The Green’s function is used to solve the scattering far field solution of SH-wave by a mov-able rigid cylindrical interface inclusion in a linear elastic body.First,a suitable Green’s function is devel-oped,which i...The Green’s function is used to solve the scattering far field solution of SH-wave by a mov-able rigid cylindrical interface inclusion in a linear elastic body.First,a suitable Green’s function is devel-oped,which is the fundamental displacement solution of an elastic half space with a movable rigid half-cylin-drical inclusion impacted by out-of-plane harmonic line source loaded at any point of its horizontal surface.By using the Green’s function,a series of Fredholm integral equations of the first kind which determine thescattering far field can be set up.Then the paper gives the expressions on the far field including the displace-ment mode of scattering wave and the solution of scattering cross-section.Finally,some examples and nu-merical results are discussed to analyze the influence of the combination of different media parameters on theanswer of far field.展开更多
The characteristics of the inelastic response of structures affected by hanging wall and forward directivity in the 1999 Chi-Chi earthquake are investigated. Inelastic displacement ratios (IDRs) for ground motions imp...The characteristics of the inelastic response of structures affected by hanging wall and forward directivity in the 1999 Chi-Chi earthquake are investigated. Inelastic displacement ratios (IDRs) for ground motions impacted by these near- field effects are evaluated and comprehensively compared to far-field ground motions. In addition, the inelastic displacement responses to hanging wall and footwall ground motions are compared. It is concluded that the inelastic displacement response is significantly affected in the short period range by hanging wall and in the long period range by footwall. Although high peak ground acceleration was observed at hanging wall stations, the IDRs for structures on hanging wall sites are only larger than footwall sites in the very long period range. Forward directivity effects result in larger IDRs for periods longer than about 0.5s. Adopting statistical relationships for IDRs established using far-field ground motions may lead to either overestimation or underestimation in the seismic evaluation of existing structures located in near-field regions, depending on their fundamental vibration periods.展开更多
Analysis of GEONET observations covering the entire territory of Japan shows that the great Tohoku-oki earthquake that occurred on March 11, 2011 off the east coast of Honshu in Japan caused an eastward movement of th...Analysis of GEONET observations covering the entire territory of Japan shows that the great Tohoku-oki earthquake that occurred on March 11, 2011 off the east coast of Honshu in Japan caused an eastward movement of the northern part of the island by as much as 5.3 m. The GPS data from TEONET in China were used to derive far-field coseismic displacements and to assess the impact of the Tohoku-oki earthquake on crustal deformation in eastern China. The results reveal that the coseismic horizontal displacements induced by the earthquake are the level of millimeters to centimeters in North and Northeast China, with a maximum of 35 mm. Strain analysis also indicates that the earthquake resulted in an increase in the tensile strain on the north-northeast trending faults in North and Northeast China. The tensile strain imposed on the Yilan-Yitong and Dunhua-Mishan faults is more significant than that imposed on the faults in North China; the maximum normal strain reaches about 40 nano-strain. Considering that the static Coulomb stress loaded on the faults is limited, its effect on the regional seismic activity may not be significant.展开更多
Based on continuous GPS observations within China as well as global GPS tracking network, a calculation has been made of far-field coseismic displacements associated with the December, 2004 (Mw = 9.3) and March, 2005 ...Based on continuous GPS observations within China as well as global GPS tracking network, a calculation has been made of far-field coseismic displacements associated with the December, 2004 (Mw = 9.3) and March, 2005 (Mw = 8.7) earthquakes. The far-field coseismic displacements are associated with the 2004 shock range more than 6000―7000 km in both north-south and east-west dimensions, and depict an undulated wave pattern of contraction and extension. The coseismic displacements associ-ated with the 2005 event, however, are distributed near the epicentral region, and the event itself may be an aftershock of the 2004 earthquake.展开更多
基于软硬互层边坡的有限元模型,研究了边坡在近远场地震作用下的动力响应规律,得出远场地震对边坡动力响应(动力放大系数、最大剪应力和最大主应力)的影响总体比近场地震显著;通过将时程分析法与规范中的拟静力法计算的安全系数进行对比...基于软硬互层边坡的有限元模型,研究了边坡在近远场地震作用下的动力响应规律,得出远场地震对边坡动力响应(动力放大系数、最大剪应力和最大主应力)的影响总体比近场地震显著;通过将时程分析法与规范中的拟静力法计算的安全系数进行对比,明确了拟静力法在地震动力稳定性评价中的不足;基于有限元时程分析法计算出的边坡临界加速度代入Newmark滑块位移法公式中,得到了考虑地震近远场特性影响的边坡永久位移,并与弹塑性有限元数值模拟结果进行了对比,得出Newmark法计算结果偏小,且远场地震作用下的永久位移比近场地震作用下分别增大35%(Newmark法)和21%(弹塑性有限元法);最后基于Jibson and Michae提出的边坡稳定性评价的永久位移量进行了边坡的稳定性评价,得出以永久位移1 cm作为岩质边坡从一个轻度破坏到中度破坏程度的评价临界值较为合理。展开更多
文摘The Green’s function is used to solve the scattering far field solution of SH-wave by a mov-able rigid cylindrical interface inclusion in a linear elastic body.First,a suitable Green’s function is devel-oped,which is the fundamental displacement solution of an elastic half space with a movable rigid half-cylin-drical inclusion impacted by out-of-plane harmonic line source loaded at any point of its horizontal surface.By using the Green’s function,a series of Fredholm integral equations of the first kind which determine thescattering far field can be set up.Then the paper gives the expressions on the far field including the displace-ment mode of scattering wave and the solution of scattering cross-section.Finally,some examples and nu-merical results are discussed to analyze the influence of the combination of different media parameters on theanswer of far field.
