This study is aimed at developing statistical equations to estimate the inelastic displacement ratio of singledegree-of-freedom systems subjected to far fault repeated earthquakes. In the study, peak ground motion par...This study is aimed at developing statistical equations to estimate the inelastic displacement ratio of singledegree-of-freedom systems subjected to far fault repeated earthquakes. In the study, peak ground motion parameters are used to define the scatter of the original data. The ratio of peak ground acceleration to peak ground velocity, and peak ground velocity of the ground motion records and structural parameters such as period of vibration and lateral strength ratio are used in the proposed equations. For the development of the equations, nonlinear time history analyses of single-degree-offreedom systems are conducted. Then, the results are used in a multivariate regression procedure. The equations are verified by comparing the estimated results with the calculated results. The average error and coefficient of variation of the proposed equations are presented. The analyses results revealed that the direct use of peak ground motion parameters for the estimation of inelastic displacement ratio significantly reduced the scatter in the original data and yielded accurate results. From the comparative results it is also observed that results obtained using equations specific to peak ground velocity or peak ground acceleration to peak ground velocity ratio are similar.展开更多
On the basis of 10935 broadband velocity records of 135 earthquakes （ML3.0-6.4 and epicentral distance of 26-623 km） occurred from May 12 to June l0 in 2008, which are collected from 27 bedrock stations included in ...On the basis of 10935 broadband velocity records of 135 earthquakes （ML3.0-6.4 and epicentral distance of 26-623 km） occurred from May 12 to June l0 in 2008, which are collected from 27 bedrock stations included in Sichuan Earthquake Monitoring Network, the corresponding acceleration records are obtained by a real-time simulation method. Then by regression analysis on the data, the relation between the peak ground acceleration and velocity attenuation of small and moderate bedrock earthquakes occurred in Sichuan region is acquired. And the relation is verified by a M4.8 earthquake took place recently in Wenchuan. Finally, the attenuation relations, which are coincident to the geological conditions in Sichuan region, are proposed by studying the records from Sichuan earthquake network.展开更多
We collect 1974 broad-band velocity records of 94 earthquakes (ML=2.84.9, △=13462 km) from seven stations of the Fujian Seismic Network from March 1999 to March 2007. Using real-time simulation, we obtain the corresp...We collect 1974 broad-band velocity records of 94 earthquakes (ML=2.84.9, △=13462 km) from seven stations of the Fujian Seismic Network from March 1999 to March 2007. Using real-time simulation, we obtain the corresponding acceleration and then adopt different models to analyze the seismic data. As a result, a new attenuation relationship between PGA and PGV of the small and moderate earthquakes on bedrock site in Fujian region is established. The Yongchun earthquake occurred recently verifies the attenuation relationship well. This paper provides a new approach for studying the ground motion attenuation relationship using velocity records.展开更多
The MS8.0 Wenchuan earthquake induced severe landslide hazards.For the first time in China,large numbers of strong motion records were obtained during the Wenchuan earthquake,providing the opportunity to study the rel...The MS8.0 Wenchuan earthquake induced severe landslide hazards.For the first time in China,large numbers of strong motion records were obtained during the Wenchuan earthquake,providing the opportunity to study the relationships between ground-motion parameters and the earthquake-induced landslides.Nearly 40 groups of records from the main shock distributed along the Longmenshan fault lines were used to carry out this study.The results appropriate to the Longmenshan area are as follows：1 The threshold of the peak ground acceleration（PGA） is about 0.7 m/s2.When the PGA reaches 2 m/s2,the landslide hazards are very serious; 2 The threshold of the peak ground velocity（PGV） is about 0.5 m/s.When the PGV reaches 1.5 m/s,severe landslide hazards will be induced; 3 The threshold for the Arias intensity（Ia） is about 0.2 m/s.When the Ia in one horizontal direction reaches 2 m/s,landslide hazards will be very serious; 4 As for the relevance order of the parameters to earthquake-induced landslides,Ia is the leading parameter,followed by PGV,and finally PGA.The results presented in this paper are consistent with the results from other studies,indicating that the threshold of the ground motion parameters for strong earthquakes is of the same order of magnitude as that of moderate earthquakes.Landslide density of local sites fluctuated with the increase of ground motion intensity if the thresholds were reached.When the upper limits are exceeded,the landslide density remains at a certain level with relatively little variation.展开更多
