摘要: |
为实现一致倒塌风险,对风险导向地震动参数进行了研究.首先,基于ArcGIS Engine平台,采用离散算法对西安地区的计算控制点进行了概率地震危险性分析;然后,根据地震危险性分析得到的年超越概率曲线,考虑结构的地震易损性,基于地震动决策参数已有的研究成果,通过风险积分得到了各计算控制点的风险导向巨震、大震、中震的地震动参数PGARV、PGARM、PGARD,并计算了风险系数Rc(风险导向大震的地震动强度与大震对应地震动强度之比)以及风险导向巨震、风险导向大震与风险导向中震地震动参数的比例关系K1、K2;最后,分别取结构易损性对数标准差βR为0.5、0.6、0.7、0.8、0.9、1.0,通过参数影响分析研究了βR对PGARM、Rc、K1和K2的影响.研究结果表明:倒塌概率并不会随着极罕遇地震对应地震动强度的增加而增加;PGARM、Rc、K1和K2都随着βR的增加而增加;βR越大,对PGARM和Rc的影响越大,对K1和K2的影响不变;K1和K2比PGARM和Rc对βR敏感,K1对βR最敏感.本文得到的西安地区的风险导向地震动参数可以为抗震设计提供参考. |
关键词: 风险导向地震动参数 风险积分 风险系数 易损性对数标准差 参数影响分析 |
DOI:10.11918/202004101 |
分类号:TU312 |
文献标识码:A |
基金项目:国家自然科学基金(51678209) |
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Determination of risk-targeted ground motion parameters in Xian region |
WANG Cong1,2,Lü Dagang1,2
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(1.Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, Harbin 150090, China; 2.Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters (Harbin Institute of Technology), Ministry of Industry and Information Technology, Harbin 150090, China)
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Abstract: |
To achieve consistent collapse risk, 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. |
Key words: risk-targeted ground motion parameters risk integral risk coefficient logarithmic standard deviation of fragility parameter effect analysis |