Summary: | 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.
|