文摘This study is aimed at developing statistical equations to estimate the inelastic displacement ratio of singledegree-of-freedom systems subjected to far fault repeated earthquakes. In the study, peak ground motion parameters are used to define the scatter of the original data. The ratio of peak ground acceleration to peak ground velocity, and peak ground velocity of the ground motion records and structural parameters such as period of vibration and lateral strength ratio are used in the proposed equations. For the development of the equations, nonlinear time history analyses of single-degree-offreedom systems are conducted. Then, the results are used in a multivariate regression procedure. The equations are verified by comparing the estimated results with the calculated results. The average error and coefficient of variation of the proposed equations are presented. The analyses results revealed that the direct use of peak ground motion parameters for the estimation of inelastic displacement ratio significantly reduced the scatter in the original data and yielded accurate results. From the comparative results it is also observed that results obtained using equations specific to peak ground velocity or peak ground acceleration to peak ground velocity ratio are similar.
文摘On the basis of 10935 broadband velocity records of 135 earthquakes （ML3.0-6.4 and epicentral distance of 26-623 km） occurred from May 12 to June l0 in 2008, which are collected from 27 bedrock stations included in Sichuan Earthquake Monitoring Network, the corresponding acceleration records are obtained by a real-time simulation method. Then by regression analysis on the data, the relation between the peak ground acceleration and velocity attenuation of small and moderate bedrock earthquakes occurred in Sichuan region is acquired. And the relation is verified by a M4.8 earthquake took place recently in Wenchuan. Finally, the attenuation relations, which are coincident to the geological conditions in Sichuan region, are proposed by studying the records from Sichuan earthquake network.
基金Joint Seismological Science Foundation of China (105034)
文摘We collect 1974 broad-band velocity records of 94 earthquakes (ML=2.84.9, △=13462 km) from seven stations of the Fujian Seismic Network from March 1999 to March 2007. Using real-time simulation, we obtain the corresponding acceleration and then adopt different models to analyze the seismic data. As a result, a new attenuation relationship between PGA and PGV of the small and moderate earthquakes on bedrock site in Fujian region is established. The Yongchun earthquake occurred recently verifies the attenuation relationship well. This paper provides a new approach for studying the ground motion attenuation relationship using velocity records.
基金supported by the National Natural Science Foundation of China under the grant No. 40872209
文摘The MS8.0 Wenchuan earthquake induced severe landslide hazards.For the first time in China,large numbers of strong motion records were obtained during the Wenchuan earthquake,providing the opportunity to study the relationships between ground-motion parameters and the earthquake-induced landslides.Nearly 40 groups of records from the main shock distributed along the Longmenshan fault lines were used to carry out this study.The results appropriate to the Longmenshan area are as follows：1 The threshold of the peak ground acceleration（PGA） is about 0.7 m/s2.When the PGA reaches 2 m/s2,the landslide hazards are very serious; 2 The threshold of the peak ground velocity（PGV） is about 0.5 m/s.When the PGV reaches 1.5 m/s,severe landslide hazards will be induced; 3 The threshold for the Arias intensity（Ia） is about 0.2 m/s.When the Ia in one horizontal direction reaches 2 m/s,landslide hazards will be very serious; 4 As for the relevance order of the parameters to earthquake-induced landslides,Ia is the leading parameter,followed by PGV,and finally PGA.The results presented in this paper are consistent with the results from other studies,indicating that the threshold of the ground motion parameters for strong earthquakes is of the same order of magnitude as that of moderate earthquakes.Landslide density of local sites fluctuated with the increase of ground motion intensity if the thresholds were reached.When the upper limits are exceeded,the landslide density remains at a certain level with relatively little variation.
