Expected earthquake loss of RC structures -- Illustrated by medium-rise commercial buildings

• Main Authors: Tu, Yi-Hsuan, 杜怡萱
• Other Authors: Sheu Maw-Shyong
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/41527122984189869920

碩士 === 國立成功大學 === 建築(工程)學系 === 86 === Earthquake insurance plays an important role for risk relief and financial support of the recovery after disaster. However, many insurers in U.S.A. paid unexpectedly compensation in several earthquakes lately. Therefore, how to evaluate earthquake losses accurately and how to set up proper insurance rates for building structures are worthy to investigate. A method which combines seismic damage assessment and repair cost is developed in this paper. Repair cost is taken as a reasonable quantitative index of seismic damage. Earthquake risk assessment of RC structures is proposed as reference for earthquake insurance rate of similar structures. Theoretical simulation and statistics are mostly used methods in evaluation of expected earthquake loss. Due to the lack of field records of earthquake loss in Taiwan, deterministic analysis is adopted by this paper. Nonlinear incremental spectrum analysis is used as seismic damage assessment. Repair costs are calculated during the analysis. The annual expected loss is estimated as overall loss for all possible earthquakes in an year. The conclusions of this thesis are as follows: 1. Repair cost of RC elements: Before ultimate state, repair costs are calculated according to the crack length. Flexural and shear cracks are calculated respectively from semi-empirical formula. After ultimate state, repair costs are determined based on damage modes. 2. Seismic damage assessment: Examples are medium-rise commercial buildings designed with actual procedure. The calculated repair cost is almost proportional to PGA and nearly 70% of repair cost is due to flexural cracks. Weaker structures results in nearly 30% increase of repair cost. 3. Expected earthquake loss and insurance rate: Earthquake loss is defined as the ratio of the repair cost to the replacement cost. Annual expected loss(AEL) is calculated as the integration over annual exceedance probabilities and relative earthquake loss. Most of AEL is accumulated from small and medium earthquakes. However, the integrating range and insurance rates can be adjusted by changing the down pay coverage. The calculated insurance rates are higher in high-risk regions due to earthquake frequency.