When an earthquake occurs, the severity of damage is determined by natural factors such as the magnitude of the earthquake, the epicenter distance, soil properties, and type of the structures in the affected area, as well as the socio-economic factors such as the population, disaster prevention measures, and economic power of the community. This study evaluated the direct economic loss due to building damage and the community’s recovery ability. Building damage was estimated using fragility functions due to the design earthquake by the seismic design code. The usage of the building was determined from the information in the building registrar. Direct economic loss was evaluated using the standard unit price and estimated building damage. The standard unit price was obtained from the Korean Real Estate Board. The community’s recovery capacity was calculated using nine indicators selected from regional statistical data. After appropriate normalization and factor analysis, the recovery ability score was calculated through relative evaluation with neighboring cities.

For earthquake loss estimation of building structures in Gangnam-Gu district in Seoul, three scenario earthquakes were selected by comparison of the response spectra of these scenario earthquakes with the design spectrum in Korean Building Code (KBC 2009), and then direct losses of the building structures in the Gangnam-Gu district under each scenario earthquake are estimated. The following conclusions are drawn from the results of damage and loss in the second scenario earthquake, which has a magnitude = 6.5 and epicentral distance =15 km: (1) The ratio of building stocks undergoing the extensive and complete damage level is 40.0% of the total. (2) The amount of direct economic losses appears approximately 19 trillion won, which is 1.2% of the national GDP of Korea. (3) About 25% of high-rise (over 10-story) RC building wall structures, were inflicted with the damage exceeding moderate level, when compared to 60% of low-rise building structures. (4) From the economical view point, the main loss, approximately 50%, was caused by the damage in the high-rise RC wall building structures.

지진피해예측시스템(HAZUS)을 이용하여 지진발생 시 지역별 재해규모를 예측할 수 있으며, 이 결과는 실제상황에서는 신속하고 효과적인 피해복구대책을, 가상지진상황에서는 실효성 있는 종합 지진재해대비책을 수립하는데 큰 도움을 줄 수 있다. 지역적 지반특성에 따라 지진동의 크기가 다르게 나타나므로, 지역적 지반특성을 반영한 지반특성분류도를 작성하여 지진재해예측시스템 구현에 적용하면 보다 신뢰성 높은 피해예측 결과를 산출 할 수 있다. 이번 연구에서는 경주지역에서 발생하는 규모 6.7의 가상지진에 대하여 지반특성분류도를 적용한 경우와 그렇지 아니한 경우 지역별 지진재해예측 결과에 차이가 있음을 확인하였다. 지반특성분류도를 적용하지 않았을 경우에는 지진발생위치로부터 거리가 멀어질수록 점차적으로 재해가 작아지는 일정한 형태를 보인다. 그러나 지반특성분류도를 적용한 경우에는 지진발생위치와 지반특성이 동시에 지역별 재해크기에 영향을 미친다. 경주시의 경우 지진발생위치와 가까이 위치하기 때문에 피해규모가 크고, 포항시 남구의 경우 이 지역에 광범위하게 분포하고 있는 연약지반의 영향으로 경주와 비슷한 피해규모가 예상된다.