https://scholars.lib.ntu.edu.tw/handle/123456789/598001
標題: | Influence of horizontally variable soil properties on nonlinear seismic site response and ground motion coherency | 作者: | Chang Y.-H Tsai C.-C Ge L Park D. YU-NING GE |
關鍵字: | Acoustic wave velocity;Amplification;Shear flow;Shear waves;Soils;Wave propagation;Amplification ratio;Correlation lengths;Ground motion coherency;Ground motion intensities;Ground-motion;Shear modulus reduction curve;Shear wave velocity;Site response;Soil property;Spatial variability;Nonlinear analysis | 公開日期: | 2022 | 卷: | 51 | 期: | 3 | 起(迄)頁: | 704-722 | 來源出版物: | Earthquake Engineering and Structural Dynamics | 摘要: | The objective of this study is to quantify the effect of the spatial variability of soil properties on site response and ground motion coherency. A 2D random field theory is used to simulate soil parameters, including shear wave velocity (Vs) and nonlinear stress–strain curves. Different levels of spatial variability are controlled by coefficient of variation (COV) and correlation length (CL). The wave prorogation is simulated through the 2D finite difference software FLAC2D. Different types of analysis conditions, such as 1D or 2D model, linear or nonlinear analysis, and input motion, are investigated. The increase of Vs variability leads to a decrease in the mean amplification ratio (surface response spectrum to bedrock response spectrum) but an increase in its variation. The effect of the variability of soil nonlinearity on the mean amplification ratio is marginal compared with that induced by Vs variability. However, as the ground motion intensities increase (or more nonlinearity induced), the standard deviation of the simulation normalized by the baseline response increases. Compared with the 2D result, the 1D site response analysis that is commonly used in practice may potentially underestimate the mean amplification ratio but overestimate its variability due to the ignorance of the horizontal soil property variability. In the evaluation of the spatially correlated site response, the ground motion coherency decays significantly, as the COV of Vs and the ground motion intensity increase. The effect of CL on ground motion coherency is minor and limited to a separation distance within two-times of CL. Therefore, a coherency model, which eliminates the CL term but includes the ground motion intensity (i.e., nonlinear effect) parameter, is proposed in this study. It is revealed to yield a better agreement with the simulation results than other coherency models. ? 2021 John Wiley & Sons Ltd. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85120828384&doi=10.1002%2feqe.3587&partnerID=40&md5=c8f4a668dfd4ac873e6ae90d9c5b4312 https://scholars.lib.ntu.edu.tw/handle/123456789/598001 |
ISSN: | 00988847 | DOI: | 10.1002/eqe.3587 |
顯示於: | 土木工程學系 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。