Seismic damage evaluation for low-rise RC school buildings in Taiwan

Earthquake damage is not only a disaster, but also an examination for the present structure engineering technique and a lesson for the future one. By collecting and investigating damage data, the correlation between ground motion and damage can be established directly and applied to earthquake loss estimation and hazard mitigation. ATC-13 report presented a methodology that has been widely used for estimating damage/loss caused by earthquake and collateral hazards. The major procedure includes facility classification, selection of ground motion characterization, and damage estimates for different types of structures under specific ground shaking intensity. Mostly the motion-damage relationship developed by using investigated damage data during a past earthquake is in the form of vulnerability function, also termed fragility curve. It predicts the probability of reaching or exceeding specific damage state for a category of buildings with given earthquake intensity. The vulnerability functions are feasible for damage loss estimate in a large region, such as a city or a state, yet scatter caused by insufficiency of detail in structure classification exists generally. The applicability of the functions to regions outside the area where it is originally developed is unclear as well. Seismic evaluation that concerns about localized structural behavior and ground motion characteristics is utilized to establish the motion-damage relationship for individual buildings. While detailed information and complicated calculation are required, higher accuracy and applicability may be expected. Vulnerability functions can also be developed by performing seismic evaluation procedure on representative type of model buildings.