基金National Natural Science Foundation of China Under Grant No. 50538050 and No. 50608024
文摘The characteristics of the inelastic response of structures affected by hanging wall and forward directivity in the 1999 Chi-Chi earthquake are investigated. Inelastic displacement ratios (IDRs) for ground motions impacted by these near- field effects are evaluated and comprehensively compared to far-field ground motions. In addition, the inelastic displacement responses to hanging wall and footwall ground motions are compared. It is concluded that the inelastic displacement response is significantly affected in the short period range by hanging wall and in the long period range by footwall. Although high peak ground acceleration was observed at hanging wall stations, the IDRs for structures on hanging wall sites are only larger than footwall sites in the very long period range. Forward directivity effects result in larger IDRs for periods longer than about 0.5s. Adopting statistical relationships for IDRs established using far-field ground motions may lead to either overestimation or underestimation in the seismic evaluation of existing structures located in near-field regions, depending on their fundamental vibration periods.
基金supported by the State Key Laboratory of Earthquake Dynamics (LED2009A02)the National Key Infrastructure Project "Tectonic and Environmental Observation Network in China"
文摘Analysis of GEONET observations covering the entire territory of Japan shows that the great Tohoku-oki earthquake that occurred on March 11, 2011 off the east coast of Honshu in Japan caused an eastward movement of the northern part of the island by as much as 5.3 m. The GPS data from TEONET in China were used to derive far-field coseismic displacements and to assess the impact of the Tohoku-oki earthquake on crustal deformation in eastern China. The results reveal that the coseismic horizontal displacements induced by the earthquake are the level of millimeters to centimeters in North and Northeast China, with a maximum of 35 mm. Strain analysis also indicates that the earthquake resulted in an increase in the tensile strain on the north-northeast trending faults in North and Northeast China. The tensile strain imposed on the Yilan-Yitong and Dunhua-Mishan faults is more significant than that imposed on the faults in North China; the maximum normal strain reaches about 40 nano-strain. Considering that the static Coulomb stress loaded on the faults is limited, its effect on the regional seismic activity may not be significant.
文摘Based on continuous GPS observations within China as well as global GPS tracking network, a calculation has been made of far-field coseismic displacements associated with the December, 2004 (Mw = 9.3) and March, 2005 (Mw = 8.7) earthquakes. The far-field coseismic displacements are associated with the 2004 shock range more than 6000―7000 km in both north-south and east-west dimensions, and depict an undulated wave pattern of contraction and extension. The coseismic displacements associ-ated with the 2005 event, however, are distributed near the epicentral region, and the event itself may be an aftershock of the 2004 earthquake.
文摘基于软硬互层边坡的有限元模型,研究了边坡在近远场地震作用下的动力响应规律,得出远场地震对边坡动力响应(动力放大系数、最大剪应力和最大主应力)的影响总体比近场地震显著;通过将时程分析法与规范中的拟静力法计算的安全系数进行对比,明确了拟静力法在地震动力稳定性评价中的不足;基于有限元时程分析法计算出的边坡临界加速度代入Newmark滑块位移法公式中,得到了考虑地震近远场特性影响的边坡永久位移,并与弹塑性有限元数值模拟结果进行了对比,得出Newmark法计算结果偏小,且远场地震作用下的永久位移比近场地震作用下分别增大35%(Newmark法)和21%(弹塑性有限元法);最后基于Jibson and Michae提出的边坡稳定性评价的永久位移量进行了边坡的稳定性评价,得出以永久位移1 cm作为岩质边坡从一个轻度破坏到中度破坏程度的评价临界值较为合理。
