will be sent through it, and how much force it takes to cause parts of it to fail.

Buildings are subject to dynamic forces even during normal usage. They are often designed to sway a little in strong winds. This is a building's "fundamental mode." When the earth shakes, higher modes of response come into play. The harmonics of a building's response must be understood in order to determine whether it needs to be retrofitted.

A Brief History of Seismic Analysis
In areas subject to earthquakes, building codes have included requirements for seismic readiness since the early 20th century. These codes were updated as greater understanding of the effects of seismic motion was achieved. As computers became available, it become easier to model the effects of an earthquake and design buildings that could resist the forces involved. An arsenal of methods has been created to combat the effects of an earthquake, from shock absorbers built into foundations to "slosh tanks" that are placed high in a tall building, which use the motion and weight of water to counter the vibration of an earthquake.

Seismic analysis is a must when planning a structure in an earthquake-prone area. The safety of future occupants of the building and the prevention (as much as possible) of major property damage depends on it. Qualified engineers can perform this analysis and design the best and most cost-effective ways to minimize earthquake damage. For more information, contact The KPA Group at www.thekpagroup.com.