risk-targeted ground motion parameters were investigated. First
based on the ArcGIS Engine software
a discrete algorithm was used to analyze the probability of seismic hazard in Xian region. Then
by considering the seismic fragility of the structure
the risk-targeted ground motion parameters of very rare earthquake
maximum considered earthquake
and design basis earthquake for each control point were obtained by risk integral based on the annual exceeding probability curves obtained from seismic hazard analysis and the ground motion decision parameters obtained from existing research results. The risk-targeted ground motion parameters were denoted as PGARV
PGARM
and PGARD
respectively. The relation between the risk coefficient Rc (defined as the ratio of PGARM to the ground motion intensity corresponding to maximum considered earthquake) and K1 (defined as the ratio of PGARV to PGARD) and K2 (defined as the ratio of PGARM to PGARD) were calculated. Finally
based on the parameter effect analysis
the effect of βR (i.e.
logarithmic standard deviation of structural fragility) on PGARM
Rc
K1
and K2 was investigated with its value chosen to be 0.5
0.6
0.7
0.8
0.9
and 1.0
respectively. Results show that the collapse probability did not increase with the increase of the ground motion intensity corresponding to very rare earthquake. Parameters PGARM
Rc
K1
and K2 all increased with the increase of βR. The larger βR was
the greater the effect on PGARM and Rc was
while the effect on K1 and K2 remained unchanged with increasing βR. Compared with PGARM and Rc
K1 and K2 were more sensitive to βR
and K1 was the most sensitive to βR among all the parameters. The risk-targeted ground motion parameters obtained in Xian region can provide references for seismic design.